Evidence for a peptidic factor in spermatozoa inhibiting the ovarian maturation

The presence in bull spermatozoa of a specific, non-steroidal-inhibiting factor of ovarian muturation is shown. Its extraction and partial purification are reported.The inhibitor is active at the 1 μg level. No linear dose-response correlation was observed.The peptidic nature of the inhibitor is proved by experiments carried out using proteolytic enzymes.     

Causes of Death in a Contemporary Cohort of Patients with Invasive Aspergillosis

Information regarding the processes leading to death in patients with invasive aspergillosis (IA) is lacking. We sought to determine the causes of death in these patients, the role that IA played in the cause, and the timing of death. The factors associated with IA-related mortality are also analyzed. We conducted a multicenter study (2008-2011) of cases of proven and probable IA. The causes of death and whether mortality was judged to be IA-related or IA-unrelated were determined by consensus using a six-member review panel. A multivariate analysis was performed to determine risk factors for IA-related death. Of 152 patients with IA, 92 (60.5%) died. Mortality was judged to be IA-related in 62 cases and IA-unrelated in 30. The most common cause of IA-related death was respiratory failure (50/62 patients), caused primarily by Aspergillus infection, although also by concomitant infections or severe comorbidities. Progression of underlying disease and bacteremic shock were the most frequent causes of IA-unrelated death. IA-related mortality accounted for 98% and 87% of deaths within the first 14 and 21 days, respectively. Liver disease (HR 4.54; 95% CI, 1.69-12.23) was independently associated with IA-related mortality, whereas voriconazole treatment was associated with reduced risk of death (HR 0.43; 95% CI, 0.20-0.93). In conclusion, better management of lung injury after IA diagnosis is the main challenge for physicians to improve IA outcomes. There are significant differences in causes and timing between IA-related and IA–unrelated mortality and these should be considered in future research to assess the quality of IA care.     

Prenatal Treatment Prevents Learning Deficit in Down Syndrome Model

Down syndrome is the most common genetic cause of mental retardation. Active fragments of neurotrophic factors release by astrocyte under the stimulation of vasoactive intestinal peptide, NAPVSIPQ (NAP) and SALLRSIPA (SAL) respectively, have shown therapeutic potential for developmental delay and learning deficits. Previous work demonstrated that NAP+SAL prevent developmental delay and glial deficit in Ts65Dn that is a well-characterized mouse model for Down syndrome. The objective of this study is to evaluate if prenatal treatment with these peptides prevents the learning deficit in the Ts65Dn mice. Pregnant Ts65Dn female and control pregnant females were randomly treated (intraperitoneal injection) on pregnancy days 8 through 12 with saline (placebo) or peptides (NAP 20 µg +SAL 20 µg) daily. Learning was assessed in the offspring (8–10 months) using the Morris Watermaze, which measures the latency to find the hidden platform (decrease in latency denotes learning). The investigators were blinded to the prenatal treatment and genotype. Pups were genotyped as trisomic (Down syndrome) or euploid (control) after completion of all tests. Statistical analysis: two-way ANOVA followed by Neuman-Keuls test for multiple comparisons, P<0.05 was used to denote statistical significance. Trisomic mice who prenatally received placebo (Down syndrome -placebo; n = 11) did not demonstrate learning over the five day period. DS mice that were prenatally exposed to peptides (Down syndrome-peptides; n = 10) learned significantly better than Down syndrome -placebo (p<0.01), and similar to control-placebo (n = 33) and control-peptide (n = 30). In conclusion prenatal treatment with the neuroprotective peptides (NAP+SAL) prevented learning deficits in a Down syndrome model. These findings highlight a possibility for the prevention of sequelae in Down syndrome and suggest a potential pregnancy intervention that may improve outcome.     

