Correlates of substance use in a large naturalistic cohort of young people with early and emerging psychosis.

BACKGROUND: Substance use remains a barrier to recovery for young people accessing early intervention services for psychosis. While correlates of use have been explored in populations experiencing a first episode of psychosis (FEP), sample sizes have been small and less research assesses cohorts at ultrahigh risk of psychosis (UHR). METHODS: This study uses data from a naturalistic cohort including UHR and FEP participants (N = 1252) to elucidate clinical correlates of use in the past 3 months of any illicit substance, amphetamine-type stimulants (ATS), cannabis, and tobacco. Moreover, network analysis based on use of these substances and additionally alcohol, cocaine, hallucinogens, sedatives, inhalants, and opioids was completed. RESULTS: Young people with FEP used substances at significantly higher rates than those at UHR. High concurrence of use was seen between substances. In the FEP group, participants who had used any illicit substance, ATS, and/or tobacco had increased positive symptoms and decreased negative symptoms. Young people with FEP who used cannabis had increased positive symptoms. In the UHR group, participants who had used any illicit substance, ATS, and/or cannabis in the past 3 months showed decreased negative symptoms compared to those who had not. CONCLUSION: A distinct clinical picture of more florid positive symptoms and alleviated negative symptoms seen in those who use substances in the FEP group appears muted in the UHR cohort. Treating young people at UHR in early intervention services represents the earliest opportunity to address substance use early to improve outcomes.

Dual innervation of the submandibular gland by nerve to mylohyoid and chorda tympani.

The chorda tympani typically utilises the lingual nerve and submandibular ganglion to transmit parasympathetic fibres to the submandibular gland. During a routine anatomy dissection, the submandibular gland was found to be innervated by both the lingual nerve and the nerve to mylohyoid. The clinical implications of this variant dual innervation to the submandibular gland is not clear due to its rarity: however, recognising such a variation should be borne in mind during surgical intervention near the nerve to mylohyoid.

Comparison of the effect of knee synovectomy in haemophilic patients with 153Sm- and 90Y-labelled hydroxyapatite 1 year after.

To compare the use of 740 Mbq (20 mCi) of (153) Sm and 185 Mbq (5mCi) of (90) Y, both labelling hydroxyapatite (HA), for knee synovectomy in haemophilic patients, 1 year after the intervention. Thirty three men (36 knees) were studied, divided into two groups: 1 - treatment using 740 Mbq of (153) Sm-HA: 20 knees of 18 patients, with mean age of 21.4 ± 13.3 years (ranging from 7 to 56 years) and mean Pettersson score of 5.3; 2 - treatment using 185 Mbq of (90) Y-HA: 16 knees of 15 patients, with mean age of 26.3 ± 10.3 (ranging from 7 to 51 years) and mean Pettersson score of 6.3. The following criteria were adopted for the evaluation before and 1 year after synovectomy: reduction in haemarthrosis episodes and pain using a visual analogue scale, as well as improved joint mobility. The occurrence of adverse events in the treatment was also considered. The chi-square, Wilcoxon and Mann-Whitney tests were used with P ≤ 0.05 set as significant. The occurrence of haemarthrosis declined by 65.7% with the use of (153) Sm-HA and 82.6% for (90) Y-HA, with no statistical difference between the groups (P = 0.632); pain reduction was 42.5% in group 1 and 30.7% in group 2, once again with no statistical difference (P = 0.637). Improvement in joint mobility was not significant for both groups. Two cases of mild reactive synovitis were observed in group 1 and one in group 2, which cleared up without medical intervention. Although the beta energy from (90) Y is the gold standard for knee synovectomy, higher activities of (153) Sm may be used in places which have only production of this material.

Ascending palatine branch from the lingual artery with multiple other variations of the external carotid artery.

The external carotid artery (ECA) is the major blood supply for structures in the head and neck. Typically, it has 8 separate branches; but there are many anatomical variations, making it difficult to predict surgical outcomes and complications without 3-dimensional imaging. This case study focuses on a cadaver with multiple anatomical variations in the ECA, i.e., lingual, facial, occipital, ascending pharyngeal, and posterior auricular arteries, found during routine dissection of the right cadaveric neck. We also discuss the incidences of several other anatomical variations of the ECA branches and their surgical implications and potential complications.

