Point of care assay for blood aripiprazole concentrations: development, validation and utility.

BACKGROUND: The antipsychotic aripiprazole is often used in the treatment of first-episode psychosis. Measuring aripiprazole blood levels provides an objective measure of treatment adherence, but this currently involves taking a venous blood sample and sending to a laboratory for analysis. AIMS: To detail the development, validation and utility of a new point of care (POC) test for finger-stick capillary blood concentrations of aripiprazole. METHOD: Analytical performance (sensitivity, precision, recovery and linearity) of the assay were established using spiked whole blood and control samples of varying aripiprazole concentration. Assay validation was performed over a 14-month period starting in July 2021. Eligible patients were asked to provide a finger-stick capillary sample in addition to their usual venous blood sample. Capillary blood samples were tested by the MyCare™ Insite POC analyser, which provided measurement of aripiprazole concentration in 6 min, and the venous blood sample was tested by the standard laboratory method. RESULTS: A total of 101 patients agreed to measurements by the two methods. Venous blood aripiprazole concentrations as assessed by the laboratory method ranged from 17 to 909 ng/mL, and from 1 to 791 ng/mL using POC testing. The correlation coefficient between the two methods (r) was 0.96 and there was minimal bias (slope 0.91, intercept 4 ng/ml). CONCLUSIONS: The MyCare Insite POC analyser is sufficiently accurate and reliable for clinical use. The availability of this technology will improve the assessment of adherence to aripiprazole and the optimising of aripiprazole dosing.

Recurrent deletions of ULK4 in schizophrenia: a gene crucial for neuritogenesis and neuronal motility.

Although many pathogenic copy number variations (CNVs) are associated with neuropsychiatric diseases, few of them have been functionally characterised. Here we report multiple schizophrenia cases with CNV abnormalities specific to unc-51-like kinase 4 (ULK4), a serine/threonine kinase gene. Deletions spanning exons 21-34 of ULK4 were present in 4 out of 3391 schizophrenia patients from the International Schizophrenia Consortium, but absent in 3181 controls. Deletions removing exons 33 and 34 of the large splice variant of ULK4 also were enriched in Icelandic schizophrenia and bipolar patients compared with 98,022 controls (P = 0.0007 for schizophrenia plus bipolar disorder). Combining the two cohorts gives a P-value less than 0.0001 for schizophrenia, or for schizophrenia plus bipolar disorder. The expression of ULK4 is neuron-specific and developmentally regulated. ULK4 modulates multiple signalling pathways that include ERK, p38, PKC and JNK, which are involved in stress responses and implicated in schizophrenia. Knockdown of ULK4 disrupts the composition of microtubules and compromises neuritogenesis and cell motility. Targeted Ulk4 deletion causes corpus callosum agenesis in mice. Our findings indicate that ULK4 is a rare susceptibility gene for schizophrenia.

Crystal structure and tartrate inhibition of Legionella pneumophila histidine acid phosphatase.

Histidine acid phosphatases (HAPs) utilize a nucleophilic histidine residue to catalyze the transfer of a phosphoryl group from phosphomonoesters to water. HAPs function as protein phosphatases and pain suppressors in mammals, are essential for Giardia lamblia excystation, and contribute to virulence of the category A pathogen Francisella tularensis. Herein we report the first crystal structure and steady-state kinetics measurements of the HAP from Legionella pneumophila (LpHAP), also known as Legionella major acid phosphatase. The structure of LpHAP complexed with the inhibitor l(+)-tartrate was determined at 2.0 Å resolution. Kinetics assays show that l(+)-tartrate is a 50-fold more potent inhibitor of LpHAP than of other HAPs. Electrostatic potential calculations provide insight into the basis for the enhanced tartrate potency: the tartrate pocket of LpHAP is more positive than other HAPs because of the absence of an ion pair partner for the second Arg of the conserved RHGXRXP HAP signature sequence. The structure also reveals that LpHAP has an atypically expansive active site entrance and lacks the nucleotide substrate base clamp found in other HAPs. These features imply that nucleoside monophosphates may not be preferred substrates. Kinetics measurements confirm that AMP is a relatively inefficient in vitro substrate of LpHAP.

Inactivation of protein tyrosine phosphatases by dietary isothiocyanates.

Isothiocyanates are bioactive dietary phytochemicals that react readily with protein thiol groups. We find that isothiocyanates are time-dependent inactivators of cysteine-dependent protein tyrosine phosphatases (PTPs). Rate constants for the inactivation of PTP1B and SHP-2 by allyl isothiocyanate and sulforaphane range from 2 to 16 M(-1)s(-1). Results in the context of PTP1B are consistent with a mechanism involving covalent, yet reversible, modification of the enzyme's active site cysteine residue.

