The tetramer of p53 in the absence of DNA forms a relaxed quaternary state.

p53 is a tetrameric multidomain protein that triggers the anticancer cellular response to stress. We have calculated a three-dimensional reconstruction of full-length human p53 in the absence of DNA using single-particle electron microscopy. The reconstruction of DNA-free full-length p53 shows a square-shaped structure with four distinct domains and a hollow center. In comparison with the known compacted DNA-bound full-length p53 structures, the DNA-free p53 tetramer adopts a relaxed conformation with separated monomers and oligomerization interfaces different from those of the DNA-bound conformation.

Case Report: Three Case Reports of Rapidly Progressive Dementias and Narrative Review.

Rapidly progressive dementia (RPD) is a heterogeneous group of diseases characterized by cognitive impairment and other neurological disorders developed in a short span of fewer than 2 years. Currently viewed as new and infrequent entities, most medical personnel have little understanding of it. Nevertheless, they significantly compromise many patients' quality of life. Here, we drive 3 clinical cases that evolve as RPD with different etiologies. Case 1: 70-year-old woman presented to the emergency with neuropsychiatric syndrome for 18 days. The researchers identified inflammatory cerebrospinal fluid (CSF), protein 14-3-3-positive T-tau protein, MRI: T2 and FLAIR hyperintensities in bilateral caudate nuclei with diffusion restriction, EEG shows a generalized periodic pattern with triphasic wave morphology. Case 2: 29-year-old man with cognitive impairment and faciobrachial dystonia seizure. The diagnosis was confirmed by achieving elevated antibodies against voltage-gated potassium channels. Case 3: A 49-year-old woman with encephalopathy and myoclonic seizures; EEG and MRI showed subtle changes. The patient also had a normal CSF but a positive CBA serologic NMDA-R antibody test. We described fundamental aspects of RPD to allow made differential diagnoses in patients with cognitive impairment and encephalopathy. Establishing an early and accurate diagnosis can benefit patients with RPD etiologies that are treatable and even reversible, decreasing in morbidity and mortality.

Neuropsychiatric Alterations in a Patient Diagnosed with Advanced Korsakoff's Syndrome: Clinical Case of Low Incidence and Prevalence in Colombia.

Korsakoff's syndrome (KS) is an insidious and progressive neuropsychiatric disorder that affects specific neurocognitive functioning, especially in tasks that require sustained attention, memory, executive functions, and visuospatial functioning. Usually, this disease generates neuropsychiatric complications that worsen the quality of life (QOL) of patients in the medium term. We present a case of a 63-year-old male who presented with a diagnosis of advanced Korsakoff's syndrome and has a clinical history of recurrent memory loss and a history of alcohol abuse. The patient showed difficulty manipulating immediate information, associated with a possible frontal lobe dysfunction, and inability to remember material given through the auditory pathway. The patient showed a psychiatric clinical picture which is constantly worsening his and his immediate caregiver's QOL. The data obtained demonstrate that the patient presents a progressive cognitive impairment, which in the short term is correlated with Korsakoff-type dementia. It is suggested to carry out functional neurorehabilitation plans aimed at improving the QOL of the patient, his immediate caregiver, and future people with this type of diagnosis.