Clinical prediction of extra-medical use of prescription pain relievers from a representative United States sample.

Use of prescription opioids 'beyond the bounds' of medical guidance can lead to opioid dependence. Yet recent efforts to predict extra-medical use of prescription pain relievers (EMPPR) have relied on electronic medical or pharmacy records. Because peak incidence of EMPPR occurs during adolescence- a time of relative health- administrative data may be inadequate. In this study, with data from a United States (US) population sample, we develop and internally validate an EMPPR prediction model. We analyzed data from 234,593 individuals aged 12-to-17-years, as sampled by the US National Survey of Drug Use and Health, 2004-2018, an annual cross-sectional survey. We encoded 14 predictors with onset prior to EMPPR initiation, including age, sex, and facets of drug and psychiatric history. We ranked these predictors by clinical utility before sequentially adding each to a regularized logistic regression model. On held-out test data (n = 23,685), the model performs well with 14 predictors, with an area under the precision recall curve (AUPRC) is 0.155. The area under the receiver operator curve (AUC) is 0.819, exceeding a recent benchmark on this dataset. Results are robust to survey redesign that occurred in 2015, and are not moderated by past-year use of medical services. In conclusion, while selection of predictors is limited to those with known timing prior to initiation of EMPPR rather than any cross-sectional variable, this model discriminates well. Good classification occurs even with a small set of clinically available predictors- age, a history of depression and alcohol, cigarette, and cannabis use.

Ultrasound Imaging Is Reliable for Tibialis Posterior Size Measurements.

OBJECTIVES: The tibialis posterior (TP) is a vital muscle for controlling the medial longitudinal arch of the foot during weight-bearing activities. Dysfunction of this muscle is associated with a variety of pathologic conditions; thus, it is important to reliably assess its morphologic characteristics. Ultrasound (US) has been used to assess characteristics of TP tendons but not the muscle cross-sectional area (CSA). The purpose of this study was to establish a reliable US technique to measure the TP CSA and thickness. METHODS: Twenty-three healthy volunteers participated. We evaluated the CSA and thickness at 4 measurement locations (anterior and posterior views at both 30% and 50% of the shank length). RESULTS: The participants included 12 female and 11 male volunteers (mean age ± SD, 31.23 ± 14.93 years). Excellent reliability was seen for the CSA and thickness at all locations (intraclass correlation coefficients, 0.988-0.998). Limits of agreement (LoA) and standard errors of the measurement (SEMs) were slightly lower at the 30% locations (LoA at 30%, 4.6-9.2; LoA at 50%, 6.4-9.7; SEM at 30%, 0.03-0.05; SEM at 50%, 0.04-0.07). Strong correlations were seen between anterior and posterior measurements of the CSA (30%, r = 0.99; P < .0001; 50%, r = 0.94; P < .0001) and thickness (30%, r = 0.98; P < .0001; 50%, r = 0.95; P = .0001). CONCLUSIONS: Based on these results, the TP can be measured accurately with US at any of the tested locations. Due to the ease of collection and the quality of the data, we recommend the anterior view at 30% of the shank length to measure the CSA. The ability to assess muscle size of the TP will aid in a variety of medical and research applications.

Definitive Closure Using an Ovine Reinforced Tissue Matrix in Contaminated Penetrating Abdominal Trauma.

BACKGROUND Cases involving penetrating abdominal trauma may be complex and often involve damage to multiple organ systems. Synthetic, biologic, and reinforced biologic matrices/reinforced tissue matrices (RBMs/RTMs) are frequently used in hernia repair and other surgical procedures requiring reinforcement, including trauma cases that require abdominal repair. CASE REPORT The first case was a 35-year-old male patient with a stab wound (SW) to the right side of the chest and the abdomen resulting in damage to the diaphragm, epicardium, liver, and duodenum. The second case was a 22-year-old male patient who suffered multiple traumas after an automated trencher accident, including a skull fracture with exposed brain and major lacerations to the shoulder and abdomen causing a large right-flank hernia. In both cases, OviTex® (TELA Bio, Inc., Malvern, PA), a reinforced tissue matrix (RTM), was used to help obtain and maintain abdominal wall closure. We also present an institutional economic analysis using data from the author's institution with average case cost and future projections for procedure volume and product usage volume through 2021. CONCLUSIONS We report favorable outcomes in a series of patients with contaminated (CDC Wound Class III) surgical fields who underwent abdominal wall closure and reinforcement with OviTex RTM. Our work adds to the growing body of literature suggesting that reinforced biologics offer a potential alternative to biological meshes in the setting of a contaminated surgical field. Additionally, in comparison to other commonly available biologic matrices, use of OviTex RTM may be a cost-effective option to achieve abdominal wall closure even in complex cases.

