Aberrant gut-microbiota-immune-brain axis development in premature neonates with brain damage.

Premature infants are at substantial risk for suffering from perinatal white matter injury. Though the gut microbiota has been implicated in early-life development, a detailed understanding of the gut-microbiota-immune-brain axis in premature neonates is lacking. Here, we profiled the gut microbiota, immunological, and neurophysiological development of 60 extremely premature infants, which received standard hospital care including antibiotics and probiotics. We found that maturation of electrocortical activity is suppressed in infants with severe brain damage. This is accompanied by elevated γδ T cell levels and increased T cell secretion of vascular endothelial growth factor and reduced secretion of neuroprotectants. Notably, Klebsiella overgrowth in the gut is highly predictive for brain damage and is associated with a pro-inflammatory immunological tone. These results suggest that aberrant development of the gut-microbiota-immune-brain axis may drive or exacerbate brain injury in extremely premature neonates and represents a promising target for novel intervention strategies.

Neuroinflammation and structural injury of the fetal ovine brain following intra-amniotic Candida albicans exposure.

BACKGROUND: Intra-amniotic Candida albicans (C. Albicans) infection is associated with preterm birth and high morbidity and mortality rates. Survivors are prone to adverse neurodevelopmental outcomes. The mechanisms leading to these adverse neonatal brain outcomes remain largely unknown. To better understand the mechanisms underlying C. albicans-induced fetal brain injury, we studied immunological responses and structural changes of the fetal brain in a well-established translational ovine model of intra-amniotic C. albicans infection. In addition, we tested whether these potential adverse outcomes of the fetal brain were improved in utero by antifungal treatment with fluconazole. METHODS: Pregnant ewes received an intra-amniotic injection of 10(7) colony-forming units C. albicans or saline (controls) at 3 or 5 days before preterm delivery at 0.8 of gestation (term ~ 150 days). Fetal intra-amniotic/intra-peritoneal injections of fluconazole or saline (controls) were administered 2 days after C. albicans exposure. Post mortem analyses for fungal burden, peripheral immune activation, neuroinflammation, and white matter/neuronal injury were performed to determine the effects of intra-amniotic C. albicans and fluconazole treatment. RESULTS: Intra-amniotic exposure to C. albicans caused a severe systemic inflammatory response, illustrated by a robust increase of plasma interleukin-6 concentrations. Cerebrospinal fluid cultures were positive for C. albicans in the majority of the 3-day C. albicans-exposed animals whereas no positive cultures were present in the 5-day C. albicans-exposed and fluconazole-treated animals. Although C. albicans was not detected in the brain parenchyma, a neuroinflammatory response in the hippocampus and white matter was seen which was characterized by increased microglial and astrocyte activation. These neuroinflammatory changes were accompanied by structural white matter injury. Intra-amniotic fluconazole reduced fetal mortality but did not attenuate neuroinflammation and white matter injury. CONCLUSIONS: Intra-amniotic C. albicans exposure provoked acute systemic and neuroinflammatory responses with concomitant white matter injury. Fluconazole treatment prevented systemic inflammation without attenuating cerebral inflammation and injury.

Staphylococcus epidermidis Bacteremia Induces Brain Injury in Neonatal Mice via Toll-like Receptor 2-Dependent and -Independent Pathways.

BACKGROUND: Staphylococcus epidermidis causes late-onset sepsis in preterm infants. Staphylococcus epidermidis activates host responses in part via Toll-like receptor 2 (TLR2). Epidemiologic studies link bacteremia and neonatal brain injury, but direct evidence is lacking. METHODS: Wild-type and TLR2-deficient (TLR2-/-) mice were injected intravenously with S. epidermidis at postnatal day 1 prior to measuring plasma and brain cytokine and chemokine levels, bacterial clearance, brain caspase-3 activation, white/gray matter volume, and innate transcriptome. RESULTS: Staphylococcus epidermidis bacteremia spontaneously resolved over 24 hours without detectable bacteria in the cerebrospinal fluid (CSF). TLR2-/- mice demonstrated delayed S. epidermidis clearance from blood, spleen, and liver. Staphylococcus epidermidis increased the white blood cell count in the CSF, increased interleukin 6, interleukin 12p40, CCL2, and CXCL1 concentrations in plasma; increased the CCL2 concentration in the brain; and caused rapid (within 6 hours) TLR2-dependent brain activation of caspase-3 and TLR2-independent white matter injury. CONCLUSIONS: Staphylococcus epidermidis bacteremia, in the absence of bacterial entry into the CSF, impairs neonatal brain development. Staphylococcus epidermidis bacteremia induced both TLR2-dependent and -independent brain injury, with the latter occurring in the absence of TLR2, a condition associated with an increased bacterial burden. Our study indicates that the consequences of transient bacteremia in early life may be more severe than commonly appreciated, and our findings may inform novel approaches to reduce bacteremia-associated brain injury.