The prevalence of premenstrual dysphoric disorder: Systematic review and meta-analysis.

BACKGROUND: Premenstrual dysphoric disorder is characterised by symptoms confined to the premenstrual phase of the menstrual cycle. Confirmed diagnosis requires prospective monitoring of symptoms over two cycles, otherwise the diagnosis is provisional. We aimed to measure the point prevalence of premenstrual dysphoric disorder. METHODS: We searched for studies of prevalence using MEDLINE, EMBASE, PsycINFO and PubMed. For each study, the total sample size and number of cases were extracted. The prevalence across studies was calculated using random effects meta-analysis with a generalised linear mixed model. Potential sources of heterogeneity were explored by meta-regression and subgroup analyses. Pre-registration was with PROSPERO (CRD42021249249). RESULTS: 44 studies with 48 independent samples met inclusion criteria, consisting of 50,659 participants. The pooled prevalence was 3.2 % (95 % confidence intervals: 1.7 %-5.9 %) for confirmed and 7.7 % (95 % confidence intervals: 5.3 %-11.0 %) for provisional diagnosis. There was high heterogeneity across all studies (I2 = 99 %). Sources of heterogeneity identified by meta-regression were continent of sample (p < 0.0001), type of sample (community-based, university, high school) (p = 0.007), risk of bias (p = 0.009), and method of diagnosis (p = 0.017). Restricting the analysis to community-based samples using confirmed diagnosis resulted in a prevalence of 1.6 % (95 % confidence intervals: 1.0 %-2.5 %), with low heterogeneity (I2 = 26 %). LIMITATIONS: A small number of included studies used full DSM criteria in community settings. CONCLUSIONS: The point prevalence of premenstrual dysphoric disorder using confirmed diagnosis is lower compared with provisional diagnosis. Studies relying on provisional diagnosis are likely to produce artificially high prevalence rates.

Translating neuroimaging findings into psychiatric practice.

Although translational medicine has become a priority for medical science, advances in neuroscience have failed to be translated for the benefit of patients. In populations at high risk of psychosis, neuroimaging could stratify those mostly likely to develop psychosis. This is an example of potentially translatable psychiatry.

A case series of premenstrual disorders presenting to the UK's National Female Hormone Clinic.

AIMS AND METHOD: We aimed to describe the clinical characteristics of female patients presenting with premenstrual disorders to a tertiary service in the UK. We conducted a retrospective case-note review of referrals to the National Female Hormone Clinic from April 2014 to August 2020. Based on clinical assessment, we determined whether the patient met criteria for premenstrual dysphoric disorder or premenstrual exacerbation of an underlying psychiatric disorder. RESULTS: Of 146 patients seen in clinic for premenstrual disorders, an ICD-10 psychiatric diagnosis was made in 130 (89.0%); a minority 16 (11.0%) did not have a psychiatric diagnosis. Following assessment, 94 patients (64.4%) met criteria for premenstrual dysphoric disorder and 67 (45.6%) had exacerbation of a psychiatric disorder. CLINICAL IMPLICATIONS: Patients presenting to this specialist service had complex psychiatric comorbidity; almost half presented with exacerbation of a psychiatric disorder.

Intermittent selective serotonin reuptake inhibitors for premenstrual syndromes: A systematic review and meta-analysis of randomised trials.

BACKGROUND: Intermittent (luteal phase) dosing of selective serotonin reuptake inhibitors is one treatment strategy for premenstrual syndromes such as premenstrual dysphoric disorder. This avoids the risk of the antidepressant withdrawal syndrome associated with long-term continuous dosing. AIMS: To compare intermittent dosing to continuous dosing in terms of efficacy and acceptability. METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PsycINFO, PubMed and CINAHL for randomised trials of intermittent compared with continuous dosing of selective serotonin reuptake inhibitors in premenstrual syndromes. We extracted response rates, dropout rates and changes in symptom scores. We used random effects meta-analyses to pool study-level data and calculated odds ratio for dichotomous data and standardised mean difference for continuous data. Risk of bias was assessed using the Cochrane risk-of-bias tool. The study was registered with PROSPERO (CRD42020224176). RESULTS: A total of 1841 references were identified, with eight studies being eligible for analysis, consisting of a total of 460 participants. All included studies provided response rates, six provided dropout rates and five provided symptom scores. There was no statistically significant differences between intermittent and continuous dosing in terms of response rate (odds ratio: 1.0, 95% confidence interval (CI): 0.23-4.31, I2 = 71%), dropout rate (odds ratio 1.26, 95% CI: 0.39-4.09, I2 = 33%) or symptom change (standardised mean difference: 0.04, 95% CI: -0.27 to 0.35, I2 = 39%). All studies had a moderate or high risk of bias. CONCLUSION: Since intermittent dosing avoids the potential for withdrawal symptoms, it should be considered more commonly in this patient population.

