298 research outputs found

    Assembly of the Inner Perivitelline Layer, a Homo log of the Mammalian Zona Pellucida: An Immunohistochemical and Ultrastructural Study

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    The avian inner perivitelline layer (IPVL), a homologous structure to the mammalian zona pellucida, is deposited between the granulosa cells and the oocyte cell membrane during folliculogenesis. The glycoprotein meshwork of the IPVL forms a 3-dimensional matrix and possesses important functions in the fertilization process: it contributes to the binding of avian spermatozoa to the oocyte and induces acrosomal exocytosis. In contrast to the zona pellucida of mammals, the IPVL does not prevent the physiological polyspermy found in birds. Previous studies have shown that in the Japanese quail (Cotumix japonica) at least 5 glycoproteins are constituents of the IPVL (ZP1, ZP2, ZP3, ZP4, and ZPD). In this study, we investigated the spatiotennporal assembly pattern of the IPVL during folliculogenesis using immunohistochemical and ultrastructural methods. The obtained results clearly show that these glycoproteins are incorporated into the IPVL at distinct points during follicular development, supporting the hypothesis that ZP2 and ZP4 form a type of prematrix into which ZP1, ZP3, and ZPD are integrated at a later stage of development. Copyright (C) 2011 S. Karger AG, Base

    The serine protease hepsin mediates urinary secretion and polymerisation of Zona Pellucida domain protein uromodulin.

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    Uromodulin is the most abundant protein in the urine. It is exclusively produced by renal epithelial cells and it plays key roles in kidney function and disease. Uromodulin mainly exerts its function as an extracellular matrix whose assembly depends on a conserved, specific proteolytic cleavage leading to conformational activation of a Zona Pellucida (ZP) polymerisation domain. Through a comprehensive approach, including extensive characterisation of uromodulin processing in cellular models and in specific knock-out mice, we demonstrate that the membrane-bound serine protease hepsin is the enzyme responsible for the physiological cleavage of uromodulin. Our findings define a key aspect of uromodulin biology and identify the first in vivo substrate of hepsin. The identification of hepsin as the first protease involved in the release of a ZP domain protein is likely relevant for other members of this protein family, including several extracellular proteins, as egg coat proteins and inner ear tectorins

    Porto-systemic shunt using adrenal vein as a conduit; an alternative procedure for spleno – renal shunt

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    PubMed ID: 17555599Background. Currently, portal hypertension is still big problem for the patients with serious liver diseases. Variceal bleeding is one of the most important complications of portal hypertension. In case of failure of endoscopic and combined medical treatments, surgical decompressive shunts are required. We emphasized an alternative splenorenal shunt procedure using adrenal vein as a conduit. Case presentation. A 26-year-old male suffered from recurrent variceal bleeding was considered for surgical therapy. Although we planned to perform a distal splenorenal shunt procedure, it was observed to be difficult. Therefore left adrenal vein was used as a conduit between left renal vein and splenic vein after splenic artery was ligated. He did well and was discharged from the hospital on the postoperative day 6. In the follow up period for nine months, endoscopic and ultrasonographic examinations were normal. Conclusion. We concluded that, in case of failure to perform distal splenorenal shunt due to technical problems, alternative porto-systemic shunt procedure using the adrenal vein as a vascular conduit can be safely employed. © 2007 Aydin et al; licensee BioMed Central Ltd

    Impact of COVID-19 on the oncological outcomes of colorectal cancer surgery in northern Italy in 2019 and 2020: multicentre comparative cohort study

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    BACKGROUND: This study compared patients undergoing colorectal cancer surgery in 20 hospitals of northern Italy in 2019 versus 2020, in order to evaluate whether COVID-19-related delays of colorectal cancer screening resulted in more advanced cancers at diagnosis and worse clinical outcomes. METHOD: This was a retrospective multicentre cohort analysis of patients undergoing colorectal cancer surgery in March to December 2019 versus March to December 2020. Independent predictors of disease stage (oncological stage, associated symptoms, clinical T4 stage, metastasis) and outcome (surgical complications, palliative surgery, 30-day death) were evaluated using logistic regression. RESULTS: The sample consisted of 1755 patients operated in 2019, and 1481 in 2020 (both mean age 69.6 years). The proportion of cancers with symptoms, clinical T4 stage, liver and lung metastases in 2019 and 2020 were respectively: 80.8 versus 84.5 per cent; 6.2 versus 8.7 per cent; 10.2 versus 10.3 per cent; and 3.0 versus 4.4 per cent. The proportions of surgical complications, palliative surgery and death in 2019 and 2020 were, respectively: 34.4 versus 31.9 per cent; 5.0 versus 7.5 per cent; and 1.7 versus 2.4 per cent. Cancers in 2020 (versus 2019) were more likely to be symptomatic (odds ratio 1.36 (95 per cent c.i. 1.09 to 1.69)), clinical T4 stage (odds ratio 1.38 (95 per cent c.i. 1.03 to 1.85)) and have multiple liver metastases (odds ratio 2.21 (95 per cent c.i. 1.24 to 3.94)), but were not more likely to be associated with surgical complications (odds ratio 0.79 (95 per cent c.i. 0.68 to 0.93)). CONCLUSION: Colorectal cancer patients who had surgery between March and December 2020 had an increased risk of advanced disease in terms of associated symptoms, cancer location, clinical T4 stage and number of liver metastases

