Influenza and Covid-19 Vaccination in 2023: a descriptive analysis in two Italian Research and Teaching Hospitals. Is the On-Site strategy effective?

Introduction: Vaccinations represent an extremely effective tool for the prevention of certain infectious diseases - such as influenza and COVID-19 -, particularly for those categories at risk due to both their frail condition or professional exposure, such as healthcare workers. The aim of this study is to describe the course of the anti-influenza and anti-COVID-19 vaccination campaign at two Research Hospitals in Milan, Italy. Study design: Multicentre, cross-sectional study. Methods: For the 2023-24 vaccination campaign, the two facilities opted for two different approaches. At the Hospital A, two dif-ferent strategies for vaccinating healthcare workers were implemented: a fixed-site vaccination clinic and two mobile vaccination groups run by Public Health residents of the University of Milan. At the Hospital B, on the other hand, a single fixed-site outpatient clinic run by Public Health residents of the University of Milan was used. On the occasion of the campaign, a survey was also carried out using anonymous online questionnaires to investigate healthcare workers attitudes towards vaccination. Results: A total of 1,937 healthcare workers were vaccinated: 756 were immunized against influenza only, 99 against COVID-19 only, and 1,082 against both. The results show a substantial difference in vaccination adherence among medical and nursing staff compared to other professional categories. In particular, the category with the highest vaccination adhesion turned out to be that of medical doctors with 55.7% adhesion while, on the contrary, the category with the lowest adhesion turned out to be that of auxiliary personnel characterized by 7.4% adhesion. At the same time, the comparison between the two hospital facilities showed a double adherence rate by the staff of Hospital A as regards both the flu vaccine (40.6% and 20.1%) and the anti-COVID-19 vaccine (26.4% and 12.3%). Finally, the survey showed that the attitude towards influenza vaccination is lower among auxiliary staff in terms of both knowledge and vaccination attitude. Conclusions: The results of the study show a vaccination adherence in line with that of previous years, although lower than the values recommended by the principal national and international Organizations. The analysis of the differences between the two facilities and the surveys carried out will allow for the implementation of targeted interventions to increase adherence in future campaigns.

Burden of caregiving for cardiovascular dysautonomia in Parkinson's disease.

PURPOSE: We sought to estimate the impact of cardiovascular autonomic neuropathy (cAN) on informal caregivers of patients with Parkinson's disease (PD), defined as individuals providing regular care to a friend, partner, or family member with PD, and to evaluate the mutual relationship between caregiver burden and patient health-related quality of life (HRQoL). METHODS: We enrolled 36 consecutive patients with PD and their informal caregivers. Patients underwent a detailed motor, autonomic, cognitive, and functional assessment. Caregivers were assessed using the Zarit Burden Interview (ZBI). Differences in caregiver burden, expressed by the ZBI score, and strength of association between caregiver burden, cAN, and HRQoL were assessed using analysis of covariance (ANCOVA), logistic regression, and linear regression analyses. Analyses were adjusted for patients' age, PD duration, and motor and cognitive disability, as well as caregivers' age. RESULTS: Moderate-severe caregiver burden was reported in 41.7% of PDcAN+ versus 8.7% of PDcAN- (p < 0.001). The ZBI score was increased in PDcAN+ versus PDcAN- (31.5 ± 3.4 versus 15.2 ± 2.3; p < 0.001), with tenfold higher odds (p = 0.012) of moderate-severe caregiver burden in PDcAN+, even after adjusting for potential confounders. The ZBI score correlated with cAN severity (p = 0.005), global autonomic impairment (p = 0.012), and HRQoL impairment (p < 0.001). CONCLUSION: These results highlight the significant impact of cAN on PD caregivers and the need for targeted interventions addressing this frequently overlooked and insufficiently treated source of nonmotor disability in PD.

Structure and mechanism of the 6-oxopurine nucleosidase from Trypanosoma brucei brucei.

Trypanosomes are purine-auxotrophic parasites that depend upon nucleoside hydrolase (NH) activity to salvage nitrogenous bases necessary for nucleic acid and cofactor synthesis. Nonspecific and purine-specific NHs have been widely studied, yet little is known about the 6-oxopurine-specific isozymes, although they are thought to play a primary role in the catabolism of exogenously derived nucleosides. Here, we report the first functional and structural characterization of the inosine-guanosine-specific NH from Trypanosoma brucei brucei. The enzyme shows near diffusion-limited efficiency coupled with a clear specificity for 6-oxopurine nucleosides achieved through a catalytic selection of these substrates. Pre-steady-state kinetic analysis reveals ordered product release, and a rate-limiting structural rearrangement that is associated with the release of the product, ribose. The crystal structure of this trypanosomal NH determined to 2.5 Å resolution reveals distinctive features compared to those of both purine- and pyrimidine-specific isozymes in the framework of the conserved and versatile NH fold. Nanomolar iminoribitol-based inhibitors identified in this study represent important lead compounds for the development of novel therapeutic strategies against trypanosomal diseases.

Crystal structure of a ternary complex of the alcohol dehydrogenase from Sulfolobus solfataricus.

The crystal structure of a ternary complex of the alcohol dehydrogenase from the archaeon Sulfolobus solfataricus (SsADH) has been determined at 2.3 A. The asymmetric unit contains a dimer with a NADH and a 2-ethoxyethanol molecule bound to each subunit. The comparison with the apo structure of the enzyme reveals that this medium chain ADH undergoes a substantial conformational change in the apo-holo transition, accompanied by loop movements at the domain interface. The extent of domain closure is similar to that observed for the classical horse liver ADH, although some differences are found which can be related to the different oligomeric states of the enzymes. Compared to its apo form, the SsADH ternary complex shows a change in the ligation state of the active site zinc ion which is no longer bound to Glu69, providing additional evidence of the dynamic role played by the conserved glutamate residue in ADHs. In addition, the structure presented here allows the identification of the substrate site and hence of the residues that are important in the binding of both the substrate and the coenzyme.

Structural study of a single-point mutant of Sulfolobus solfataricus alcohol dehydrogenase with enhanced activity.

Alcohol dehydrogenase from Sulfolobus solfataricus (SsADH) is the only enzyme from Archaea among the structurally studied members of the medium-chain ADH family described so far. Here, we present the three-dimensional structure of the apo form of the mutant N249Y which exhibits increased catalytic activity when compared to the wild-type enzyme. The substitution, located in the coenzyme binding domain, decreases the affinity for NAD(H) cofactor. The rearrangement of segments 248-250 and 270-275, induced by the mutation, suggests an explanation for the lower coenzyme affinity. This study also highlights the role in SsADH catalysis of the flexible loops located at the interface between the catalytic and the coenzyme domains.