Effects of acute and sub-chronic ammonium nitrate exposure on rat liver and blood tissues

Use of fertilizers like ammonium nitrate (NH4NO3) for agricultural purposes has increasingly contaminated the ecosystem with nitrate and/or nitrites. Nitrite is a toxic substance that can cause multiple physiological effects if allowed to build up to high concentrations in animals such as methemoglobinemia. This work is concerned with the study of short term (3 days intoxication) and midterm (over 21 days) NH4NO3 exposure to wistar rats at the dose of 250 mg/Kg. Under these conditions, some hematological and biochemical parameters were affected. Methemoglobinemia, increase in serum nitrates as well as a hepatic cytotoxicity indicated by an increase in bilirubin and transaminases levels were observed

The positive impact of cisternostomy with cisternal drainage on delayed hydrocephalus after aneurysmal subarachnoid hemorrhage.

Hydrocephalus is one of the major complications of aneurysmal subarachnoid haemorrhage (aSAH). In the acute setting, an external ventricular drain (EVD) is used for early management. A cisternal drain (CD) coupled with the micro-surgical opening of basal cisterns can be an alternative when the aneurysm is clipped. Chronic hydrocephalus after aSAH is managed with ventriculo-peritoneal (VP) shunt, a procedure associated with a wide range of complications. The aim of this study is to analyse the impact of micro-surgical opening of basal cisterns coupled with CD on the incidence of VP shunt, compared to patients treated with EVD. The authors conducted a retrospective review of 89 consecutive cases of patients with aSAH treated surgically and endovascularly with either EVD or CD between January 2009 and September 2021. Patients were stratified into two groups: Group 1 included patients with EVD, Group 2 included patients with CD. Subgroup analysis with only patients treated surgically was also performed. We compared their baseline characteristics, clinical outcomes and shunting rates. There were no statistically significant differences between the two groups in terms of epidemiological characteristics, WFNS score, Fisher scale, presence of intraventricular hemorrhage (IVH), acute hydrocephalus, postoperative meningitis or of clinical outcomes at last follow-up. Cisternostomy with CD (Group 2) was associated with a statistically significant reduction in VP-shunt compared with the use of an EVD (Group 1) (9.09% vs 53.78%; p < 0.001). This finding was confirmed in our subgroup analysis, as among patients with a surgical clipping, the rate of VP shunt was 43.7% for the EVD group and 9.5% for the CD group (p = 0.02). Cisternostomy with CD may reduce the rate of shunt-dependent hydrocephalus. Cisternostomy allows the removal of subarachnoid blood, thereby reducing arachnoid inflammation and fibrosis. CD may enhance this effect, thus resulting in lower rates of chronic hydrocephalus

Non-Ischemic Cerebral Energy Dysfunction at the Early Brain Injury Phase following Aneurysmal Subarachnoid Hemorrhage.

The pathophysiology of early brain injury following aneurysmal subarachnoid hemorrhage (SAH) is still not completely understood. Using brain perfusion CT (PCT) and cerebral microdialysis (CMD), we examined whether non-ischemic cerebral energy dysfunction may be a pathogenic determinant of EBI. A total of 21 PCTs were performed (a median of 41 h from ictus onset) among a cohort of 18 comatose mechanically ventilated SAH patients (mean age 58 years, median admission WFNS score 4) who underwent CMD and brain tissue PO2 (PbtO2) monitoring. Cerebral energy dysfunction was defined as CMD episodes with lactate/pyruvate ratio (LPR) >40 and/or lactate >4 mmol/L. PCT-derived global CBF was categorized as oligemic (CBF < 28 mL/100 g/min), normal (CBF 28-65 mL/100 g/min), or hyperemic (CBF 69-85 mL/100 g/min), and was matched to CMD/PbtO2 data. Global CBF (57 ± 14 mL/100 g/min) and PbtO2 (25 ± 9 mm Hg) were within normal ranges. Episodes with cerebral energy dysfunction (n = 103 h of CMD samples, average duration 7.4 h) were frequent (66% of CMD samples) and were associated with normal or hyperemic CBF. CMD abnormalities were more pronounced in conditions of hyperemic vs. normal CBF (LPR 54 ± 12 vs. 42 ± 7, glycerol 157 ± 76 vs. 95 ± 41 µmol/L; both p < 0.01). Elevated brain LPR correlated with higher CBF (r = 0.47, p < 0.0001). Cerebral energy dysfunction is frequent at the early phase following poor-grade SAH and is associated with normal or hyperemic brain perfusion. Our data support the notion that mechanisms alternative to ischemia/hypoxia are implicated in the pathogenesis of early brain injury after SAH

Complement C5a Functions as a Master Switch for the pH Balance in Neutrophils Exerting Fundamental Immunometabolic Effects

During sepsis, excessive activation of the complement system with generation of the anaphylatoxin C5a results in profound disturbances in crucial neutrophil functions. Moreover, because neutrophil activity is highly dependent on intracellular pH (pHi), we propose a direct mechanistic link between complement activation and neutrophil pHi In this article, we demonstrate that in vitro exposure of human neutrophils to C5a significantly increased pHi by selective activation of the sodium/hydrogen exchanger. Upstream signaling of C5a-mediated intracellular alkalinization was dependent on C5aR1, intracellular calcium, protein kinase C, and calmodulin, and downstream signaling regulated the release of antibacterial myeloperoxidase and lactoferrin. Notably, the pH shift caused by C5a increased the glucose uptake and activated glycolytic flux in neutrophils, resulting in a significant release of lactate. Furthermore, C5a induced acidification of the extracellular micromilieu. In experimental murine sepsis, pHi of blood neutrophils was analogously alkalinized, which could be normalized by C5aR1 inhibition. In the clinical setting of sepsis, neutrophils from patients with septic shock likewise exhibited a significantly increased pHi These data suggest a novel role for the anaphylatoxin C5a as a master switch of the delicate pHi balance in neutrophils resulting in profound inflammatory and metabolic changes that contribute to hyperlactatemia during sepsis

Direct cochlear nerve stimulation monitoring through evoked muscle responses during retrosigmoid vestibular schwannoma resection surgery: technical note.