Alcohol use disorder in sexual minority adults: Age- and sex- specific prevalence estimates from a national survey, 2015-2017.

BACKGROUND: Alcohol use disorders (AUD) occur frequently in sexual minority (SM) adults (identifying as gay, lesbian or bisexual). Age-specific prevalence estimates, particularly during middle and older ages, remain obscure. With questions for sexual identity recently included in the National Survey of Drug Use and Health (NSDUH), increased precision is possible. This study investigates the age-specific estimate for AUD in sexual minority versus sexual majority adults. METHODS: Analysis of the 2015-2017 NSDUH, ages 18-years-and-older (N = 128,740). We estimate age-specific, 12-month DSM-IV AUD prevalence and adjusted prevalence ratios (via Poisson regression) by sexual identity. Adjusted models control for demographic, social, and mental health variables. Post-hoc analysis included age-specific estimates after redefining SM to include any same-sex attraction. RESULTS: The age-specific estimate showed peak AUD prevalence at age ∼28 for all SMs, compared to age ∼23 for heterosexuals. By subgroup, gay men ages 18-23, had the highest AUD prevalence at 18.8% (CI: 13.5%, 25.5%). Bisexual women ages 24-29 had the highest disparity, a prevalence ratio (reference heterosexual women) of 2.59 (CI: 2.15, 3.13). Above age 50, the definition of SM is salient: in this age group, prevalence of AUD converges for heterosexuals and SMs that include individuals with any same-sex attraction. CONCLUSION: In this largest study to date, SMs have a high prevalence of AUD. A disparity in the age-by-age estimates emerges by age 25 when AUD occurrence declines in heterosexuals but increases in SMs. A prevalence disparity occurs with each successive age strata, but by age 50-and-older, the difference is null.

AMPA and kainate receptors mediate mutually exclusive effects on GABA(A) receptor expression in cultured mouse cerebellar granule neurones.

Studies on animal models of epilepsy and cerebellar ataxia, e.g., stargazer mice (stg) have identified changes in the GABAergic properties of neurones associated with the affected brain loci. Whether these changes contribute to or constitute homeostatic adaptations to a state of altered neuronal excitability is as yet unknown. Using cultured cerebellar granule neurones from control [+/+; alpha-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate receptor (AMPAR)-competent, Kainate receptor (KAR)-competent] and stg (AMPAR-incompetent, KAR-competent), we investigated whether non-NMDA receptor (NMDAR) activity regulates GABA(A) receptor (GABAR) expression. Neurones were maintained in 5 mmol/L KCl-containing basal media or depolarizing media containing either 25 mmol/L KCl or the non-NMDAR agonist kainic acid (KA) (100 micromol/L). KCl- and KA-mediated depolarization down-regulated GABAR alpha1, alpha6 and beta2, but up-regulated alpha4, beta3 and delta subunits in +/+ neurones. The KCl-evoked but not KA-evoked effects were reciprocated in stg neurones compatible with AMPAR-regulation of GABAR expression. Conversely, GABAR gamma2 expression was insensitive to KCl-mediated depolarization, but was down-regulated by KA-treatment in a 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)-reversible manner in +/+ and stg neurones compatible with a KAR-mediated response. KA-mediated up-regulation of GABAR alpha4, beta3 and delta was inhibited by L-type voltage-gated calcium channel (L-VGCC) blockers and the Ca2+/calmodulin-dependent protein kinase inhibitor, 4-[(2S)-2-[(5-isoquinolinylsulfonyl)methylamino]-3-oxo-3-(4-phenyl-1-piperazinyl)propyl] phenyl isoquinoline sulfonic acid ester (KN-62). Up-regulation of GABAR alpha4 and beta3 was also prevented by calcineurin (CaN) inhibitors, FK506 and cyclosporin A. Down-regulation of GABAR alpha1, alpha6 and beta2 was independent of L-VGCC activity, but was prevented by inhibitors of CaN. Thus, we provide evidence that a KAR-mediated and at least three mutually exclusive AMPAR-mediated signalling mechanisms regulate neuronal GABAR expression.

