Search

For close to 2 years, we have witnessed the impacts of the SARS-CoV-2 pandemic on research at several different levels. Among the list, limited access to laboratory-based training for undergraduate students prevented this cohort from gaining exposure to the realities of a research laboratory at a critical time in training when they may have found motivation in this area as a career. COVID exposed a weakness in our training pipeline; an extreme dependency on face-to-face training that threatened to create a void in the research talent needed to replenish the scientific community every year. In the classroom, we witnessed a revolution of e-learning based approaches that could be rapidly implemented based on existing footprints. Out of necessity, our laboratory developed and implemented an e-learning model of an undergraduate peer mentor network that provides a knowledge and experience exchange platform between students with different levels of research experience. Implementation of the platform was to aid students with gaining knowledge in multiple aspects of scientific research and hands-on work in a research laboratory. The collaboration between the students of the network was aimed at not only advancing the theoretical and practical research experience, but also at developing feedback implementation and practicing "soft skills" critical for teamwork and leadership. Herein, we present an overview of the model along with survey responses of the students participating in the peer mentor network. We have found that peer delivery of practical benchwork both via scientific presentations and visualized experiments, reduced the time of training and the amount of staff assistance needed when students returned to the bench. Furthermore, this model accelerated student independence in laboratory work and increased research interest overall. In summary, the model of a peer mentor network has the potential to serve as a training platform and as a customized tool, supplementing research laboratory training at the undergraduate level beyond the pandemic., (© 2023 The Authors. Biochemistry and Molecular Biology Education published by Wiley Periodicals LLC on behalf of International Union of Biochemistry and Molecular Biology.)

Cerebral blood flow was measured, under controlled conditions of stable ventilation and PaCO2, in 11 patients suffering from cerebro-vascular lesions. Comparing the results under N2O-enflurane 1% anesthesia with those under N2O-fentanyl anesthesia shows an average 8.4% decrease of blood flow. In 5 cases, a third measurement was performed under N2O-enflurane 2% anesthesia. This caused an average 8.5% complementary decrease. Whereas most inhalational anesthetic agents produce an increase of cerebral blood flow, this is not observed with enflurane, the tendency rather being towards a decrease.

The authors analyse 14 cases of aneurysm occurring at the point of bifurcation of the internal carotid artery into the middle and anterior cerebral arteries. Distinguishing features of this aneurysm are often its fairly large size and extensive implantation on the artery. Clinical symptoms are not specific but various neurological signs are frequent. The bifurcation of the carotid artery is not always readily visible; oblique views and angiotomography are often necessary. Owing to the usual severity of the natural evolution of this type of aneurysm (death in six out of eight cases), surgical treatment is advisable. Ligation of the carotid artery is disadvised because of the unpredictable nature of its results (further fatal haemorrhage in one out of three cases).

In case of cranial trauma, early respiratory troubles either of central or peripheral origin often accelerate the deterioration of the neurological situation. The different values of PCO2, PO2, pH and alcaline reserve measured on samples of CSF in comatose patients prove the central acidosis related to metabolic and vascular disorders in the damaged areas. Our results confirm the correlation between the importance of this disturbances and the severity of the trauma. It is thus necessary to insure patients of satisfactory respiration conditions. The tracheobronchial cleansing is applicable to intubated or tracheotomized patients by an instillation of 5ml of simple or bicarbonated physiological serum 4 to 6 times a day, followed by repeated aspirations and associated to a preventive endotracheal instillation of 80 mg of Gentamycin 4 times a day. Moreover we use controlled respiration which does not modify the gazometric parameters in the CSF but which assures patients a normoxia and moderate hypocapnia with a decrease of intracranial hypertension. Treatment by controlled hyperventilation must be precocious, because the recuperation at the level of the damaged zones is very slow.

In patients operated for cerebral aneurysm or angioma, the same basic method of anesthesia has been used. Premedication consisted of Thalamonal or diazepam. After induction with thiopentone, curarisation with pancuronium and tracheal intubation, anesthesia was maintained with N2O 70%, O2 30% and enflurane 1%. Small doses of fentanyl or Thalamonal were given at the beginning of anesthesia, but no more within 30 minutes before starting controlled hypotension. Adjuvant drugs and methods to reduce intracranial pressure were also used, such as dexamethasone, mannitol and cerebro-spinal fluid subtraction. The approach and dissection of the vascular lesion was done under controlled hypotension with sodium nitroprusside 0.01% solution. The mean dose of sodium nitroprusside to maintain a mean blood pressure at about 50 Torr was 1.37 mcg/kg/min.

In neuro-anaesthesia, anaesthetic agents must be in accordance with certain criteria necessary to the preservation of the integrity of the brain. Therefore it was in such a perspective that we re-appraised the effects of enflurane upon cortical irritability, metabolism, cerebral blood flow and intracranial pressure. We reached the following conclusions: in normocapnia, and with optimal clinical concentrations, this drug remains the best anaesthetic agent since it has no harmful effect either upon metabolism or upon cerebral blood flow. However, in hypertensive cerebral lesions, caution is called for an it seems advisable to combine Enflurane with mild doses of fentanyl. Finally, anaesthesia with enflurane is followed by a rapid and smooth return to consciousness, a valuable factor in neurosurgery where post-operative neurological watching matters very much.

Head trauma is a possible cause of E.C.G. modifications originating in the brain and unresponsive to pure symptomatic cardial therapy. On the other hand, these perturbations react in a favourable way to treatment aimed at protecting the heart against descending nociceptive influx caused by brain injury. This report shows the results of a retrospective electrographic study of 220 unoperated patients with head injuries aged 15 to 30 years. A correlation is established between E.C.G. findings and depth of coma. The authors discuss their findings and suggest an etiologic pathology based on clinical and experimental factors.

The age factor is analysed for the operative indication in old patients. For the authors, operative indications are depended of mental and general status, clinical grade (I or II), localization and anatomical conformation of the aneurysm. The operation is performed only if the patient is asymptomatic or three weeks after the onset of the subarachnoid hemorrage. The peroperative hypotension is prohibited.