Systematic review of the association between adverse life events and the onset and relapse of postpartum psychosis.

Postpartum psychosis is defined as a psychotic episode occurring within 4 to 6 weeks of childbirth. While there is robust evidence that adverse life events are associated with the onset and relapse of psychosis outside the postpartum period, the extent to which these contribute to postpartum psychosis is less clear. This systematic review examined whether adverse life events are associated with an increased likelihood of developing postpartum psychosis or subsequent relapse in women diagnosed with postpartum psychosis. The following databases were searched from inception to June 2021: MEDLINE, EMBASE, PsycInfo. Study level data were extracted including setting, number of participants, type of adverse event, and differences between groups. A modified version of the Newcastle-Ottawa Quality Assessments Scale was used to assess risk of bias. In total, 1933 records were identified, of which 17 met the inclusion criteria, comprising nine case-control studies and eight cohort studies. Most studies (16/17) examined the association between adverse life events and the onset of postpartum psychosis, with only in which the outcome was relapse of psychosis. Overall, there were 63 different measures of adversity examined (most of which were examined in a single study only) and 87 associations between these measures and postpartum psychosis tested across the studies. In terms of statistically significant associations with onset/relapse of postpartum psychosis, 15 (17%) were positive (i.e., the adverse event increased the risk of onset/relapse), 4 (5%) were negative, and 68 (78%) were not statistically significant. Our review highlights the diversity of risk factors examined in this field, with few attempts at replication, hence limiting the ability to conclude that any single risk factor is robustly associated with the onset of postpartum psychosis. Further large-scale studies, that attempt to replicate earlier studies, are urgently needed to determine whether adverse life events play a role in the onset and exacerbation of postpartum psychosis. Systematic review registration: [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=260592], identifier [CRD42021260592].

Serum NOX1 and Raftlin as New Potential Biomarkers of Interest in Schizophrenia: A Preliminary Study.

Introduction: There is increasing evidence that oxidative stress (OS) and neuroinflammation play a role in the neuroprogression of schizophrenia (SCZ). Promising novel candidates which have been proposed in the search for biomarkers of psychotic illness include NADPH oxidase 1,2 (NOX1,2) and raftlin. NOX1 from the NOX family is the main source of physiological reactive oxygen species (ROS) and raftlin, the main lipid raft protein, is associated with inflammatory processes. The aim of the present study was to evaluate serum NOX1 and raftlin levels in chronic stable patients with SCZ. Methods: We measured serum NOX1 and raftlin levels from 45 clinically stable patients with SCZ and 45 healthy controls (HCs) matched for age, sex, and body-mass index. The Positive and Negative Syndrome Scale was applied to the patient group to evaluate the severity of psychotic symptoms. Results: NOX1 and raftlin levels in the patients were statistically significantly higher than the HCs (NOX1 p<0.001, raftlin p<0.001). Both parameters showed very good diagnostic performance (NOX1 AUC = 0.931, raftlin AUC = 0.915). We obtained positive and significant correlations between serum levels of both biomarkers and symptom severity. Discussion: This preliminary study indicating elevations in serum NOX1 and raftlin levels in patients with SCZ supports the importance of OS and inflammatory processes in the etiopathogenesis of the illness.

The biological buffer bicarbonate/CO2 potentiates H2O2-mediated inactivation of protein tyrosine phosphatases.

Hydrogen peroxide is a cell signaling agent that inactivates protein tyrosine phosphatases (PTPs) via oxidation of their catalytic cysteine residue. PTPs are inactivated rapidly during H(2)O(2)-mediated cellular signal transduction processes, but, paradoxically, hydrogen peroxide is a rather sluggish PTP inactivator in vitro. Here we present evidence that the biological buffer bicarbonate/CO(2) potentiates the ability of H(2)O(2) to inactivate PTPs. The results of biochemical experiments and high-resolution crystallographic analysis are consistent with a mechanism involving oxidation of the catalytic cysteine residue by peroxymonocarbonate generated via the reaction of H(2)O(2) with HCO(3)(-)/CO(2).

Crystal structure and immunogenicity of the class C acid phosphatase from Pasteurella multocida.

