The role of Zn ions in the interaction between SARS-CoV-2 orf7a protein and BST2/tetherin

In this paper, we provide evidence that Zn 2 + ions play a role in the SARS-CoV-2 virus strategy to escape the immune response mediated by the BST2-tetherin host protein. This conclusion is based on sequence analysis and molecular dynamics simulations as well as X-ray absorption experiments [1].

The Lung Microbiota and Lung Cancer: A Growing Relationship

Simple Summary

In the past few years, the microbiota has emerged as a major player in cancer management. The efficacy of chemotherapy or immunotherapy may be influenced by the concomitant use of antibiotics before, during, or shortly after treatment with immune checkpoint inhibitors. Despite this, the mechanism linking the microbiota, host immunity, and malignancies are not clear, and the role of microbiota manipulation and analyses in cancer management is underway. In this manuscript, we discuss the role of the microbiota in the initiation, progression, and treatment outcomes of lung cancer.

Abstract

The lung is home to a dynamic microbial population crucial to modulating immune balance. Interest in the role of the lung microbiota in disease pathogenesis and treatment has exponentially increased. In lung cancer, early studies suggested an important role of dysbiosis in tumor initiation and progression. These results have helped accelerate research into the lung microbiota as a potential diagnostic marker and therapeutic target. Microbiota signatures could represent diagnostic biomarkers of early-stage disease. Lung microbiota research is in its infancy with a limited number of studies and only single-center studies with a significant methodological variation. Large, multicenter longitudinal studies are needed to establish the clinical potential of this exciting field.

Metal Ion Binding in Wild-Type and Mutated Frataxin: A Stability Study

This work studies the stability of wild-type frataxin and some of its variants found in cancer tissues upon Co2+ binding. Although the physiologically involved metal ion in the frataxin enzymatic activity is Fe2+, as it is customarily done, Co2+ is most often used in experiments because Fe2+ is extremely unstable owing to the fast oxidation reaction Fe2+ → Fe3+. Protein stability is monitored following the conformational changes induced by Co2+ binding as measured by circular dichroism, fluorescence spectroscopy, and melting temperature measurements. The stability ranking among the wild-type frataxin and its variants obtained in this way is confirmed by a detailed comparative analysis of the XAS spectra of the metal-protein complex at the Co K-edge. In particular, a fit to the EXAFS region of the spectrum allows positively identifying the frataxin acidic ridge as the most likely location of the metal-binding sites. Furthermore, we can explain the surprising feature emerging from a detailed analysis of the XANES region of the spectrum, showing that the longer 81-210 frataxin fragment has a smaller propensity for Co2+ binding than the shorter 90-210 one. This fact is explained by the peculiar role of the N-terminal disordered tail in modulating the protein ability to interact with the metal.

Evaluation of Discomfort in Nasopharyngeal Swab Specimen Collection for SARS-CoV-2 Diagnosis

Background

The rapid spread of COVID-19 worldwide has impo-sed the need to identify a test that quickly recognizes affected subjects, both symptomatic and asymptomatic. The most reliable option has been proven to be the RT-PCR, which allows to detect virus RNA on a specimen from a high viral load site, such as nasopharynx. Nasopha-ryngeal sample collection is possible by means of a nasopharyngeal swab (NPS) and is a practical and relatively non-invasive technique, but rather bothersome for the recipient.

Aim

The aim of the present study is to evaluate the discomfort evoked during NPS.

Materials and Methods

We surveyed 429 patients receiving NPS before hospitalization or other procedures non related to COVID-19. For each one we noted the discomfort level felt during the swab using a 11-point numeric rating scale (NRS) for pain and the total time needed for the procedure to be taken. Sex, age, smoking status and positive history of previous swab have been taken into account.

Results

We found that, among the variables, sex had a statistically significant impact on the perceived discomfort of nasal swab, with females experiencing slightly more discomfort.

Conclusions

NPS is largely a none-to-minimum discomfort in-ducing procedure. The differences in perceived discomfort could be explained based on anatomical features, and should remark the need for a tailored and anatomy-oriented approach in each patient.

Pro-BNP as a biomarker of asymptomatic clozapine-related heart dysfunction: Possible usefulness for clozapine management

Cardiovascular clozapine-related side effects such as tachycardia and orthostatic hypotension are well recognized, but are rarely clinically important. However, the increasing number of life-threatening drug-related complications are giving rise to concerns about cardiac adverse reactions (myocarditis, cardiomyopathy, pericarditis and heart failure). The diagnosis is usually made considering patient's symptoms, such as tachycardia, slightly increased body temperature, subjective chest pain, dyspnea. However, this symptomatology is not always present in a clozapine-related pericarditis. Some authors suggest measuring BNP levels to detect early and asymptomatic cardiac dysfunction. We here report the clinical cases of two women, respectively 22 and 28 years old. They both suffered from an early onset resistant schizophrenia. Clozapine was gradually introduced, at a dose of 200 mg/day, in both patients. After about one month in both cases, while the first patient was nearly asymptomatic, apart from the intermittent fever (only PCR and pro-BNP values were elevated, 16.88 mg/dL and 1004 pg/mL, respectively), the second one showed a classic symptomatology suggestive of pericarditis. Clozapine was discontinued in both patients, resulting in progressive resolution of pericarditis. Interestingly, in the patient in which pro-BNP was elevated, after clozapine cessation, the pro-BNP fell down dramatically. Pro-BNP plasma levels appears to be an interesting test in identifying subjects with asymptomatic cardiac impairment. It would be useful to evaluate if early treatment with beta-blockers and ACE-inhibitors may allow the prosecution of clozapine treatment after developing of mild signs of cardiac toxicity in drug resistant schizophrenic patients responsive to clozapine.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Chest conduction properties and ECG equalization

In common practice of detecting and recording biomedical signals, it is often implicitly assumed that the propagation, through the whole circuit human body-electrodes recording devices, is frequency and voltage independent. As a consequence, clinicians are not aware that recorded signals do not correspond faithfully to the original electrical activity of organs under investigation. We have studied the transmission of electrical signals in human body at various voltages and frequencies to understand if and to which extent the most diffused stimulating and recording techniques used in medicine are affected by global body conduction properties. Our results show that, in order to obtain a more faithful detection of electrical activity produced or evoked by human organs (e.g. EGG, electromyography, etc.), it is convenient to 'equalize'' recorded signals. To this purpose, two equalization techniques are proposed, based, respectively, on a simple hardware filtering during acquisition, or FFT post-processing of the acquired signals. As an application, we have studied the transmission of electrical signal in human chest and have compared equalized high frequency ECG signals with raw (original) recordings.

Hippocampal synaptic plasticity: effects of neonatal stress in freely moving adult male rats

The present study examines the effects of neonatal isolation on hippocampal LTP in adult male rats. Changes in dentate granule cell population measures, i.e., EPSP slope and population spike amplitude (PSA), evoked by tetanization of the medial perforant pathway were used to assess the effects of neonatal isolation on LTP over a period of 96 h. Following tetanization significant group differences were obtained for input/output (I/O) response measures of EPSP slope and PSA, with isolated males showing consistently higher values than in the other two groups. Comparisons made at 1 h post-tetanization (establishment of LTP) indicated that isolated males showed significantly greater enhancement than any other group. At 96 h (maintenance of LTP), however, neonatally isolated males showed significantly greater enhancement than either non-isolated siblings or unhandled controls. Additionally, isolation resulted in prolonging the duration of enhancement obtained from males. Thus, males show different enhancement profiles with respect to both the magnitude and duration of LTP and neonatal isolation alters these profiles in profound manner.