Dysbiosis of a microbiota-immune metasystem in critical illness is associated with nosocomial infections.

Critically ill patients in intensive care units experience profound alterations of their gut microbiota that have been linked to a high risk of hospital-acquired (nosocomial) infections and adverse outcomes through unclear mechanisms. Abundant mouse and limited human data suggest that the gut microbiota can contribute to maintenance of systemic immune homeostasis, and that intestinal dysbiosis may lead to defects in immune defense against infections. Here we use integrated systems-level analyses of fecal microbiota dynamics in rectal swabs and single-cell profiling of systemic immune and inflammatory responses in a prospective longitudinal cohort study of critically ill patients to show that the gut microbiota and systemic immunity function as an integrated metasystem, where intestinal dysbiosis is coupled to impaired host defense and increased frequency of nosocomial infections. Longitudinal microbiota analysis by 16s rRNA gene sequencing of rectal swabs and single-cell profiling of blood using mass cytometry revealed that microbiota and immune dynamics during acute critical illness were highly interconnected and dominated by Enterobacteriaceae enrichment, dysregulated myeloid cell responses and amplified systemic inflammation, with a lesser impact on adaptive mechanisms of host defense. Intestinal Enterobacteriaceae enrichment was coupled with impaired innate antimicrobial effector responses, including hypofunctional and immature neutrophils and was associated with an increased risk of infections by various bacterial and fungal pathogens. Collectively, our findings suggest that dysbiosis of an interconnected metasystem between the gut microbiota and systemic immune response may drive impaired host defense and susceptibility to nosocomial infections in critical illness.

Development of a Bedside Tool to Predict the Diagnosis of Cerebral Palsy in Term-Born Neonates.

Importance: Cerebral palsy (CP) is the most common abnormality of motor development and causes lifelong impairment. Early diagnosis and therapy can improve outcomes, but early identification of infants at risk remains challenging. Objective: To develop a CP prognostic tool that can be applied to all term neonates to identify those at increased risk of developing CP. Design, Setting, and Participants: This case-control study used data from the Canadian Cerebral Palsy Registry (data collected from January 2003 to December 2019) for children with CP and the Alberta Pregnancy Outcomes and Nutrition study (mothers enrolled from May 2009 to September 2012; data extracted in 2020) for controls. There were 2771 children with CP and 2131 controls evaluated; 941 and 144, respectively, were removed for gestational age less than 37 weeks at birth, 565 with CP removed for incomplete data, and 2 controls removed for a diagnosis of CP. Data were analyzed from April to August 2022. Exposures: Potential risk factors were selected a priori based on the literature, including maternal, intrapartum, and infant characteristics. Main Outcomes and Measures: Diagnosis of CP, defined as a disorder of motor function due to a nonprogressive brain abnormality before age 1 year and classified by Gross Motor Function Classification System levels I to V. Results: Of 3250 included individuals, 1752 (53.9%) were male, and the median (IQR) gestational age at birth was 39 (38-40) weeks. Encephalopathy was present in 335 of 1184 infants with CP (28%) and 0 controls. The final prediction model included 12 variables and correctly classified 75% of infants, with a sensitivity of 56% (95% CI, 52-60) and specificity of 82% (95% CI, 81-84). The C statistic was 0.74 (95% CI, 71-76). Risk factors were found to be additive. A proposed threshold for screening is probability greater than 0.3, with a sensitivity of 65% (95% CI, 61-68) and specificity of 71% (95% CI, 69-73). The prognostic tool identified 2.4-fold more children with CP than would have presented with encephalopathy (odds ratio, 13.8; 95% CI, 8.87-22.65; P < .001). Conclusions and Relevance: In this case-control study, a prognostic model using 12 clinical variables improved the prediction of CP compared with clinical presentation with encephalopathy. This tool can be applied to all term newborns to help select infants for closer surveillance or further diagnostic tests, which could improve outcomes through early intervention.