The matrix metalloproteinase inhibitor RS-130830 attenuates brain injury in experimental pneumococcal meningitis.

BACKGROUND: Pneumococcal meningitis (PM) is characterized by high mortality and morbidity including long-term neurofunctional deficits. Neuropathological correlates of these sequelae are apoptosis in the hippocampal dentate gyrus and necrosis in the cortex. Matrix metalloproteinases (MMPs) play a critical role in the pathophysiology of PM. RS-130830 (Ro-1130830, CTS-1027) is a potent partially selective inhibitor of MMPs of a second generation and has been evaluated in clinical trials as an anti-arthritis drug. It inhibits MMPs involved in acute inflammation but has low activity against MMP-1 (interstitial collagenase), MMP-7 (matrilysin) and tumour necrosis factor α converting enzyme (TACE). METHODS: A well-established infant rat model of PM was used where live Streptococcus pneumoniae were injected intracisternally and antibiotic treatment with ceftriaxone was initiated 18 h post infection (hpi). Treatment with RS-130830 (75 mg/kg bis in die (bid) i.p., n = 40) was started at 3 hpi while control littermates received the vehicle (succinylated gelatine, n = 42). RESULTS: Cortical necrosis was significantly attenuated in animals treated with RS-130830, while the extent of hippocampal apoptosis was not influenced. At 18 hpi, concentrations of interleukin (IL)-1ß and IL-10 were significantly lower in the cerebrospinal fluid of treated animals compared to controls. RS-130830 significantly reduced weight loss and leukocyte counts in the cerebrospinal fluid of survivors of PM. CONCLUSION: This study identifies MMP inhibition, specifically with RS-130830, as an efficient strategy to attenuate disease severity and cortical brain injury in PM.

White matter injury and autistic-like behavior predominantly affecting male rat offspring exposed to group B streptococcal maternal inflammation.

The impact of the group B streptococcus (GBS)-induced maternal inflammation on offspring's brain has not yet been investigated despite GBS being one of the most frequent bacteria colonizing or infecting pregnant women. According to our hypothesis GBS-induced maternal immune activation plays a role in offspring perinatal brain damage and subsequent neurodisabilities such as autism. Using a new preclinical rat model of maternal inflammation triggered by inactivated GBS, we demonstrated placental, neuropathological and behavioral impacts on offspring. GBS-exposed placentas presented cystic lesions and polymorphonuclear infiltration located within the decidual/maternal side of the placenta, contrasting with macrophagic infiltration and necrotic areas located in the labyrinth/fetal compartment of the placenta after lipopolysaccharide-induced maternal inflammation. Brain damage featured lateral ventricles widening, predominately in the male, reduction of periventricular external capsules thickness, oligodendrocyte loss, and disorganization of frontoparietal subcortical tissue with no glial proliferation. Autistic hallmarks were found in offspring exposed to GBS, namely deficits in motor behavior, social and communicative impairments, i.e. profound defects in the integration and response to both acoustic and chemical signals that are predominant modes of communication in rats. Surprisingly, only male offspring were affected by these combined autistic-like traits. Our results show for the first time that materno-fetal inflammatory response to GBS plays a role in the induction of placental and cerebral insults, remarkably recapitulating cardinal features of human autism such as gender dichotomy and neurobehavioral traits. Unlike other models of prenatal inflammatory brain damage (induced by viral/toll-like receptor 3 (TLR3) or Gram-negative/TLR4), maternal inflammation resulting from GBS/TLR2 interactions induced a distinctive pattern of chorioamnionitis and cerebral injuries. These results also provide important evidence that beyond genetic influences, modifiable environmental factors play a role in both the occurrence of autism and its gender imbalance.

[Treatment of full-thickness electric burn of skull combined with cerebral contusion and intracranial infection].

This article reports the treatment of a patient suffering from full-thickness electric burn of skull combined with cerebral contusion and intracranial infection to provide experience in treating such patients. Based on detailed analysis on patient's condition and CT results, several operations of surgery and anti-infection treatment were performed on the patient. The wounds healed 6 weeks after injury. The skull defect was repaired with three-dimensionally reconstructed titanium mesh of computer-aided design two years after wound healing. The treatment of full-thickness electric burn of skull combined with cerebral contusion was quite difficult. The timing and mode of operation were very important. Perioperative prevention and treatment of intracranial infection were essential to save the life of the patient. In the event of intracranial infection, effective systemic use of antibiotics, cerebrospinal fluid drainage, intrathecal injection of drugs, and the application of other comprehensive measures could ensure the success of treatment.

Perinatal infections, prematurity and brain injury.

