Asunto(s)
Internado y Residencia , Neurocirugia , Estudiantes de Medicina , Humanos , Neurocirugia/educación , Opinión Pública , Mentores , CanadáRESUMEN
A variety of bacterial pathogenicity determinants, including the type VI secretion system and the virulence cassettes from Photorhabdus and Serratia, share an evolutionary origin with contractile-tailed myophages. The well-characterized Escherichia coli phage P2 provides an excellent system for studies related to these systems, as its protein composition appears to represent the "minimal" myophage tail. In this study, we used nuclear magnetic resonance (NMR) spectroscopy to determine the solution structure of gpX, a 68-residue tail baseplate protein. Although the sequence and structure of gpX are similar to those of LysM domains, which are a large family associated with peptidoglycan binding, we did not detect a peptidoglycan-binding activity for gpX. However, bioinformatic analysis revealed that half of all myophages, including all that possess phage T4-like baseplates, encode a tail protein with a LysM-like domain, emphasizing a widespread role for this domain in baseplate function. While phage P2 gpX comprises only a single LysM domain, many myophages display LysM domain fusions with other tail proteins, such as the DNA circulation protein found in Mu-like phages and gp53 of T4-like phages. Electron microscopy of P2 phage particles with an incorporated gpX-maltose binding protein fusion revealed that gpX is located at the top of the baseplate, near the junction of the baseplate and tail tube. gpW, the orthologue of phage T4 gp25, was also found to localize to this region. A general colocalization of LysM-like domains and gpW homologues in diverse phages is supported by our bioinformatic analysis.
Asunto(s)
Bacteriófago P2/química , Bacteriófago P2/fisiología , Escherichia coli/virología , Proteínas de la Cola de los Virus/química , Proteínas de la Cola de los Virus/metabolismo , Bacteriófago P2/ultraestructura , Glicoproteínas/química , Glicoproteínas/metabolismo , Espectroscopía de Resonancia Magnética , Microscopía Electrónica , Conformación Proteica , Virión/química , Virión/ultraestructuraRESUMEN
Background: Subsequent to a diagnosis of a brain tumor, psychological distress has been associated with negative effects on mental health as well as suicidality. The magnitude of such impact has been understudied in the literature. We conducted a systematic review to examine the impact of a brain tumor on suicidality (both ideation and attempts). Methods: In accordance with the PRISMA guidelines, we searched for relevant peer-reviewed journal articles on PubMed, Scopus, and Web of Science databases from inception to October 20, 2022. Studies investigating suicide ideation and/or attempt among patients with brain tumors were included. Results: Our search yielded 1,998 articles which were screened for eligibility. Seven studies consisting of 204,260 patients were included in the final review. Four studies comprising 203,906 patients (99.8%) reported elevated suicidal ideation and suicide attempt incidence compared with the general population. Prevalence of ideation and attempts ranged from 6.0% to 21.5% and 0.03% to 3.33%, respectively. Anxiety, depression, pain severity, physical impairment, glioblastoma diagnosis, male sex, and older age emerged as the primary risk factors associated with increased risk of suicidal ideation and attempts. Conclusion: Suicidal ideation and attempts are increased in patients and survivors of brain tumors compared to the general population. Early identification of patients exhibiting these behaviors is crucial for providing timely psychiatric support in neuro-oncological settings to mitigate potential harm. Future research is required to understand pharmacological, neurobiological, and psychiatric mechanisms that predispose brain tumor patients to suicidality.
RESUMEN
Vestibular schwannomas (VS) are the most common tumors involving the cerebellopontine angle (CPA) and the internal auditory canal (IAC). These tumors are usually slow-growing and commonly present with cranial nerve dysfunction such as hearing loss. Repeated intratumoral hemorrhage (ITH) is extremely rare with only four cases previously reported. We report the case of a 30â¯year old female with a right sided CP angle tumor who presented with vertigo and ataxia due to ITH. Her symptoms initially improved; however, three weeks later, she had acute onset of facial palsy and imaging confirmed rebleeding. Surgical pathology reported typical features of schwannoma. A literature review performed using the PubMed and EMBASE databases yielded four previous reports. A summary of these cases is presented and the features of ITH are discussed. Patients affected by repeated ITH present with sudden headache and ataxia. Rapid worsening of cranial nerve dysfunction such as hearing loss or facial nerve palsy is suggestive of ITH.
Asunto(s)
Hemorragia/complicaciones , Neurilemoma/complicaciones , Neuroma Acústico/patología , Adulto , Ataxia/etiología , Parálisis Facial/etiología , Femenino , Humanos , Neuroma Acústico/etiología , Recurrencia , Vértigo/etiologíaRESUMEN
We report a 46-year-old man who presented with a 2week history of worsening headaches and acute onset left sided hemiplegia. He had undergone a surgical resection of a sacral chordoma 13years prior, followed by adjuvant radiotherapy and chemotherapy. MRI revealed multiple enhancing lesions in the brain, and the two largest were resected. The histopathology was consistent with chordoma. Sacrococcygeal chordomas are locally invasive notochord-related sarcomas. They rarely metastasize to the brain, and only eight patients have been reported. While currently available adjuvant radiotherapy and systemic chemotherapeutic regimens can be implemented in the management of these rare patients, they have shown limited success. The newer strategies that are reported here have also been disappointing.