Antenatal diagnosis of fetal intraventricular hemorrhage: systematic review and meta-analysis.

AIM: To determine how the severity of antenatally diagnosed germinal matrix-intraventricular hemorrhage (GMH-IVH) relates to morbidity and mortality, and to explore potential risk factors. METHOD: We conducted a systematic review and individual patient data meta-analysis of antenatally diagnosed fetal GMH-IVH. The primary outcomes were mortality and morbidity. Potential associations with clinical factors during pregnancy were explored. Analysis employed Fisher's exact test and logistic regression. RESULTS: We included 240 cases from 80 studies. Presence of venous infarction was associated with mortality (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.4-13.25), motor impairment (OR 103.2, 95% CI 8.6-1238), epilepsy (OR 6.46, 95% CI 2.64-16.06), and developmental delay (OR 8.55, 95% CI 2.12-48.79). Shunt placement was associated with gestational age at GMH-IVH diagnosis and in utero progression. Many cases had uncomplicated pregnancies but possible co-occurring conditions included twin gestation, small for gestational age, and congenital anomalies. INTERPRETATION: Severity of fetal GMH-IVH, specifically venous infarction, is associated with overall mortality and morbidity. Risk factors for fetal GMH-IVH are poorly understood and controlled studies are required. WHAT THIS PAPER ADDS: Preterm germinal matrix-intraventricular hemorrhage (GMH-IVH) grading can be applied to fetuses. Many fetal germinal matrix hemorrhages occur in otherwise typical pregnancies. Half of fetuses with post-hemorrhagic ventricular dilatation receive a shunt after delivery. Fetuses with grade I or II GMH-IVH have few sequelae. Fetuses with periventricular hemorrhagic infarction have a high burden of motor impairment.

Significant Dose-Response between Exercise Adherence and Hemoglobin A1c Change.

INTRODUCTION: The Diabetes Aerobic and Resistance Exercise trial found that aerobic training and resistance training alone each reduced hemoglobin A1c (HbA1c) compared with nonexercising controls, and combined aerobic and resistance training caused greater HbA1c reduction than either training type alone. Our objective was to determine whether a dose-response relationship existed between frequency of exercise training and HbA1c change, and whether this varied by exercise modality or participant characteristics. METHODS: Post hoc analysis of data from 185 Diabetes Aerobic and Resistance Exercise trial participants with type 2 diabetes randomized to aerobic, resistance or combined training thrice weekly. Dose-response relationships between adherence (percent of prescribed training sessions completed) and HbA1c change were assessed with linear regression. RESULTS: Median overall adherence was 84.9% (interquartile range, 74.4%-93.6%). Higher exercise adherence was associated with greater HbA1c reduction; a 20% increase in adherence (e.g., an additional two sessions per month) was associated with a 0.15% (2 mmol·mol) decrease in HbA1c (ß = -0.0076, R = -0.170, P = 0.021). Significant dose-response relationships were identified for aerobic (ß = -0.0142, R = -0.313, P = 0.016) and combined training (ß = -0.0109, R = -0.259, P = 0.041), but not resistance training (ß = 0.0068, R = 0.153, P = 0.233). Dose-response relationships in all training groups combined were significant in subgroups younger than 55 yr (ß = -0.0113, R = -0.286, P = 0.005), males (ß = -0.0123, R = -0.234, P = 0.010), and baseline HbA1c ≥7.5% (58 mmol·mol) (ß = -0.013, R = -0.263, P = 0.011). CONCLUSIONS: There was a dose-response relationship between adherence to prescribed exercise and HbA1c reduction suggesting that glycemic control is improved more in individuals with type 2 diabetes with a higher training volume. Dose-response relationships existed for aerobic and combined training but not resistance training. These findings support aerobic and combined exercise prescriptions outlined in clinical practice guidelines.