Biomonitoring with Honeybees of Heavy Metals and Pesticides in Nature Reserves of the Marche Region (Italy)

The aim of this study was to carry out biomonitoring with honeybees (Apis mellifera L.) to assess the presence of pesticides and heavy metals (cadmium, chromium, nickel, lead) in all of the ten nature reserves of the Marche Region (central–eastern Italy). The study was carried out during the spring and summer seasons when the honeybees were active, over 3 years (2008–2010). Twenty-two colonies of honeybees bred in hives were used. Samples of live and dead honeybees and of honey were collected from 11 sampling stations from May to October in each year. No pesticide pollution was found. Significant differences in heavy metal concentrations were found among years, months and sites, and in particular situations. The analysis reveals that high heavy-metal concentrations occurred exclusively in live honeybees. For the seasonal averages, the most detected heavy metal was chromium, which exceeded the threshold more often than for the other elements, followed by cadmium and lead; nickel never exceeded the threshold. The data are discussed with an evaluation of the natural and anthropic sources taken from the literature and from local situations that were likely to involve heavy metal pollution.     

Development-related changes of protein ubiquitination in pollen from male and female kiwifruit (Actinidia deliciosa)

Kiwifruit (Actinidia deliciosa) is a dioecious vine whose staminate and pistillate flowers nonetheless develop non-functional reproductive structures of the ompposite sex. Ubiquitin is a small, highly conserved protein found in all eucaryotes: a covalent ATP-dependent attachment of ubiquitin marks proteins for degradation. In the present paper, we used immunoblotting to investigate the presence of free ubiquitin and ubiquitin conjugates during pollen development in male (androfertile) and in female (androsterile) genotypes of kiwifruit. In the male, several high molecular mass protein conjugates were present throughout development. On the contrary, such a pattern characterized only early stages of pollen from the female genotype, where conjugates progressively disamppeared, until they were detectable only in trace amounts at anthesis. The highest content of conjugates in the male genotype was observed when microspores were ampproaching the first mitosis. Free ubiquitin increased continuously during development of the male microgametophyte so that mature pollen contained considerable amounts of the ubiquitin monomer at the time of its release from the anther. By contrast, only low levels were detectable in the degenerating microspores in the pistillate flowers. In vitro experiments using labeled ubiquitin indicated that early-uninucleate microspores of the female genotype had a much higher conjugation rate than those of the male genotype at the same stage. However, after feeding α-lactalbumin as exogenous substrate, the rate of ubiquitin conjugation strongly increased and was quite similar in both sexes. Nuclear features of pollen development in both genotypes are also described. The nucleus progressively degenerated in the microspores of the pistillate flowers starting from the early-uninucleate stage, in parallel with the progressive decrease in ubiquitin content and activity. At anthesis, the microspores in the pistillate flowers either had no nucleus or showed only traces of chromatin. Thus, the ubiquitin system seems to play an important role in protein turnover occurring during the normal developmental pathway of the kiwifruit microgametophyte, while it was mainly involved in regressive events related to microspore degeneration in the female genotype.     

Massive iron accumulation in PKAN-derived neurons and astrocytes: light on the human pathological phenotype

Neurodegeneration associated with defective pantothenate kinase-2 (PKAN) is an early-onset monogenic autosomal-recessive disorder. The hallmark of the disease is the massive accumulation of iron in the globus pallidus brain region of patients. PKAN is caused by mutations in the PANK2 gene encoding the mitochondrial enzyme pantothenate kinase-2, whose function is to catalyze the first reaction of the CoA biosynthetic pathway. To date, the way in which this alteration leads to brain iron accumulation has not been elucidated. Starting from previously obtained hiPS clones, we set up a differentiation protocol able to generate inhibitory neurons. We obtained striatal-like medium spiny neurons composed of approximately 70–80% GABAergic neurons and 10–20% glial cells. Within this mixed population, we detected iron deposition in both PKAN cell types, however, the viability of PKAN GABAergic neurons was strongly affected. CoA treatment was able to reduce cell death and, notably, iron overload. Further differentiation of hiPS clones in a pure population of astrocytes showed particularly evident iron accumulation, with approximately 50% of cells positive for Perls staining. The analysis of these PKAN astrocytes indicated alterations in iron metabolism, mitochondrial morphology, respiratory activity, and oxidative status. Moreover, PKAN astrocytes showed signs of ferroptosis and were prone to developing a stellate phenotype, thus gaining neurotoxic features. This characteristic was confirmed in iPS-derived astrocyte and glutamatergic neuron cocultures, in which PKAN glutamatergic neurons were less viable in the presence of PKAN astrocytes. This newly generated astrocyte model is the first in vitro disease model recapitulating the human phenotype and can be exploited to deeply clarify the pathogenetic mechanisms underlying the disease.Subject terms: Neurodegeneration, Neurodegeneration     