Aberrant GABA(A) receptor expression in the dentate gyrus of the epileptic mutant mouse stargazer.

Stargazer (stg) mutant mice fail to express stargazin [transmembrane AMPA receptor regulatory protein gamma2 (TARPgamma2)] and consequently experience absence seizure-like thalamocortical spike-wave discharges that pervade the hippocampal formation via the dentate gyrus (DG). As in other seizure models, the dentate granule cells of stg develop elaborate reentrant axon collaterals and transiently overexpress brain-derived neurotrophic factor. We investigated whether GABAergic parameters were affected by the stg mutation in this brain region. GABA(A) receptor (GABAR) alpha4 and beta3 subunits were consistently upregulated, GABAR delta expression appeared to be variably reduced, whereas GABAR alpha1, beta2, and gamma2 subunits and the GABAR synaptic anchoring protein gephyrin were essentially unaffected. We established that the alpha4 betagamma2 subunit-containing, flunitrazepam-insensitive subtype of GABARs, not normally a significant GABAR in DG neurons, was strongly upregulated in stg DG, apparently arising at the expense of extrasynaptic alpha4 betadelta-containing receptors. This change was associated with a reduction in neurosteroid-sensitive GABAR-mediated tonic current. This switch in GABAR subtypes was not reciprocated in the tottering mouse model of absence epilepsy implicating a unique, intrinsic adaptation of GABAergic networks in stg. Contrary to previous reports that suggested that TARPgamma2 is expressed in the dentate, we find that TARPgamma2 was neither detected in stg nor control DG. We report that TARPgamma8 is the principal TARP isoform found in the DG and that its expression is compromised by the stargazer mutation. These effects on GABAergic parameters and TARPgamma8 expression are likely to arise as a consequence of failed expression of TARPgamma2 elsewhere in the brain, resulting in hyperexcitable inputs to the dentate.

Studies on the subtype selectivity of CP-101,606: evidence for two classes of NR2B-selective NMDA receptor antagonists.

The subtype-selectivity of racemic [(3)H]CP-101,606, a novel high-affinity NMDA receptor radioligand was determined using defined recombinant NMDA receptor subunits expressed in HEK 293 cells. [(3)H]CP-101,606 binds to adult rodent forebrain and NR1/NR2B receptors expressed in HEK 293 cells with K(D)=4.2 nM and 6.0 nM, respectively. In contrast, no high affinity specific binding was detected to NR1, NR2A, NR2B subunits expressed alone or NR1/NR2A receptors. HEK 293 cells were transfected with NR1, NR2A and NR2B receptor subunits and complexes comprising all three subunits were isolated by anti-NR2A immunoaffinity chromatography. Based on immunoblotting with subunit-selective antibodies, the immunopurified material contained all three NMDA receptor subunit polypeptides. However, in contrast to parallel studies in which high affinity [(3)H]Ro-25,6981 binding activity was observed, no high affinity [(3)H]CP-101,606 binding sites were detected to the immunopurified material. This study provides further evidence for two distinct classes of NR2B-directed NMDA receptor antagonists, one which binds with high affinity irrespective whether another NR2 subunit type is present (Ro-25,6981) and a second class which is affected significantly by the presence of another NR2 subunit type within the receptor complex, exemplified by CP-101,606.

Immunohistochemical localization of N-methyl-D-aspartate receptor subunits in the adult murine hippocampal formation: evidence for a unique role of the NR2D subunit.

NMDA receptors were immunopurified from adult mouse forebrain and screened by immunoblotting. NR1 was co-associated with NR2A, NR2B and NR2D but not NR2C, nor was NR2C detected in adult mouse hippocampal membranes. The anatomical distribution of NR1, 2A, 2B and 2D was mapped in the adult murine hippocampal formation. NR1-like immunoreactivity was localised to cell bodies of pyramidal neurons, granule cells and hilar cells of the dentate gyrus. Apical dendrites of the CA subfields and hilar cells were also immunopositive. NR2A- and NR2B-like immunoreactivity essentially co-localised with that of NR1 implying co-assembly of all three subunits in this brain structure. NR2D-like immunoreactivity was distinct, being totally excluded from pyramidal, granule and hilar cell bodies. Strong, punctate staining was restricted to the oriens layer of CA1 and the stratum lucidum of CA3 consistent with labelling of presynaptic receptors. Less intense staining was also observed in the internal third of the molecular layer of the dentate gyrus.