PURPOSE OF REVIEW: The association between perinatal infection and brain injury is widely accepted but a cause-and-effect relationship has not yet been proven. This article summarizes available evidence and current primary publications for debate. RECENT FINDINGS: Work completed during the review period has reinforced current understanding of perinatal infection, prematurity and brain injury. In animal experiments: lipopolysaccharides have been further implicated in brain injury, not only as a cause of brain injury but also as mediators of preconditioning and protection. Recent studies suggest that cerebral injury following low-dose lipopolysaccharide administration may become compensated in adulthood. Other studies have emphasized the complexity of the response by showing that plasma cytokine levels may not reflect those in the central nervous system or inflammatory events in the brain. SUMMARY: Perinatal infection and maternofetal inflammation is strongly associated with preterm birth. Inflammation probably represents an important mechanism for cerebral damage, and both overt lesions and maldevelopment can result. Epidemiological data and multiple animal models to link infection, inflammation and brain damage exist, but proof of causation is elusive.

Chorioamnionitis and brain injury.

The limited available evidence supports a strong association of chorioamnionitis with neonatal encephalopathy and CP in the term infant. The association of chorioamnionitis with depressed Apgar scores or neonatal seizures and with CP is equivocal in the preterm infant. Different study results may be related to differences in study populations, perhaps specifically to differences in susceptibility by stages of neurologic development as well as differences in gene frequencies associated with inflammation and thrombophilia. We require further understanding of the normal roles of cytokines in brain development, pregnancy, and inflammatory homeostasis before clinical interventions directed at cytokines, their receptors, or the inflammatory process are considered.

[Clinical characteristics of burn caused by coal mine explosion].

OBJECTIVE: To investigate the characteristics of the burn injury caused by coal mine explosion so as to enhance the cure rate. METHODS: Analyse the therapeutic result after planned standard treatment of clinical patients and review historical patients. RESULTS: 1. Coal mine explosion includes two types, i.e., gas explosion and coal dust explosion. 2. This kind of burn is a combined injury with pathologic changes of burns as the main feature. Mechanical injury is the chief cause of early death. Blast injury mainly damages the lungs. The occurrence of carboxyhemoglobinemia is not often. 3. The amount of fluid infusion in the first 24 h in exudation phase is 8% less of the traditional formula. Alkaline balanced salt solution is supplied as electrolyte solution, which can provide 45% of necessary HCO3- for correction of acidosis. 4. No thorough debridement is imposed in the treatment of burn wound. Baking with electric bulb with topical SD-Ag in semi-exposure state can be used. 5. Inhalation injury chiefly occurs in upper respiratory tract. The main bacterial species causing complicated lung infection are Pseudomonas aeruginosa and Staphylococcus aureus. 6. When MSOF occurs, the most frequently involved organ and system are the kidney and respiratory system. 7. The main bacteria causing systemic invasive infection are enteric bacilli and Pseudomonas aeruginosa. Enteric bacilli infection may be enterogenic. The latter infection is chiefly the result of cross infection in hospital. CONCLUSION: The burn caused by coal mine explosion is a combined injury characterized by pathologic changes of burn as the main issue. This kind of burn has two types, i.e., gas-explosion-burn and coal-dust-explosion-burn.

Analysis of 127 war inflicted missile brain injuries sustained in north-eastern Croatia.

During the 4-year period (1991-1994) there were 127 consecutive patients with missile brain wound treated at the Division of Neurosurgery. They sustained brain injury in the region of east Slavonia, Baranya and north Bosnia, and were admitted mostly during the homeland defensive war in Croatia (1991-1992). Analysing the wounded, we divided them in two groups: "succumbed" (59 wounded) and "survivors" (68 wounded). We applied "less radical type of surgery", i.e. the patients were never re-operated only because of the retained single bone fragment. However, a retained cluster of bone fragments should be reoperated. The higher percentage of retained bone fragments (76.8%) is the result of precise visualization on the postoperative computed tomography (CT) scan. The last few cases have convinced us that the problem of the retained fragments could be solved by using an intraoprative ultrasonography. An intracranial (i.c.) infection (meningitis, abscess) occurred in 10 patients (10%), mostly among the patients who, besides the retained fragments, had cerebrospinal fluid (CSF) leak on the dehiscenced scalp wound. These cases should be reoperated soon after the CSF leak is visible on the dehiscenced wound. The overall mortality rate of 46.4% can be explained since our hospital was located close to the front-line, and some of severely wounded reached our hospital just in time to die. Excluding moribunds and those who died on the operating table (operated immediately after the admission), the mortality was 31.7%.

Posttraumatic meningitis: bacteriology, hydrocephalus, and outcome.