Cochlear nerve preservation during surgery for vestibular schwannoma (VS) may be challenging. Brainstem auditory evoked potentials and cochlear compound nerve action potentials have clearly shown their limitations in surgeries for large VSs. In this paper, the authors report their preliminary results after direct electrical intraoperative cochlear nerve stimulation and recording of the postauricular muscle response (PAMR) during resection of large VSs. The details for the electrode setup, stimulation, and recording parameters are provided. Data of patients for whom PAMR was recorded during surgery were prospectively collected and analyzed. PAMRs were recorded in all patients at the ipsilateral vertex-earlobe scalp electrode, and in 90% of the patients they were also observed in the contralateral electrode. The optimal stimulation intensity was found to be 1 mA at 1 Hz, with a good cochlear response and an absent response from other nerves. At that intensity, the ipsilateral cochlear response had an initial peak at a mean (± SEM) latency of 11.6 ± 1.5 msec with an average amplitude of 14.4 ± 5.4 µV. One patient experienced a significant improvement in his audition, while that of the other patients remained stable. PAMR monitoring may be useful in mapping the position and trajectory of the cochlear nerve to enable hearing preservation during surgery

Implementation of the Enhanced Recovery After Surgery (ERAS®) program in neurosurgery.

Over the past decade, Enhanced Recovery After Surgery (ERAS®) guidelines have been proven to simplify postoperative care and improve recovery in several surgical disciplines. The authors set out to create and launch an ERAS® program for cranial neurosurgery that meets official ERAS® Society standards. The authors summarize the successive steps taken to achieve this goal in two specific neurosurgical conditions and describe the challenges they faced. Pituitary neuroendocrine tumors (Pit-NET) resected by a transsphenoidal approach and craniosynostosis (Cs) repair were selected as appropriate targets for the implementation of ERAS® program in the Department of Neurosurgery. A multidisciplinary team with experience in managing these pathologies was created. A specialized ERAS® nurse coordinator was hired. An ERAS® certification process was performed involving 4 seminars separated by 3 active phases under the supervision of an ERAS® coach. The ERAS® Pit-NET team included 8 active members. The ERAS® Cs team included 12 active members. Through the ERAS® certification process, areas for improvement were identified, local protocols were written, and the ERAS® program was implemented. Patient-centered strategies were developed to increase compliance with the ERAS® protocols. A prospective database was designed for ongoing program evaluation. Certification was achieved in 18 months. Direct costs and time requirements are reported. Successful ERAS® certification requires a committed multidisciplinary team, an ERAS® coach, and a dedicated nurse coordinator

Surgical management of giant pituitary neuroendocrine tumors: Meta-analysis and consensus statement on behalf of the EANS skull base section.

The optimal surgical treatment for giant pituitary neuroendocrine tumors(GPitNETs) is debated. The aim of this paper is to optimize the surgical management of these patients and to provide a consensus statement on behalf of the EANS Skull Base Section. We constituted a task force belonging to the EANS skull base committee to define some principles for the management of GPitNETs. A systematic review was performed according to PRISMA guidelines to perform a meta-analysis on surgical series of GPitNETs. Weighted summary rates were obtained for the pooled extent of resection and according to the surgical technique. These data were discussed to obtain recommendations after evaluation of the selected articles and discussion among the experts. 20articles were included in our meta-analysis, for a total of 1263 patients. The endoscopic endonasal technique was used in 40.3% of cases, the microscopic endonasal approach in 34% of cases, transcranial approaches in 18.7% and combined approaches in 7% of cases. No difference in terms of gross total resection (GTR) rate was observed among the different techniques. Pooled GTR rate was 36.6%, while a near total resection (NTR) was possible in 45.2% of cases. Cavernous sinus invasion was associated with a lower GTR rate (OR: 0.061). After surgery, 35% of patients had endocrinological improvement and 75.6% had visual improvement. Recurrent tumors were reported in 10% of cases. After formal discussion in the working group, we recommend the treatment of G-PitNETs tumors with a more complex and multilobular structure in tertiary care centers. The endoscopic endonasal approach is the first option of treatment and extended approaches should be planned according to extension, morphology and consistency of the lesion. Transcranial approaches play a role in selected cases, with a multicompartmental morphology, subarachnoid invasion and extension lateral to the internal carotid artery and in the management of residual tumor apoplexy

Dieselruß: Mikrostruktur und Oxidationskinetik

The engine internal emission reduction of commercial vehicles has been very im-pressive during the last ten years. The mass related reduction of the soot emission is a result of the reduced number of particles also with regard to those 96H30)6 with the mass 7098 u. The microstructures of soot particles are related to the chemical reactivity against the oxidizing agent nitrogen dioxide, NO2 by kinetic measurements. The obtained knowl-edge will be applied in the practice for minimizing the soot particle emission of diesel en-gines and for increasing the activity of exhaust aftertreatment with PM-KATâ and GD-KAT systems. The investigation of the formation and the properties of diesel soot of advanced commercial engines is just at the beginning. We expect that the chemical properties of the surface and the microstructure of soot emitted from advanced diesel engines will re-define toxicity (threshold value of secondary genotoxicity) and relevance of physical measurement methods