Evolution of a Pediatric Primary Cerebral ALK-1-Positive Anaplastic Large Cell Lymphoma on Serial MRI.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is a rare central nervous system tumor, especially in the pediatric population. There are fewer than 20 described cases of pediatric primary central nervous system anaplastic large cell lymphoma. The child described in our case report demonstrated a dramatic evolution of this tumor in the first 4 weeks on serial imaging. METHODS: Serial MRI imaging was performed followed by biopsy and chemotherapy. RESULTS: Initial imaging revealed a T2 hyperintense lesion in the frontal lobe with abnormally enhancing sulci and minimal surrounding edema and diffusion restriction. Serial imaging revealed progressive increase in the degree of gadolinium enhancement, and the hyperintense T2 edema progressed markedly to exert mass effect. The lesion itself grew marginally. Biopsy revealed an anaplastic large cell lymphoma, only described in 14 previous pediatric patient case reports. The patient was successfully treated with chemotherapy and autologous stem cell transplant. CONCLUSIONS: Our case demonstrates the rapidity with which a PCNSL lesion can develop, and the evolution of the imaging characteristics prior to definitive diagnosis and treatment. Serial imaging by MRI may help differentiate the behavior of a PCNSL from other imitating lesions.

Endogenous extracellular serotonin modulates the spinal locomotor network of the neonatal mouse.

Serotonin (5-HT) can potently activate and modulate spinal locomotor circuits in a variety of species. Many of these findings have been obtained by applying serotonin exogenously to the isolated spinal cord of in vitro preparations, which has the drawback of indiscriminately activating extrasynaptic receptors and neurons. To investigate the role of endogenously released serotonin in modulating locomotor networks, the selective serotonin reuptake inhibitor citalopram was used. Fictive locomotion was elicited by either electrical stimulation of the brainstem or the sacral 4 (S4) dorsal root. The addition of 20 microm of citalopram caudal to thoracic segment 5 (T5) had an overall inhibitory effect on the lumbar central pattern generator (CPG). Left-right and flexor-extensor coupling were significantly decreased, and there was also a phase shift in the flexor-extensor relationship. In addition, there was a significant decrease in burst amplitude. These effects were observed during both afferent and brainstem evoked fictive locomotion. When citalopram was added in the presence of 5-HT(1A) and 5-HT(1B) antagonists, the inhibitory effects were largely reversed. The remaining excitatory effects were mediated by 5-HT(7) and 5-HT(2) receptors. These results suggest that endogenous 5-HT release can modulate locomotor-like activity early in neonatal development.

Interaction between developing spinal locomotor networks in the neonatal mouse.

At birth, thoracosacral spinal cord networks in mouse can produce a coordinated locomotor-like pattern. In contrast, less is known about the cervicothoracic networks that generate forelimb locomotion. Here we show that cervical networks can produce coordinated rhythmic patterns in the brain stem-spinal cord preparation of the mouse. Segmentally the C5 and C8 neurograms were each found to be alternating left-right, and the ipsilateral C5 and C8 neurograms also alternated. Collectively these patterns were suggestive of locomotor-like activity. This pattern was not dependent on the presence of thoracosacral segments because they could be evoked following a complete transection of the spinal cord at T5. We next demonstrated that activation of thoracosacral networks either pharmacologically or by stimulation of sacrocaudal afferents could produce rhythmic activity within the C5 and C8 neurograms. On the other hand, pharmacological activation of cervical networks did not evoke alternating cervical rhythmic activity either in isolated cervicothoracic or -sacral preparations. Under these conditions, we found that activation of cervicothoracic networks could alter the timing of thoracosacral locomotor-like patterns. When thoracosacral networks were not activated pharmacologically but received rhythmic drive from cervicothoracic networks, a pattern of slow bursts with superimposed fast synchronous oscillations became the dominant lumbar neurogram pattern. Our data suggest that in neonatal mice the cervical CPG is capable of producing coordinated rhythmic patterns in the absence of input from lumbar segments, but caudorostral drive contributes to cervical patterns and rhythm stability.