Cerebral hemodynamics immediately following carotid occlusion.

During carotid endarterectomy, we routinely monitor internal carotid artery pressure (P(ICA)) and middle cerebral artery flow velocity (V(MCA)). P(ICA) has been previously shown to accurately reflect pressure at the origin of the middle cerebral artery, even during times of rapidly changing pressure such as occurs with sudden occlusion of the common carotid artery. We retrospectively analyzed pressure recordings around the time of carotid cross clamping in 29 consecutive carotid endarterectomy operations. Suitable transcranial Doppler recordings of V(MCA) were available from eight of the operations. Comparing the cardiac cycle prior to cross clamping with the first complete cardiac cycle after cross clamping, the mean P(ICA) fell from 93 mm Hg to 62 mm Hg and the mean V(MCA) fell from 41 cm x sec-1 to 25 cm x sec-1. Over the subsequent 10 seconds, there was a further decrease in P(ICA) to 51 mm Hg (P <.0001), while V(MCA) changed in the opposite direction, increasing to 32 cm x sec-1 (P <.01). The patients with the greatest decrease in P(ICA) immediately on cross clamping also had the greatest additional decrease over the following 10 seconds (r = 0.74). The increase in V(MCA) during the first 10 seconds after carotid occlusion is well recognized and is presumed to be due to autoregulatory vasodilatation. The simultaneous decrease that we observed in P(ICA) indicates an increase in the pressure gradient along the collateral vessels, which is to be expected during a period of increasing flow along those vessels.

A randomized crossover comparison of the effects of propofol and sevoflurane on cerebral hemodynamics during carotid endarterectomy.

BACKGROUND: Intravenous and inhalational anesthetic agents have differing effects on cerebral hemodynamics: Sevoflurane causes some vasodilation, whereas propofol does not. The authors hypothesized that these differences affect internal carotid artery pressure (ICAP) and the apparent zero flow pressure (critical closing pressure) during carotid endarterectomy. Vasodilation is expected to increase blood flow, reduce ICAP, and reduce apparent zero flow pressure. METHODS: In a randomized crossover study, the gradient between systemic arterial pressure and ICAP during carotid clamping was measured while changing between sevoflurane and propofol in 32 patients. Middle cerebral artery blood velocity, recorded by transcranial Doppler, and ICAP waveforms were analyzed to determine the apparent zero flow pressure. RESULTS: ICAP increased when changing from sevoflurane to propofol, causing the mean gradient between arterial pressure and ICAP to decrease by 10 mmHg (95% confidence interval, 6-14 mmHg; P<0.0001). Changing from propofol to sevoflurane had the opposite effect: The pressure gradient increased by 5 mmHg (95% confidence interval, 2-7 mmHg; P=0.002). Ipsilateral middle cerebral artery blood velocity decreased when changing from sevoflurane to propofol. Cerebral steal was detected in one patient after changing from propofol to sevoflurane. The apparent zero flow pressure (mean+/-SD) was 22+/-10 mmHg with sevoflurane and 30+/-14 mmHg with propofol (P<0.01). There was incomplete drug crossover due to the limited duration of carotid clamping. CONCLUSIONS: Compared with sevoflurane, ipsilateral ICAP and apparent zero flow pressure are both higher with propofol. Vasodilatation associated with sevoflurane can cause cerebral steal.

GABAA alpha6-containing receptors are selectively compromised in cerebellar granule cells of the ataxic mouse, stargazer.

