Viral replication relies on the host to supply nucleosides. Host enzymes involved in nucleoside biosynthesis are potential targets for antiviral development. Ribavirin (a known antiviral drug) is such an inhibitor that suppresses guanine biosynthesis; depletion of the intracellular GTP pool was shown to be the major mechanism to inhibit flavivirus. Along similar lines, inhibitors of the pyrimidine biosynthesis pathway could be targeted for potential antiviral development. Here we report on a novel antiviral compound (NITD-982) that inhibits host dihydroorotate dehydrogenase (DHODH), an enzyme required for pyrimidine biosynthesis. The inhibitor was identified through screening 1.8 million compounds using a dengue virus (DENV) infection assay. The compound contains an isoxazole-pyrazole core structure, and it inhibited DENV with a 50% effective concentration (EC 50 ) of 2.4 nM and a 50% cytotoxic concentration (CC 50 ) of >5 M. NITD-982 has a broad antiviral spectrum, inhibiting both flaviviruses and nonflaviviruses with nanomolar EC 90 s. We also show that (i) the compound inhibited the enzymatic activity of recombinant DHODH, (ii) an NITD-982 analogue directly bound to the DHODH protein, (iii) supplementing the culture medium with uridine reversed the compoundmediated antiviral activity, and (iv) DENV type 2 (DENV-2) variants resistant to brequinar (a known DHODH inhibitor) were cross resistant to NITD-982. Collectively, the results demonstrate that the compound inhibits DENV through depleting the intracellular pyrimidine pool. In contrast to the in vitro potency, the compound did not show any efficacy in the DENV-AG129 mouse model. The lack of in vivo efficacy is likely due to the exogenous uptake of pyrimidine from the diet or to a high plasma protein-binding activity of the current compound.

Current diagnoses of mood disorders are not cross validated. The aim of the current paper is to explain how machine learning techniques can be used to a) construct a model which ensembles risk/resilience (R/R), adverse outcome pathways (AOPs), staging, and the phenome of mood disorders, and b) disclose new classes based on these feature sets. This study was conducted using data of 67 healthy controls and 105 mood disordered patients. The R/R ratio, assessed as a combination of the paraoxonase 1 (PON1) gene, PON1 enzymatic activity, and early life time trauma (ELT), predicted the high-density lipoprotein cholesterol – paraoxonase 1 complex (HDL-PON1), reactive oxygen and nitrogen species (RONS), nitro-oxidative stress toxicity (NOSTOX), staging (number of depression and hypomanic episodes and suicidal attempts), and phenome (the Hamilton Depression and Anxiety scores and the Clinical Global Impression; current suicidal ideation; quality of life and disability measurements) scores. Partial Least Squares pathway analysis showed that 44.2% of the variance in the phenome was explained by ELT, RONS/NOSTOX, and staging scores. Cluster analysis conducted on all those feature sets discovered two distinct patient clusters, namely 69.5% of the patients were allocated to a class with high R/R, RONS/NOSTOX, staging, and phenome scores, and 30.5% to a class with increased staging and phenome scores. This classification cut across the bipolar (BP1/BP2) and major depression disorder classification and was more distinctive than the latter classifications. We constructed a nomothetic network model which reunited all features of mood disorders into a mechanistically transdiagnostic model.

An association between depression and altered immune and hormonal systems has been suggested by the results of many studies. In the present study we carried out immune and hormonal measurements in 40 non-medicated, ambulatory adult patients with depression determined by CID-10 criteria and compared with 34 healthy nondepressed subjects. The severity of the condition was determined with the Hamilton Depression Rating Scale. Of 40 depressed patients, 31 had very severe and 9 severe or moderate depression, 29 (72.5%) were females and 11 (27.5%) were males (2.6:1 ratio). The results revealed a significant reduction of albumin and elevation of a-1, a-2 and ß-globulins, and soluble IL-2 receptor in patients with depression compared to the values obtained for nondepressed subjects (P<0.05). The decrease lymphocyte proliferation in response to a mitogen was significantly lower in severely or moderately depressed patients when compared to control (P<0.05). These data confirm the immunological disturbance of acute phase proteins and cellular immune response in patients with depression. Other results may be explained by a variety of interacting factors such as number of patients, age, sex, and the nature, severity and/or duration of depression. Thus, the data obtained should be interpreted with caution and the precise clinical relevance of these findings requires further investigation.

Numerous interactions of the immune system with the central nervous system have been described recently. Mood and psychotic disorders, such as severe depression and schizophrenia, are both heterogeneous disorders regarding clinical symptomatology, the acuity of symptoms, the clinical course, the treatment response, and probably also the etiology. Detection of p24 RNA from Borna disease virus (BDV) by the reverse transcriptase polymerase chain reaction in patients with schizophrenia, schizoaffective disorder, and in their biological relatives was evaluated. The subjects were 27 schizophrenic and schizoaffective patients, 27 healthy controls, 20 relatives without psychiatric disease, and 24 relatives with mood disorder, who attended the Psychiatric Ambulatory of Londrina State University, Paraná, Brazil. The subjects were interviewed by structured diagnostic criteria categorized according to the Diagnostic and Statistical Manual of Mental Disorders-IV, axis I, (SCID-IV). The mean duration of illness in schizophrenic and schizoaffective patients was 15.341+/-1.494 years and the median age at onset was 22.4+/-7.371 years. There were no significant differences in gender (P=0.297), age (P=0.99), albumin (P=0.26), and body mass index (kg/m(2)) (p=0.28), among patients, controls, and relatives. Patients and biological relatives had significantly higher positive p24 RNA BDV detection than controls (P=0.04); however, the clinical significance of BDV remains to be clarified.