Pasteurella multocida is a pathogen of veterinary and medical importance. Here, we report the 1.85Å resolution crystal structure of the class C acid phosphatase from this organism (denoted rPmCCAP). The structure shows that rPmCCAP exhibits the same haloacid dehalogenase fold and dimeric assembly as the class C enzyme from Haemophilus influenzae. Formation of the dimer in solution is demonstrated using analytical ultracentrifugation. The active site is devoid of a magnesium ion due to the presence of citrate in the crystallization buffer. Absence of the metal ion minimally perturbs the active site structure, which suggests that the main role of the ion is to balance the negative charge of the substrate rather than stabilize the active site structure. The crystal lattice displays unusual crystal packing involving the C-terminal polyhistidine tag mimicking the substrate. Steady-state kinetic constants are determined for the substrates NMN, 5'-AMP, 3'-AMP, 2'-AMP, and p-nitrophenyl phosphate. The highest catalytic efficiency is observed with NMN. The production of polyclonal anti-rPmCCAP antibodies is demonstrated, and these antibodies are shown to cross-react with the H. influenzae class C phosphatase. The antibodies are used to detect PmCCAP in clinical P. multocida and Mannheimia haemolytica strains cultured from infected animals.

Expression, purification and crystallization of an atypical class C acid phosphatase from Mycoplasma bovis.

Class C acid phosphatases (CCAPs) are 25-30 kDa bacterial surface proteins that are thought to function as broad-specificity 5',3'-nucleotidases. Analysis of the newly published complete genome sequence of Mycoplasma bovis PG45 revealed a putative CCAP with a molecular weight of 49.9 kDa. The expression, purification and crystallization of this new family member are described here. Standard purification procedures involving immobilized metal-ion affinity chromatography and ion-exchange chromatography yielded highly pure and crystallizable protein. Crystals were grown in sitting drops at room temperature in the presence of PEG 3350 and HEPES buffer pH 7.5 and diffracted to 2.3 Å resolution. Analysis of diffraction data suggested a primitive monoclinic space group, with unit-cell parameters a = 78, b = 101, c = 180 Å, ß = 92°. The asymmetric unit is predicted to contain six molecules, which are likely to be arranged as three dimers.

Exacerbation of Psychosis During the Perimenstrual Phase of the Menstrual Cycle: Systematic Review and Meta-analysis.

Psychotic disorders can be exacerbated by the hormonal changes associated with childbirth, but the extent to which exacerbations occur with the menstrual cycle is unclear. We addressed this issue by conducting a systematic review. Embase, Medline, and PsychINFO databases were searched for studies that measured exacerbations of psychotic disorders in relation to the menstrual cycle. We extracted exacerbation measure, definition of menstrual cycle phase, and measurement of menstrual cycle phase. Standard incidence ratios were calculated for the perimenstrual phase based on the observed admissions during this phase divided by the expected number of admissions if the menstrual cycle had no effect. Random effects models were used to examine pooled rates of psychiatric admission in the perimenstrual phase. Nineteen studies, comprising 1193 participants were eligible for inclusion. Eleven studies examined psychiatric admission rates, 5 examined symptoms scores, 2 examined self-reported exacerbation, and 1 examined both admission rates and symptom scores. A random effects model demonstrated the rate of admissions during the perimenstrual phase was 1.48 times higher than expected (95% CI: 1.31-1.67), with no significant heterogeneity detected. Four of six symptom score studies reported perimenstrual worsening, but lack of consistency in timepoints precluded meta-analysis. Two studies examining self-reported menstrual exacerbations reported prevalences ranging from 20% to 32.4%. Psychiatric admission rates are significantly higher than expected during the perimenstrual phase. There is some evidence that a worsening of psychotic symptoms also occurs during this phase, but further research with more precise measurement of the menstrual cycle and symptomatology is required.

What Causes the Onset of Psychosis in Individuals at Clinical High Risk? A Meta-analysis of Risk and Protective Factors.

Twenty percent of individuals at clinical high risk for psychosis (CHR-P) develop the disorder within 2 years. Extensive research has explored the factors that differentiate those who develop psychosis and those who do not, but the results are conflicting. The current systematic review and meta-analysis comprehensively addresses the consistency and magnitude of evidence for non-purely genetic risk and protective factors associated with the risk of developing psychosis in CHR-P individuals. Random effects meta-analyses, standardized mean difference (SMD) and odds ratio (OR) were used, in combination with an established stratification of evidence that assesses the association of each factor and the onset of psychotic disorders (from class I, convincing evidence to class IV weak evidence), while controlling for several types of biases. A total of 128 original controlled studies relating to 26 factors were retrieved. No factors showed class I-convincing evidence. Two further factors were associated with class II-highly suggestive evidence: attenuated positive psychotic symptoms (SMD = 0.348, 95% CI: 0.280, 0.415) and global functioning (SMD = -0.291, 95% CI: -0.370, -0.211). There was class III-suggestive evidence for negative psychotic symptoms (SMD = 0.393, 95% CI: 0.317, 0.469). There was either class IV-weak or no evidence for all other factors. Our findings suggest that despite the large number of putative risk factors investigated in the literature, only attenuated positive psychotic symptoms, global functioning, and negative psychotic symptoms show suggestive evidence or greater for association with transition to psychosis. The current findings may inform the refinement of clinical prediction models and precision medicine in this field.