Stargazer mice fail to express the gamma2 isoform of transmembrane alpha-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate (AMPA) receptor regulatory proteins that has been shown to be absolutely required for the trafficking and synaptic targeting of excitatory AMPA receptors in adult murine cerebellar granule cells. Here we show that 30 +/- 6% fewer inhibitory gamma-aminobutyric acid, type A (GABA(A)), receptors were expressed in adult stargazer cerebellum compared with controls because of a specific loss of GABA(A) receptor expression in the cerebellar granule cell layer. Radioligand binding assays allied to in situ immunogold-EM analysis and furosemide-sensitive tonic current estimates revealed that expression of the extrasynaptic (alpha6betaxdelta) alpha6-containing GABA(A) receptor were markedly and selectively reduced in stargazer. These observations were compatible with a marked reduction in expression of GABA(A) receptor alpha6, delta (mature cerebellar granule cell-specific proteins), and beta3 subunit expression in stargazer. The subunit composition of the residual alpha6-containing GABA(A) receptors was unaffected by the stargazer mutation. However, we did find evidence of an approximately 4-fold up-regulation of alpha1betadelta receptors that may compensate for the loss of alpha6-containing GABA(A) receptors. PCR analysis identified a dramatic reduction in the steady-state level of alpha6 mRNA, compatible with alpha6 being the primary target of the stargazer mutation-mediated GABA(A) receptor abnormalities. We propose that some aspects of assembly, trafficking, targeting, and/or expression of extrasynaptic alpha6-containing GABA(A) receptors in cerebellar granule cells are selectively regulated by AMPA receptor-mediated signaling.

Differential cell surface expression of GABAA receptor alpha1, alpha6, beta2 and beta3 subunits in cultured mouse cerebellar granule cells influence of cAMP-activated signalling.

In this study we have used mature, primary cultured mouse cerebellar granule cells (CGCs) to initiate our studies on the mechanisms governing neuronal trafficking of GABAA receptors (GABARs). Initially the steady-state distribution of GABAR alpha1, alpha6, beta2 and beta3 subunits between the cell surface and cell interior was quantified. Cell surface proteins were modified with a membrane-impermeable cross-linking agent, bis(sulfosuccinimidyl)suberate (BS3) or the proteolytic enzyme, chymotrypsin. The proportion of unmodified (intracellular) and modified (cell surface) subunits was quantified by immunoblotting. We found that 51% of alpha6, 74% of alpha1, and 83% of beta2/3 were expressed at the cell surface, thus identifying a sizeable intracellular pool of alpha6 in contrast to the low levels of intracellular alpha1 and beta2/3. Chronic activation of protein kinase A (PKA) in CGCs in vitro, post-transcriptionally up-regulated expression of alpha1, beta2 and beta3 but not beta6. This was paralleled by an increase in the BZ-S subtype of [3H]Ro154513 binding sites. GABAR alpha1 was increased at the cell surface and in the cell interior, beta2 was increased almost exclusively at the cell surface whilst beta3 was increased almost exclusively in the cell interior. The intracellular pool of alpha6 was not affected. Thus, GABAR subunits are subject to differentially regulated trafficking, affording yet greater scope for GABAR diversity and plasticity.

Microtubule-associated protein light chain 2 is a stargazin-AMPA receptor complex-interacting protein in vivo.

The ataxic mutant mouse stargazer is a null mutant for stargazin, a protein involved in the regulation of cell surface trafficking and synaptic targeting of AMPA receptors. The extreme C terminus of stargazin (sequence, -TTPV), confers high affinity for PDZ domain-containing proteins e.g. PSD-95. Interaction with PDZ proteins enables stargazin to fulfill its role as an AMPA receptor synaptic targeting molecule but is not essential for its ability to influence AMPA receptor trafficking to the neuronal cell surface. Using the yeast-two hybrid approach we screened for proteins that interact with the intracellular C-terminal tail of stargazin. Positive interactors included PDZ domain-containing proteins e.g. SAP97, SAP102, and PIST. Interestingly, light chain 2 of microtubule-associated protein 1 (LC2), which does not contain a PDZ domain, was also a strong interactor. This was shown to be a direct interaction that occurred upstream of the -TTPV sequence of stargazin. Immunoprecipitations of Triton X-100 soluble cerebellar extracts revealed that LC2 is pulled down not only by anti-stargazin antibodies but also anti-GluR2 antibodies suggesting that stargazin and AMPA receptor subunits associate with LC2. Immunopurified full-length, native stargazin was shown to co-associate not only with GluR2 in vivo but also with full-length, native LC2. Indeed, LC2 co-associates with stargazin when part of a tripartite complex comprising LC2-stargazin-GluR2. Since this complex was extracted using Triton X-100 and was devoid of PSD95, SAP97, and actin we postulate that LC2 is involved in trafficking of AMPA receptors in cerebellar neurons before they are anchored at the synapse.