Accessory anterior ethmoidal nerve and artery: a cadaveric case report.

The anterior ethmoidal artery (AEA) is an important surgical landmark for procedures involving the anterior cranial fossa. Many variations in the location and branching pattern of the AEA have been reported throughout the literature. These anatomical variations are important for surgeons to be familiar with as injury to the AEA can lead to massive haemorrhage, orbital haematomas, and cerebrospinal fluid rhinorrhoea. Anatomical landmarks such as the ethmoidal foramen can be used to identify the location of the AEA; however, it is also important to consider that the foramen may have variable presentations. If there is ever difficulty with identification of the AEA, surgeons should pursue a high-resolution computed tomography to minimise the risk of surgical complications. In this report, we present a rare case of a variant accessory anterior ethmoidal artery and nerve, and variations in the ethmoidal foramen found during cadaveric dissection.

The posterior cranial fossa's dura mater innervation and its clinical implication in headache: a comprehensive review.

The pathophysiology of migraines and headaches has been a point of interest in research as they affect a large subset of the population, and the exact mechanism is still unclear. There is evidence implicating the dura mater and its innervation as contributing factors, especially at the posterior cranial fossa. Many modes of innervation have been identified, including the dorsal root ganglion, superior cervical ganglion, vagus nerve, trigeminal nerve, hypoglossal nerve, and glossopharyngeal nerve. While the exact method of innervation is still under investigation, there is strong evidence suggesting that different types of headaches (migraine vs. occipital vs. cervicogenic) are due to specific nerves and inflammatory mediators that contribute to the dura mater in some way. By understanding how these innervation patterns manifest clinically, the course of treatment can be tailored based on the physiological aetiology. Here, we present a comprehensive literature review of the current research regarding the innervation of the dura mater of the posterior cranial fossa and its clinical implications.

Anisotropic contrast optical microscope.

An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 µm2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves sensitivity to a total mass required for detection by 4 orders of magnitude. We detail the design and operation principles of the anisotropic contrast optical microscope, and we present further applications to the detection of nanoparticles, to novel approaches for imaging chromatography and to new contrast modalities for observations on living cells.

Optimization of oxidized antibody labeling with lucifer yellow CH.

The oxidation of antibody carbohydrate residues is a common approach used for the site-specific immobilization or modification of antibodies. One way of following this oxidation process is to label the resulting aldehyde groups with a dye such as Lucifer yellow CH (LyCH). This study examined the optimum conditions for preparing and purifying antibody-LyCH conjugates. A 250-fold excess of LyCH reacted with antibody at pH 6.5 for two or more hours gave maximum labeling. Nonreacted LyCH could be effectively removed by passing the labeled antibody through a size exclusion column, followed by one or two dialysis cycles. The LyCH antibody conjugates were found to be stable for at least three weeks when stored in pH 7.4 phosphate buffer.

Chromatographic and electrophoretic studies of protein binding to chiral solutes.

Protein interactions are important in determining the transport, metabolism and/or activity of many chiral compounds within the body. This review examines data that have been obtained on these interactions by various chromatographic and electrophoretic methods, especially those based on either high-performance liquid chromatography or capillary electrophoresis. Zonal elution, frontal analysis and vacancy methods are each considered, as are approaches that employ either soluble or immobilized proteins. There are a variety of different items that can be learned about a solute-protein system through these techniques. This includes information on the binding constants and number of binding sites for a solute-protein system, as well as the thermodynamic parameters, rate constants, interaction forces and binding site structure for the protein and solute. Numerous examples are provided throughout this review, as taken from the literature and from work performed within the author's laboratory.

Determination of the diol content of chromatographic supports by capillary electrophoresis.

A capillary electrophoresis (CE) method was developed for determining the diol content of supports used in high-performance affinity or size exclusion chromatography. This method involved oxidizing the diol-bonded support with periodate, followed by the use of CE to separate and quantitate the iodate produced by this reaction. Both the oxidation and separation conditions were considered in optimizing this assay. The final method was performed by reacting a known amount of support with a 20-fold excess of periodate in pH 4.0, 0.5 M acetate buffer, with pyromellitic acid being used as an internal standard. After allowing 5-10 min for oxidation, the mixture was filtered and the filtrate was injected onto a 57 cm x 50 microns I.D. fused-silica capillary operated at 25 kV and containing pH 4.0, 0.5 M acetate as the running buffer. The total separation time was 5 min per run and gave a detection limit of 0.1 mM iodate (or 0.1 mumol diol groups) for a 6-nl injection of a 1-ml reaction mixture. By varying the amount the support that was assayed, this method could be used with either porous or non-porous supports. This technique showed good correlation with an iodometric titration but required much less sample and time to perform.

