CoCas9 is a compact nuclease from the human microbiome for efficient and precise genome editing

The expansion of the CRISPR-Cas toolbox is highly needed to accelerate the development of therapies for genetic diseases. Here, through the interrogation of a massively expanded repository of metagenome-assembled genomes, mostly from human microbiomes, we uncover a large variety (n = 17,173) of type II CRISPR-Cas loci. Among these we identify CoCas9, a strongly active and high-fidelity nuclease with reduced molecular size (1004 amino acids) isolated from an uncultivated Collinsella species. CoCas9 is efficiently co-delivered with its sgRNA through adeno associated viral (AAV) vectors, obtaining efficient in vivo editing in the mouse retina. With this study we uncover a collection of previously uncharacterized Cas9 nucleases, including CoCas9, which enriches the genome editing toolbox.

Characterization of microplastics in skim-milk powders

The diffusion of microplastics in the food supply chain is prompting public concern as their impact on human health is still largely unknown. The aim of this study was to qualitatively and quantitatively characterize microplastics in skim-milk powder samples (n = 16) from different European countries (n = 8) through Fourier-transform infrared micro-spectroscopy in attenuated total reflectance mode analysis. The present study highlights that the use of hot alkaline digestion has enabled the efficacious identification of microplastics in skim-milk powders used for cheese-making across European countries. The adopted protocol allowed detection of 29 different types of polymeric matrices for a total of 536 plastic particles. The most abundant microplastics were polypropylene, polyethylene, polystyrene, and polyethylene terephthalate. Microplastics were found in skim-milk powders in 3 different shapes (fiber, sphere, and irregular fragments) and 6 different colors (black, blue, brown, fuchsia, green, and gray). Results demonstrate the presence of microplastics in all skim-milk powder samples, suggesting a general contamination. Results of the present study will help to evaluate the impact of microplastics intake on human health.

Assessment of energy dispersive X-ray fluorescence (ED-XRF) for quantification of iodine in non-lyophilized milk

Iodine represents a fundamental element for human health, with particular regard to thyroid function. Dietary intake of milk naturally rich in iodine becomes of primary importance in the prevention of syndromes related to iodine deficiency. The concentration of iodine in milk is characterized by wide variability, mainly related to animal feed and level of mineral supplementation. Therefore, there is interest in the development of fast analytical techniques which are able to predict milk iodine concentration. The aim of the present study was to investigate the effectiveness of energy-dispersive X-ray fluorescence (ED-XRF) for the prediction of iodine in cow milk. Results showed moderate accuracy of the ED-XRF technique, with a coefficient of determination in cross validation of 0.60. This study represents a first contribution towards the possibility to discriminate milk with high or low iodine concentration, as an essential preliminary step for the introduction into the market of naturally fortified milk.

Automated identification of sequence-tailored Cas9 proteins using massive metagenomic data

The identification of the protospacer adjacent motif (PAM) sequences of Cas9 nucleases is crucial for their exploitation in genome editing. Here we develop a computational pipeline that was used to interrogate a massively expanded dataset of metagenome and virome assemblies for accurate and comprehensive PAM predictions. This procedure allows the identification and isolation of sequence-tailored Cas9 nucleases by using the target sequence as bait. As proof of concept, starting from the disease-causing mutation P23H in the RHO gene, we find, isolate and experimentally validate a Cas9 which uses the mutated sequence as PAM. Our PAM prediction pipeline will be instrumental to generate a Cas9 nuclease repertoire responding to any PAM requirement.

MRI and visual-evoked potentials in partners of multiple sclerosis patients

OBJECTIVE

Some epidemiological evidence, particularly concerning the role of Epstein Barr Virus implies that multiple sclerosis (MS) may be transmissible and if correct, this might be revealed by increased prevalence of MS in cohabiting partners.

METHODS

We addressed this problem by neurological assessment, visual-evoked potentials (VEP) and magnetic resonance imaging (MRI) in 112 partners of patients with MS in comparison to a control group of 93 individuals with clinically non-significant head or neck pain and in comparison to UK prevalence.