Characterization of a unique class C acid phosphatase from Clostridium perfringens.

Clostridium perfringens is a gram-positive anaerobe and a pathogen of medical importance. The detection of acid phosphatase activity is a powerful diagnostic indicator of the presence of C. perfringens among anaerobic isolates; however, characterization of the enzyme has not previously been reported. Provided here are details of the characterization of a soluble recombinant form of this cell-associated enzyme. The denatured enzyme was approximately 31 kDa and a homodimer in solution. It catalyzed the hydrolysis of several substrates, including para-nitrophenyl phosphate, 4-methylumbelliferyl phosphate, and 3' and 5' nucleoside monophosphates at pH 6. Calculated K(m)s ranged from 0.2 to 0.6 mM with maximum velocity ranging from 0.8 to 1.6 micromol of P(i)/s/mg. Activity was enhanced in the presence of some divalent cations but diminished in the presence of others. Wild-type enzyme was detected in all clinical C. perfringens isolates tested and found to be cell associated. The described enzyme belongs to nonspecific acid phosphatase class C but is devoid of lipid modification commonly attributed to this class.

Expression, purification and crystallization of class C acid phosphatases from Francisella tularensis and Pasteurella multocida.

Class C nonspecific acid phosphatases are bacterial enzymes that are secreted across the cytoplasmic membrane and hydrolyze a variety of phosphomonoesters at acidic pH. These enzymes are of interest for the development of improved vaccines and clinical diagnostic methods. In one case, the category A pathogen Francisella tularensis, the class C phosphatase plays a role in bacterial fitness. Here, the cloning, expression, purification and crystallization methods for the class C acid phosphatases from F. tularensis and Pasteurella multocida are reported. Crystals of the F. tularensis enzyme diffracted to 2.0 A resolution and belonged to space group C222(1), with one enzyme molecule in the asymmetric unit. Crystals of the P. multocida enzyme diffracted to 1.85 A resolution and belonged to space group C2, with three molecules in the asymmetric unit. Diffraction patterns from crystals of the P. multocida enzyme exhibited multiple interpenetrating reciprocal-space lattices, indicating epitaxial twinning. Despite this aberrance, autoindexing was robust and the data could be satisfactorily processed to 1.85 A resolution using MOSFLM and SCALA.

Moraxella catarrhalis synthesizes an autotransporter that is an acid phosphatase.

Moraxella catarrhalis O35E was shown to synthesize a 105-kDa protein that has similarity to both acid phosphatases and autotransporters. The N-terminal portion of the M. catarrhalis acid phosphatase A (MapA) was most similar (the BLAST probability score was 10(-10)) to bacterial class A nonspecific acid phosphatases. The central region of the MapA protein had similarity to passenger domains of other autotransporter proteins, whereas the C-terminal portion of MapA resembled the translocation domain of conventional autotransporters. Cloning and expression of the M. catarrhalis mapA gene in Escherichia coli confirmed the presence of acid phosphatase activity in the MapA protein. The MapA protein was shown to be localized to the outer membrane of M. catarrhalis and was not detected either in the soluble cytoplasmic fraction from disrupted M. catarrhalis cells or in the spent culture supernatant fluid from M. catarrhalis. Use of the predicted MapA translocation domain in a fusion construct with the passenger domain from another predicted M. catarrhalis autotransporter confirmed the translocation ability of this MapA domain. Inactivation of the mapA gene in M. catarrhalis strain O35E reduced the acid phosphatase activity expressed by this organism, and this mutation could be complemented in trans with the wild-type mapA gene. Nucleotide sequence analysis of the mapA gene from six M. catarrhalis strains showed that this protein was highly conserved among strains of this pathogen. Site-directed mutagenesis of a critical histidine residue (H233A) in the predicted active site of the acid phosphatase domain in MapA eliminated acid phosphatase activity in the recombinant MapA protein. This is the first description of an autotransporter protein that expresses acid phosphatase activity.