Role of binding capacity versus binding strength in the separation of chiral compounds on protein-based high-performance liquid chromatography columns. Interactions of D- and L-tryptophan with human serum albumin.

Frontal analysis was used to examine changes in the association constant (Ka) and moles of binding sites (mL) for D- and L-tryptophan on an immobilized HSA column under various elution conditions. Both enantiomers had single-site interactions under all conditions tested. At pH 7.0 and 25 degrees C, the strength of L-tryptophan/HSA binding was determined mostly by the change in enthalpy of the system, while D-tryptophan/HSA binding was dominated by the change in entropy. The interactions of L-tryptophan with HSA showed a large change when varying the temperature, pH, ionic strength or 1-propanol content of the mobile phase. In each case, changes in Ka accounted for most of the shifts in retention that were seen for L-tryptophan during zonal elution studies. However, mL for this compound was also affected when varying the pH and 1-propanol levels. Changes in Ka were responsible for most of the shifts in D-tryptophan retention that were seen when adjusting the mobile phase pH or ionic strength. In addition, the value of mL for D-tryptophan was affected by pH, temperature and 1-propanol levels. It was concluded that varying such chromatographic conditions can alter either the binding strength or number of binding sites for solutes injected onto immobilized protein columns.

Non-linear elution effects in split-peak chromatography. II. Role of ligand heterogeneity in solute binding to columns with adsorption-limited kinetics.

The split-peak effect is a useful phenomenon in studying the kinetic behavior of chromatographic supports. This work examined the combined role of ligand heterogeneity and non-linear elution conditions (i.e., sample load dependence) on the solute free fractions that are measured during split-peak studies. Exact expressions were derived to describe the effects of ligand heterogeneity under linear elution conditions, and simulation models were developed to specifically examine the combined effects of ligand heterogeneity and non-linear elution in systems with adsorption-limited rates for solute binding. The simulations showed that ligand heterogeneity increased the amount of free solute seen at any flow-rate or sample size, with this being most noticeable when using low flow-rates or large samples. One application in which these increases were examined in detail concerned the use of the split-peak effect for association rate constant measurements. It was found that linear extrapolation methods developed for homogeneous systems (as a correction for non-linear elution conditions) could successfully be applied to columns containing heterogeneous ligands. Columns containing immobilized protein A and/or protein G were used as experimental models to test the validity of the simulations; the behavior of these columns showed good quantitative and qualitative agreement with the predicted theoretical results.

Effect of mobile phase composition on the binding kinetics of chiral solutes on a protein-based high-performance liquid chromatography column: interactions of D- and L-tryptophan with immobilized human serum albumin.

This work examined the kinetic interactions of chiral solutes on immobilized protein columns, using the binding of D- and L-tryptophan to human serum albumin as a model. Based on band-broadening studies and previous measurements of the association equilibrium constants (Ka) for this system, estimates were obtained for the dissociation and association rate constants (kd and ka) for D- and L-tryptophan under a variety of operating conditions. The relative importance of ka versus kd in creating changes in the overall binding affinity was then considered. For example, an increase in temperature from 4 to 45 degrees C gave a large change in ka for L-tryptophan that was due both to an increase in kd and to a decrease in ka, while ka and kd for D-tryptophan showed a parallel increase that led to a much smaller temperature dependence for Ka. Similar comparisons between ka, kd and Ka were performed over a range of pH values, ionic strengths and solvent polarities. It was also possible from these studies to examine the changes in enthalpy and entropy that accompanied the formation of the activated complex between human serum albumin and each solute. The results from this work were then used to illustrate the importance of kinetics and band-broadening in protein-based chiral separations, and an example was provided showing how this type of kinetic data might be used to help optimize such separations.

Development of dihydrazide-activated silica supports for high-performance affinity chromatography.