RESULTS

We found one instance of conjugal definite MS. Including this case, VEP were abnormal in five instances with either significant delay (n = 3) or increased interocular latency difference (IOLD) (n = 2) in partners of MS patients thus raising the possibility of subclinical optic nerve demyelination. The mean absolute value of IOLD in partners was greater than the value in controls (P = 0.033). There were no significant differences in MRI findings between the two groups.

CONCLUSION

The finding of one conjugal pair and abnormal VEP in a further four MS partners could have several explanations. It is compatible with the concept of a transmissible agent, although our observations could be due to several biases as well as the play of chance alone.

[Development of a new strategy for minimal residual disease monitoring in children with B-precursor acute lymphoblastic leukemia]

Despite modern regimen of chemotherapy, one-third of children with acute lymphoblastic leukaemia relapse. Recent studies have shown that a high level of minimal residual disease (MRD) at the end of induction is associated with an increased risk of relapse. We have developed and validated a real-time PCR method (RQ-PCR) to quantify MRD. We monitored 57 patients using IgH and TCR (Vdelta2Ddelta3) genes rearrangements as PCR targets. RQ-PCR was performed with a primer and a TaqMan probe designed to consensus sequences in VH segments in combination with one allele specific oligonucleotide primer complementary to the junctionnal region. A sensitivity of 10(-4) was reached for 72% of the IgH alleles (n = 50) and for 54,5% of the Vdelta2Ddelta3 alleles (n = 22). We compared the results with those obtained by competitive PCR in 53 patients: no discordance between the two methods was observed. Seventeen patients were found positive (32%) and 27 negative (51%) with both techniques and 9 children (17%) were positive only with TaqMan technology. RQ-PCR is more sensitive and more specific than competitive PCR. We thus propose that RQ-PCR might be used in first intention for MRD analysis.

[Extensive cardiac angiosarcoma in the course of immunosuppressive therapy after kidney transplant]

We present a case of a 49-year-old man who underwent a kidney transplant. Treatment with azathioprine and steroid was increased due to an initial rejection of the allograft. Six months later, the patient experienced palpitations and precordial pain: the electrocardiogram recorded atrial fibrillation and the echocardiogram showed moderate pericardial effusion and the presence of a right atrial mass with infiltration into the interatrial septum and right ventricle. Computed tomography imaging confirmed the tumoral mass and magnetic resonance imaging revealed the extensive involvement of the right atrium, right ventricle and superior vena cava, suggesting the presence of an angiosarcoma of the heart. Despite chemotherapy the patient died within 1 month. The diagnosis was confirmed by autopsy, histological section, and electron microscopy examination.

[Coding and identification of heart failure]

The prevalence of the diagnosis of heart failure (HF) presents large differences, comparing the data of hospital discharge obtained from USA and Italy through te code 428 of ninth revision of International Classification of Diseases (ICD-9). As possibly the difference is related to classification, we reviewed homogeneous diagnosis in Padua General Hospital as a whole and the diagnosis at discharge in the department of Cardiology of the same hospital. Hospital HF discharge rate is on average 0.43% (0.37-0.51); while from department of Cardiology is on average 0.7% (0.15-0.85). Medical records of a group of patients (the first hundred of 1992) are analysed and recorded using the Boston criteria for scoring the certainty of HF diagnosis. The group with unlikely HF (68%) does'nt codes 428; there is 2 code 428 in group with possible (16%) and 2 in group with definite (16%) diagnosis of HF. The physician probably prefers sometimes an anatomical rather than a functional classification and therefore he underscores the impairment of left ventricular systolic function. A better code-use is needed before comparing prevalence rate from different centres.

Ultrasonography in the evaluation of osteogenesis in fractures treated with Hoffmann external fixation

The possibilities of ultrasonography demonstrating periosteal callus and osteogenesis at the fracture focus are described. Illustrative cases are presented and the advantages of this technique are discussed. It is emphasized that ultrasonography is a noninvasive technique that may be repeated as often as is necessary. It provides images of appositional periosteal callus much earlier than radiography, thus facilitating early evaluation of the treatment employed.

Water-path echotomography in differential diagnosis of scrotal masses

Experience with Octoson water-path echotomography in examining 21 testicular masses is reported. Sonographic results were confirmed by surgical and pathologic findings in all cases. We believe this procedure to be of value in differential diagnosis of intrascrotal swellings.