Identification of Conserved Epitopes in SARS-CoV-2 Spike and Nucleocapsid Protein

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel virus that first occurred in Wuhan in December 2019. The spike glycoproteins and nucleocapsid proteins are the most common targets for the development of vaccines and antiviral drugs.ObjectiveWe herein analyze the rate of evolution along with the sequences of spike and nucleocapsid proteins in relation to the spatial locations of their epitopes, previously suggested to contribute to the immune response caused by SARS-CoV-2 infections.MethodsWe compare homologous proteins of seven human coronaviruses: HCoV-229E, HCoV-OC43, SARS-CoV, HCoV-NL63, HCoV-HKU1, MERS-CoV, and SARS-CoV-2. We then focus on the local, structural order-disorder propensity of the protein regions where the SARS-CoV-2 epitopes are located. ResultsWe show that most of nucleocapsid protein epitopes overlap the RNA-binding and dimerization domains, and some of them are characterized by a low rate of evolutions. Similarly, spike protein epitopes are preferentially located in regions that are predicted to be ordered and well- conserved, in correspondence of the heptad repeats 1 and 2. Interestingly, both the receptor-binding motif to ACE2 and the fusion peptide of spike protein are characterized by a high rate of evolution.ConclusionOur results provide evidence for conserved epitopes that might help develop broad-spectrum SARS-CoV-2 vaccines.     

Individualizing Risk of Multidrug-Resistant Pathogens in Community-Onset Pneumonia

Introduction

The diffusion of multidrug-resistant (MDR) bacteria has created the need to identify risk factors for acquiring resistant pathogens in patients living in the community.

Objective

To analyze clinical features of patients with community-onset pneumonia due to MDR pathogens, to evaluate performance of existing scoring tools and to develop a bedside risk score for an early identification of these patients in the Emergency Department.

Patients and Methods

This was an open, observational, prospective study of consecutive patients with pneumonia, coming from the community, from January 2011 to January 2013. The new score was validated on an external cohort of 929 patients with pneumonia admitted in internal medicine departments participating at a multicenter prospective study in Spain.

Results

A total of 900 patients were included in the study. The final logistic regression model consisted of four variables: 1) one risk factor for HCAP, 2) bilateral pulmonary infiltration, 3) the presence of pleural effusion, and 4) the severity of respiratory impairment calculated by use of PaO2/FiO2 ratio. A new risk score, the ARUC score, was developed; compared to Aliberti, Shorr, and Shindo scores, this point score system has a good discrimination performance (AUC 0.76, 95% CI 0.71-0.82) and calibration (Hosmer-Lemeshow, χ2 = 7.64; p = 0.469). The new score outperformed HCAP definition in predicting etiology due to MDR organism. The performance of this bedside score was confirmed in the validation cohort (AUC 0.68, 95% CI 0.60-0.77).

Conclusion

Physicians working in ED should adopt simple risk scores, like ARUC score, to select the most appropriate antibiotic regimens. This individualized approach may help clinicians to identify those patients who need an empirical broad-spectrum antibiotic therapy.