    Mutational and phenotypic characterisation of hereditary hemorrhagic telangiectasia

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    Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular dysplasia. Care delivery for HHT patients is impeded by the need for laborious, repeated phenotyping and gaps in knowledge regarding the relationships between causal DNA variants in ENG, ACVRL1, SMAD4 and GDF2, and clinical manifestations. To address this, we analyzed DNA samples from 183 previously uncharacterized, unrelated HHT and suspected HHT cases using the ThromboGenomics high-throughput sequencing platform. We identified 127 rare variants across 168 heterozygous genotypes. Applying modified American College of Medical Genetics and Genomics Guidelines, 106 variants were classified as pathogenic/likely pathogenic and 21 as nonpathogenic (variant of uncertain significance/benign). Unlike the protein products of ACVRL1 and SMAD4, the extracellular ENG amino acids are not strongly conserved. Our inferences of the functional consequences of causal variants in ENG were therefore informed by the crystal structure of endoglin. We then compared the accuracy of predictions of the causal gene blinded to the genetic data using 2 approaches: subjective clinical predictions and statistical predictions based on 8 Human Phenotype Ontology terms. Both approaches had some predictive power, but they were insufficiently accurate to be used clinically, without genetic testing. The distributions of red cell indices differed by causal gene but not sufficiently for clinical use in isolation from genetic data. We conclude that parallel sequencing of the 4 known HHT genes, multidisciplinary team review of variant calls in the context of detailed clinical information, and statistical and structural modeling improve the prognostication and treatment of HHT

    Evolution of minimally invasive techniques and surgical outcomes of ALPPS in Italy: a comprehensive trend analysis over 10 years from a national prospective registry

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    BackgroundSince 2012, Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) has encountered several modifications of its original technique. The primary endpoint of this study was to analyze the trend of ALPPS in Italy over a 10-year period. The secondary endpoint was to evaluate factors affecting the risk of morbidity/mortality/post-hepatectomy liver failure (PHLF).MethodsData of patients submitted to ALPPS between 2012 and 2021 were identified from the ALPPS Italian Registry and evaluation of time trends was performed.ResultsFrom 2012 to 2021, a total of 268 ALPPS were performed within 17 centers. The number of ALPPS divided by the total number of liver resections performed by each center slightly declined (APC = - 2.0%, p = 0.111). Minimally invasive (MI) approach significantly increased over the years (APC = + 49.5%, p = 0.002). According to multivariable analysis, MI completion of stage 1 was protective against 90-day mortality (OR = 0.05, p = 0.040) as well as enrollment within high-volume centers for liver surgery (OR = 0.32, p = 0.009). Use of interstage hepatobiliary scintigraphy (HBS) and biliary tumors were independent predictors of PHLF.ConclusionsThis national study showed that use of ALPPS only slightly declined over the years with an increased use of MI techniques, leading to lower 90-day mortality. PHLF still remains an open issue

    Zona Pellucida Domain-Containing Protein β-Tectorin is Crucial for Zebrafish Proper Inner Ear Development

