Trigeminal neuropathic pain causes changes in affective processing of pain in rats.

Trigeminal neuropathic pain has been modeled in rodents through the constriction of the infraorbital nerve (CCI-ION). Sensory alterations, including spontaneous pain, and thermal and mechanical hyperalgesia are well characterized, but there is a notable lack of evidence about the affective pain component in this model. Evaluation of the emotional component of pain in rats has been proposed as a way to optimize potential translational value of non-clinical studies. In rats, 22 and 50 kHz ultrasonic vocalizations (USVs) are considered well-established measures of negative and positive emotional states, respectively. Thus, this study tested the hypothesis that trigeminal neuropathic pain would result, in addition to the sensory alterations, in a decrease of 50 kHz USV, which may be related to altered function of brain areas involved in emotional pain processing. CCI-ION surgery was performed on 60-day-old male Wistar rats. 15 days after surgery, von Frey filaments were applied to detect mechanical hyperalgesia, and USV was recorded. At the same timepoint, systemic treatment with d,l-amphetamine (1 mg/kg) allowed investigation of the involvement of the dopaminergic system in USV emission. Finally, brain tissue was collected to assess the change in tyrosine hydroxylase (TH) expression in the nucleus accumbens (NAc) and c-Fos expression in brain areas involved in emotional pain processing, including the prefrontal cortex (PFC), amygdala, and NAc. The results showed that CCI-ION rats presented mechanical hyperalgesia and a significant reduction of environmental-induced 50 kHz USV. Amphetamine caused a marked increase in 50 kHz USV emission in CCI-ION rats. In addition, TH expression was lower in constricted animals and c-Fos analysis revealed an increase in neuronal activation. Taken together, these data indicate that CCI-ION causes a reduction in the emission of environmental-induced appetitive calls concomitantly with facial mechanical hyperalgesia and that both changes may be related to a reduction in the mesolimbic dopaminergic activity.

Cell adhesion proteins in the cerebrospinal fluid of neonates prenatally exposed to Zika virus: A case-control study.

To compare cell adhesion molecules levels in cerebrospinal fluid (CSF) between Zika virus (ZIKV)-exposed neonates with/without microcephaly (cases) and controls, 16 neonates (cases), 8 (50%) with and 8 (50%) without microcephaly, who underwent lumbar puncture (LP) during the ZIKV epidemic (2015-2016) were included. All mothers reported ZIKV clinical symptoms during gestation, all neonates presented with congenital infection findings, and other congenital infections were ruled out. Fourteen control neonates underwent LP in the same laboratory (2017-2018). Five cell adhesion proteins were measured in the CSF using mass spectrometry. Neurexin-1 (3.50 [2.00-4.00] vs. 7.5 [5.00-10.25], P = 0.001), neurexin-3 (0.00 [0.00-0.00] vs. 3.00 [1.50-4.00], P = 0.001) and neural cell adhesion molecule 2 (NCAM2) (0.00 [0.00-0.75] vs. 1.00 [1.00-2.00], P = 0.001) were significantly lower in microcephalic and non-microcephalic cases than in controls. When these two sub-groups of prenatally ZIKA-exposed children were compared to controls separately, the same results were found. When cases with and without microcephaly were compared, no difference was found. Neurexin-3 (18.8% vs. 78.6%, P = 0.001) and NCAM2 (25.0% vs. 85.7%, P = 0.001) were less frequently found among the cases. A positive correlation was found between cephalic perimeter and levels of these two proteins. Neurexin-2 and neurexin-2b presented no significant differences. Levels of three cell adhesion proteins were significantly lower in CSF of neonates exposed to ZIKV before birth than in controls, irrespective of presence of congenital microcephaly. Moreover, the smaller the cephalic perimeter, the lower CSF cell adhesion protein levels. These findings suggest that low CSF levels of neurexin-1, neurexin-3 and NCAM2 may reflect the effects of ZIKV on foetal brain development.

Zika-exposed microcephalic neonates exhibit higher degree of inflammatory imbalance in cerebrospinal fluid.