To investigate the conditions that have developed in the treatment of posttraumatic meningitis with the use of new antibiotics, the authors studied cases with this infection retrospectively for a period of 68 months. Among 860 patients with moderate to severe head injuries, 12 (1.39%) sustained this complication. Of these, nine patients (75%) had a demonstrable basilar skull fracture and seven (58.3%) presented obvious rhinorrhea. Of these seven, four (57.1%) were treated conservatively and three (42.8%) finally underwent surgery for dural repair. The infecting agents were Gram-positive cocci (Staphylococcus haemolyticus, Staphylococcus warneri, Staphylococcus cohnii, Staphylococcus epidermidis, and Streptococcus pneumoniae) in five patients and Gram-negative bacilli in six patients (Escherichia coli in two, Klebsiella pneumoniae in two, and Acinetobacter anitratus in two). In one patient, the culture results were negative. All Gram-negative strains appeared resistant to ampicillin and third-generation cephalosporins, but sensitive to imipenem and to the quinolone ciprofloxacin. Gram-positive strains were sensitive to vancomycin. Hydrocephalus finally developed in the two patients who had received intrathecal infusions of amikacin. No other report of the relation of intrathecal infusion of antibiotics and the development of hydrocephalus was found. All patients survived, indicating that, for the present, posttraumatic meningitis is a nonfatal complication of head injury.

[The efficacy of Augmentin in suppurative complications in neurosurgery]. / Effektivnost' Augmentina pri gnoinykh oslozhneniiakh v neirokhirurgii.

The results of clinical and laboratory studies on the use of augmentin in severe purulent complications after neurosurgical operations are presented. The laboratory studies carried out with the use of an automatic system Cobas Bact (Roch) showed that the numbers of the augmentin resistant strains of Staphylococcus and Enterobacteriaceae among the pathogens were 47 and an average of 64.5%, respectively. Gram-negative bacteria resistant to augmentin were 1.5 to 2 times less frequent than those resistant to amoxycillin. Still, they were much more frequent than those resistant to cefotaxime and ceftriaxone. Clinical efficacy of augmentin was studied in treatment of 39 patients with various affections of the brain such as tumors, trauma, vascular malformations and inflammatory processes. The postoperative complications were represented by meningitis, pneumonia, sepsis and their associations. The use of augmentin in the severe intra- and extracranial complications was favourable in 82.1% of the cases.

[Posttraumatic pyogenic and granulomatous encephalitis. An animal experimental contribution on inflammation (author's transl)]. / Die posttraumatische eitrige und granulomatöse Encephalitis. Ein tierexperimenteller Beitrag zur Entzündungslehre

The present studies were performed to elucidate the factors responsible for the relative resistance of the brain to bacterial infections. As a model, group A streptococci were used to produce an experimental brain infection in mice. Attention was focussed on the activity of brain macrophages, the function of which to date is poorly understood. The primary purpose of the experiments was to compare the types of inflammation elicited in the brain by the injection of either killed or living group A streptococci. As a result, two fundamentally different types of encephalitis were observed histologically. A granulomatous inflammation was induced by killed streptococci; when deposited in the brain by intracerebral injection, these were phagocytosed by invading mononuclear macrophages and polymorphonuclear granulocytes during the first day p.i. There was no necrosis of brain tissue excepting the stab wound at the site of injection. The number of granulocytes in the inflammatory infiltrates decreased during the first week p.i. whereas, during the same period, the number of macrophages forming granuloma-like cell accummulations increased. At the beginning of the third week a fading of the granulomatous encephalitis was observed. In contrast, living streptococci produced a pyogenic inflammation of the meninges as well as of the grey and white matter in the region of the stab wound combined with extended tissue necrosis surrounding deposits of bacteria. This pyogenic infection progressed until the end of the first week, forming a brain abscess. A phlegmonous spreading of the pyogenic inflammation predominantly in the white matter and pyocephalus internus was also observed. In contrast to the increase of mononuclear macrophages in the border zone of the abscesses, the granulocytic inflammation decreased. During the second and third weeks p.i. granulation tissue consisting of proliferating connective tissue cells, macrophages and lymphocytes replaced pyogenic necrosis. A secondary purpose was to determine the fate of living and killed streptococci within the pyogenic and granulomatous encephalitis. In these studies immunohistologic, electron microscopic, bacteriologic and serologic methods were employed in addition to the techniques already mentioned. In the majority of the experimental animals streptococci were killed by granulocytes within the first week after injection of the living bacteria. At this time, most of the streptococci were contained within granulocytes and macrophages located to the periphery of the brain abscesses. Corresponding to the granulomatous encephalitis produced by injection of killed streptococci it was possible to detect persistent cell wall material in macrophages by immunohistology. By electronmicroscopy streptococci and their cell walls were found within the phagocytic vacuoles of macrophages. During the course of degradation the group-specific cell wall carbohydrate was enzymatically converted into the group A-variant specific structure...