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    BACKGROUND: The zona pellucida (ZP) domain is part of many extracellular proteins with diverse functions from structural components to receptors. The mammalian β-tectorin is a protein of 336 amino acid residues containing a single ZP domain and a putative signal peptide at the N-terminus of the protein. It is 1 component of a gel-like structure called the tectorial membrane which is involved in transforming sound waves into neuronal signals and is important for normal auditory function. β-Tectorin is specifically expressed in the mammalian and avian inner ear. METHODOLOGY/PRINCIPAL FINDINGS: We identified and cloned the gene encoding zebrafish β-tectorin. Through whole-mount in situ hybridization, we demonstrated that β-tectorin messenger RNA was expressed in the otic placode and specialized sensory patch of the inner ear during zebrafish embryonic stages. Morpholino knockdown of zebrafish β-tectorin affected the position and number of otoliths in the ears of morphants. Finally, swimming behaviors of β-tectorin morphants were abnormal since the development of the inner ear was compromised. CONCLUSIONS/SIGNIFICANCE: Our results reveal that zebrafish β-tectorin is specifically expressed in the zebrafish inner ear, and is important for regulating the development of the zebrafish inner ear. Lack of zebrafish β-tectorin caused severe defects in inner ear formation of otoliths and function

    A Non-synonymous point mutation in a WD-40 domain repeat of EML5 leads to decreased bovine sperm quality and fertility.

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    This study is part of a concerted effort to identify and phenotype rare, deleterious mutations that adversely affect sperm quality, or convey high developmental and fertility potential to embryos and ensuing progeny. A rare, homozygous mutation in EML5 (EML5R1654W), which encodes a microtubule-associated protein with high expression in testis and brain was identified in an Angus bull used extensively in artificial insemination (AI) for its outstanding progeny production traits. The bull?s fertility was low in cross-breeding timed AI (TAI) (Pregnancy/TAI = 25.2%; n = 222) and, in general, AI breeding to Nellore cows (41%; n = 822). A search of the 1,000 Bull Genomes Run9 database revealed an additional 74 heterozygous animals and 8 homozygous animals harboring this exact mutation across several different breeds (0.7% frequency within the 6,191 sequenced animals). Phenotypically, spermatozoa from the homozygous Angus bull displayed prominent piriform and tapered heads, and outwardly protruding knobbed acrosomes. Additionally, an increased retention of EML5 was also observed in the sperm head of both homozygous and heterozygous Angus bulls compared to wild-type animals. This non-synonymous point mutation is located within a WD40 signaling domain repeat of EML5 and is predicted to be detrimental to overall protein function by genomic single nucleotide polymorphism (SNP) analysis and protein modeling. Future work will examine how this rare mutation affects field AI fertility and will characterize the role of EML5 in spermatogenesis

    Simultaneous resection of colorectal cancer and synchronous liver metastases: what determines the risk of unfavorable outcomes? An international multicenter retrospective cohort study

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    BACKGROUND: The use of a simultaneous resection (SIMR) in patients with synchronous colorectal liver metastases (sCRLM) has increased over the past decades. However, it remains unclear when a SIMR is beneficial and when it should be avoided. The aim of this retrospective cohort study was therefore to compare the outcomes of a SIMR for sCRLM in different settings, and to assess which factors are independently associated with unfavorable outcomes. METHODS: To perform this retrospective cohort study, patients with sCRLM undergoing SIMR (2004-2019) were extracted from an international multicenter database, and their outcomes were compared after stratification according to the type of liver and colorectal resection performed. Factors associated with unfavorable outcomes were identified through multivariable logistic regression. RESULTS: Overall, 766 patients were included, encompassing colorectal resections combined with a major liver resection (n=122), minor liver resection in the anterolateral (n=407), or posterosuperior segments ('Technically major', n=237). Minor and technically major resections, compared to major resections, were more often combined with a rectal resection (29.2 and 36.7 vs. 20.5%, respectively, both P=0.003) and performed fully laparoscopic (22.9 and 23.2 vs. 6.6%, respectively, both P = 0.003). Major and technically major resections, compared to minor resections, were more often associated with intraoperative transfusions (42.9 and 38.8 vs. 20%, respectively, both P = 0.003) and unfavorable incidents (9.6 and 9.8 vs. 3.3%, respectively, both P≤0.063). Major resections were associated, compared to minor and technically major resections, with a higher overall morbidity rate (64.8 vs. 50.4 and 49.4%, respectively, both P≤0.024) and a longer length of stay (12 vs. 10 days, both P≤0.042). American Society of Anesthesiologists grades ≥3 [adjusted odds ratio (aOR): 1.671, P=0.015] and undergoing a major liver resection (aOR: 1.788, P=0.047) were independently associated with an increased risk of severe morbidity, while undergoing a left-sided colectomy was associated with a decreased risk (aOR: 0.574, P=0.013). CONCLUSIONS: SIMR should primarily be reserved for sCRLM patients in whom a minor or technically major liver resection would suffice and those requiring a left-sided colectomy. These findings should be confirmed by randomized studies comparing SIMR with staged resections
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