A method of preparing dihydrazide-activated silica was developed for use in high-performance affinity chromatography (HPAC). This support was made by oxidizing diol-bonded silica and reacting it with oxalic or adipic dihydrazide. The steps involved in this synthesis were studied and confirmed by FTIR. Items considered in optimizing the preparation of the support included the amount of dihydrazide added and the reaction time or pH used. Control of dihydrazide bifunctional attachment was obtained by varying the extent of diol-bonded silica oxidation. This support was successfully used in the immobilization of oxidized antibodies, horse radish peroxidase (a glycoenzyme) and transfer RNA. In each case, data indicated that immobilization was through site specific coupling rather than non-specific adsorption. Dihydrazide-activated silica was found to be stable for 2-6 weeks after preparation when stored at 5 to 25 degrees C. The linkage between oxidized biomolecules and this support was stable for at least one month in the presence of various solvents commonly used in HPAC.

Optimization of post-column chemiluminescent detection for low-molecular-mass conjugates of acridinium esters.

In this study, various factors are examined that affect the post-column chemiluminescence detection of low-molecular-mass compounds labelled with acridinium esters, using 9-phenyl acridinium ester (PAE) as the initial model. Reaction conditions examined included the effect of hydroxide or hydrogen peroxide concentration, ionic strength and surfactant content on the degree and length of light production by the acridinium ester label. Based on these results, a system was developed for the post-column detection of acridinium ester conjugates in HPLC. The final post-column reactor had optimum conditions similar to those for a benchtop luminometer but gave light production over slightly longer periods of time and had a broader range of reagent concentrations that gave a maximum response. The detection limit of this system for PAE was 7 x 10(-19) mol per injection, with linear and dynamic ranges that extended up to 3 x 10(-15) and 3 x 10(-13) mol, respectively. Some preliminary work was conducted examining the use of this system in chromatography-based competitive binding immunoassays with a thyroxine-acridinium ester conjugate being used as the label. The estimated limit of detection was 2.5 x 10(-17) mol (or roughly 10(-12) M for a 25 microliters sample) based on the retained fraction of the conjugate.

Characterization of the protein binding of chiral drugs by high-performance affinity chromatography. Interactions of R- and S-ibuprofen with human serum albumin.

Zonal elution and high-performance affinity chromatography were used to study the different binding characteristics of R- and S-ibuprofen with the protein human serum albumin (HSA). This was done by injecting small amounts of R- and S-ibuprofen onto an immobilized HSA column in the presence of a mobile phase that contained a known concentration of R- or S-ibuprofen as a competing agent. These studies indicated that R- and S-ibuprofen had one common binding site on the immobilized HSA column. In addition, S-ibuprofen had at least one other major binding region. The association equilibrium constant for R-ibuprofen with HSA was found to be 5.3 x 10(5) M-1 at pH 6.9 and 25 degrees C. Under the same conditions, the association constants for S-ibuprofen at its two sites were 1.1 x 10(5) M-1 and 1.2 x 10(5) M-1. The S-ibuprofen sites were present in about a 1:1 ratio and appeared to exhibit some allosteric interactions at high S-ibuprofen concentrations. The chromatographic technique used in this work is a general one which can be adapted for use in studying the interactions of other chiral compounds with either HSA or additional proteins.

Antibody immobilization to high-performance liquid chromatography supports. Characterization of maximum loading capacity for intact immunoglobulin G and Fab fragments.

This study examined various factors that affect the maximum amount of intact immunoglobulin G (IgG) or Fab fragments that can be covalently immobilized to silica and other HPLC-grade supports for use in immunoaffinity chromatography or immunoextractions. Factors that were considered included the amount of surface area available for immobilization, the pore size of the support, the type of immobilization method and the nature of the support matrix. The main factor in determining the extent of immobilization was found to be the relationship between the support's surface area and the ability of the IgG or Fab fragments to reach this surface. Access to the support surface was a function of the size of the protein being immobilized and the support porosity, with maximum immobilization being obtained with supports having pore sizes of approximately 300 A for intact IgG and 100 A for Fab fragments. Some differences in the maximum level of immobilization were noted between different coupling methods. Supports like Poros and Emphaze gave similar results to those seen with HPLC-grade silica when a comparison was made between materials with comparable pore sizes. Many of the trends observed in this work for IgG and Fab fragments should apply to other proteins that are to be immobilized to HPLC supports.