Not every neonate with congenital Zika virus (ZIKV) infection (CZI) is born with microcephaly. We compared inflammation mediators in CSF (cerebrospinal fluid obtained from lumbar puncture) between ZIKV-exposed neonates with/without microcephaly (cases) and controls. In Brazil, in the same laboratory, we identified 14 ZIKV-exposed neonates during the ZIKV epidemic (2015-2016), 7(50%) with and 7(50%) without microcephaly, without any other congenital infection, and 14 neonates (2017-2018) eligible to be controls and to match cases. 29 inflammation mediators were measured using Luminex immunoassay and multidimensional analyses were employed. Neonates with ZIKV-associated microcephaly presented substantially higher degree of inflammatory perturbation, associated with uncoupled inflammatory response and decreased correlations between concentrations of inflammatory biomarkers. The groups of microcephalic and non-microcephalic ZIKV-exposed neonates were distinguished from the control group (area under curve [AUC] = 1; P < 0.0001). Between controls and those non-microcephalic exposed to ZIKV, IL-1ß, IL-3, IL-4, IL-7 and EOTAXIN were the top CSF markers. By comparing the microcephalic cases with controls, the top discriminant scores were for IL-1ß, IL-3, EOTAXIN and IL-12p70. The degree of inflammatory imbalance may be associated with microcephaly in CZI and it may aid additional investigations in experimental pre-clinical models testing immune modulators in preventing extensive damage of the Central Nervous System.

Evolution of cytokines/chemokines in cases with community-acquired pneumonia and distinct etiologies.

AIM: To compare the systemic cytokines/chemokines levels over time during the evolution of children hospitalized with community-acquired pneumonia (CAP) with and without pneumococcal infection. METHODS: Children less than 5-years-old hospitalized with CAP were prospectively investigated in Salvador, Brazil. Clinical data and biological samples were collected to investigate 20 etiological agents and to determine serum cytokines/chemokines levels on admission and 2 to 4 weeks later. Cases with pneumococcal infection received this diagnosis irrespective of also having other etiologies. RESULTS: A total of 277 patients were enrolled, however, serum sample was unavailable for cytokine measurement upon admission (n = 61) or upon follow-up visit (n = 36), etiology was undetected (n = 50) and one patient did not attend the follow-up visit. Therefore, this study group comprised of 129 cases with established etiology. The median (interquartile range) age and sampling interval was 18 (9-27) months and 18 (16-21) days, respectively. Established etiology was viral (52.0%), viral-bacterial (30.2%), and bacterial (17.8%). Pneumococcal infection was found in 31 (24.0%) patients. Overall, median interleukin-6 (IL-6; 10.6 [4.7-30.6] vs 21.0 [20.2-21.7]; P = .03), IL-10 (3.5 [3.1-4.5] vs 20.1 [19.8-20.4]; P < .001), and CCL2 (19.3 [12.4-23.2] vs 94.0 [67.2-117.8]; P < .001) were significantly higher in convalescent serum samples, whereas median CXCL10 (83.6 [36.4-182.9] vs 14.6 [0-116.6]; P < .001) was lower. Acute vs convalescent levels evolution of IL-10, CCL2, and CXCL10 did not differ among patients with or without pneumococcal infection. However, IL-6 decreased (27.8 [12.3-48.6] vs 20.8 [20.2-22.6]; P = .1) in patients with pneumococcal infection and increased (9.0 [4.2-22.6] vs 21.0 [20.2-21.7]; P = .001) in patients without it. CONCLUSION: The marked increase of IL-6 serum levels during the acute phase makes it a potential biomarker of pneumococcal infection among children with CAP.

Cerebrospinal fluid immunoglobulins are increased in neonates exposed to Zika virus during foetal life.

OBJECTIVE: To compare immunoglobulin levels in cerebrospinal fluid (CSF) of neonates exposed to Zika virus (ZIKV) during foetal life (cases) with levels in CSF of control neonates. METHODS: We identified 16 neonates who underwent lumbar puncture (LP), during the ZIKV epidemic (December/2015 to March/2016) whose mothers reported ZIKV clinical symptoms during gestation (cases). Congenital microcephaly was defined as head circumference ≤31.9 cm (boys) and ≤31.5 cm (girls) for term neonates, or ≤2 standard deviations below the mean for premature (<37 weeks) neonates. Subsequently, we identified neonates who underwent LP in the same lab and fulfilled criteria to be controls: age ≤4 days, CSF white blood cell count ≤8/mm3, CSF protein ≤132 mg/dL, CSF red blood cell count ≤1,000/mm3, neither central nervous system illness, nor congenital infection, nor microcephaly. CSF immunoglobulin concentrations were measured by mass spectrometry. RESULTS: 13 controls were included. IgM, IgA, IgG, IgK, and IgL were significantly higher among cases (p < 0.001). Eight (50%) ZIKV exposed infants had congenital microcephaly. These showed the strongest immunoglobulin elevation of the IgM and IgA classes. CONCLUSION: Neonates exposed to ZIKV infection during gestation present with elevated distinct immunoglobulins in CSF, both in cases that developed microcephaly and in cases that did not.