388 research outputs found
Liver cirrhosis, hydroureter and splenomegaly in a cadaver : a case study
Background: Liver cirrhosis is among the most common causes of death in the United States. Cirrhosis can result from alcoholic liver disease, hepatitis, or non-alcoholic fatty liver disease. Advanced cases of liver cirrhosis may result in complications such as portal hypertension, hepatosplenomegaly, varices, and many others.
Case Presentation: This report describes a case of extensive liver cirrhosis found during the cadaveric dissection of a 71-year-old male. Observation revealed a slightly enlarged, cirrhotic liver with recanalization of the umbilical vein (of the round ligament). The patient also had significant splenomegaly, indicative of portal hypertension, and dilation of the left ureter. In developing countries, the leading cause of liver cirrhosis is schistosomiasis. Schistosomiasis has been shown to cause both liver cirrhosis and hydroureter (Genitourinary schistosomiasis, 2012). While this infection cannot be completely ruled out, the likelihood that this was the case in this cadaver is unlikely.
Discussion: Non-invasive and cost-effective options such as serum and imaging tests can prove useful in detecting liver pathology. Detection of early liver disease and intervention can decrease the incidence of advanced complications and prolong life (Smith et al. 2019). In the case of hydroureter, a parasitic infection can be ruled out by laboratory analysis of stool or urine samples by detecting the presence of parasitic eggs. Histological specimens of the liver, ureter, and urinary bladder can be taken to determine if parasitic eggs were present in either of these areas.
Conclusion: This cadaver reveals a classic presentation of portal hypertension that can lead to various secondary pathologies. This case study can be used as additional supporting evidence linking portal hypertension to splenomegaly, hydroureter, and liver cirrhosis
A Drosophila protein-interaction map centered on cell-cycle regulators
BACKGROUND: Maps depicting binary interactions between proteins can be powerful starting points for understanding biological systems. A proven technology for generating such maps is high-throughput yeast two-hybrid screening. In the most extensive screen to date, a Gal4-based two-hybrid system was used recently to detect over 20,000 interactions among Drosophila proteins. Although these data are a valuable resource for insights into protein networks, they cover only a fraction of the expected number of interactions. RESULTS: To complement the Gal4-based interaction data, we used the same set of Drosophila open reading frames to construct arrays for a LexA-based two-hybrid system. We screened the arrays using a novel pooled mating approach, initially focusing on proteins related to cell-cycle regulators. We detected 1,814 reproducible interactions among 488 proteins. The map includes a large number of novel interactions with potential biological significance. Informative regions of the map could be highlighted by searching for paralogous interactions and by clustering proteins on the basis of their interaction profiles. Surprisingly, only 28 interactions were found in common between the LexA- and Gal4-based screens, even though they had similar rates of true positives. CONCLUSIONS: The substantial number of new interactions discovered here supports the conclusion that previous interaction mapping studies were far from complete and that many more interactions remain to be found. Our results indicate that different two-hybrid systems and screening approaches applied to the same proteome can generate more comprehensive datasets with more cross-validated interactions. The cell-cycle map provides a guide for further defining important regulatory networks in Drosophila and other organisms
Early events of Bacillus anthracis germination identified by time-course quantitative proteomics
Germination of Bacillus anthracis spores involves rehydration of the spore interior and rapid degradation of several of the protective layers, including the spore coat. Here, we examine the temporal changes that occur during B. anthracis spore germination using an isobaric tagging system. Over the course of 17 min from the onset of germination, the levels of at least 19 spore proteins significantly decrease. Included are acid-soluble proteins, several known and predicted coat proteins, and proteins of unknown function. Over half of these proteins are small (less than 100 amino acids) and would have been undetectable by conventional gel-based analysis. We also identified 20 proteins, whose levels modestly increased at the later time points when metabolism has likely resumed. Taken together, our data show that isobaric labeling of complex mixtures is particularly effective for temporal studies. Furthermore, we describe a rigorous statistical approach to define relevant changes that takes into account the nature of data obtained from multidimensional protein identification technology coupled with the use of isobaric tags. This study provides an expanded list of the proteins that may be involved in germination of the B. anthracis spore and their relative levels during germination.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55849/1/5199_ftp.pd
Oxidation of Thiols to Disulfides using an Environmentally “Green” Organocatalyst and New Mechanistic Insights
The selective oxidation of thiols to disulfides is an area of great importance in the areas of materials and medicinal chemistry research. The production of polymers, rubber, pharmaceuticals, and the folding of proteins in biological systems all rely on the formation of disulfide bonds. Herein, we introduce a stoichiometric and electrocatalytic method for the oxidation of various pharmaceutically and biologically relevant thiols into their respective disulfides in more environmentally benign solvents such as water and alcohol solvents. The scope of the transformation was evaluated and a detailed mechanistic study involving control experiments, experimental kinetic studies, and computational investigations led to new insights into how the oxidation takes place via an unusual anionic process
Policy Review: Addressing the Complex Challenges of Regulating Biotherapeutics
The advancing industry of biotherapeutics is providing the public with new promising and innovative drugs which may pose risks if their production, distribution, and marketing are not directly governed by legislation. Apart from international agreements, such as the Cartagena Protocol, there are no specific and direct laws or regulations governing manipulated cell-based therapeutics in Canada. The introduction of these laws and regulations in Canada will allow for the safe research and use of biotherapeutics in a proactive manner
Risk assessment – can we achieve consensus?
Objective The object of this conference paper was to review and discuss caries risk assessment in general practice from the questions i) ‘Why’, ii) ‘When’, and iii) ‘How’. Method Narrative review. Results i) Patient caries risk assessment is the basic component in the decision‐making process for adequate prevention and management of dental caries and for determination of individual recall intervals . ii) Caries risk assessment should always be performed at a child's first dental visit and then regularly throughout life, and especially when social or medical life events are occurring. iii) There are several risk assessment methods and models available for but the evidence for their validity is limited. Although there is no clearly superior method for predicting future caries, the use of structured protocols combining socioeconomy, behavior, general health, diet, oral hygiene routines, clinical data, and salivary tests or computer‐based systems are considered best clinical practice. The accuracy ranges between 60% and 90%, depending on age. Caries risk assessment is more effective in the selection of patients at low risk than those with high caries risk. Conclusion As evidence suggests that past caries experience is far from ideal but the most important single risk component for more caries at all ages, any clinical sign of likely active demineralization on smooth, occlusal, and proximal tooth surfaces should be taken as a signal for the implementation of individually designed preventive and disease management measures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96394/1/cdoe12026.pd
Supplemental Vitamins and Minerals for CVD Prevention and Treatment
The authors identified individual randomized controlled trials from previous meta-analyses and additional searches, and then performed meta-analyses on cardiovascular disease outcomes and all-cause mortality. The authors assessed publications from 2012, both before and including the U.S. Preventive Service Task Force review. Their systematic reviews and meta-analyses showed generally moderate- or low-quality evidence for preventive benefits (folic acid for total cardiovascular disease, folic acid and B-vitamins for stroke), no effect (multivitamins, vitamins C, D, β-carotene, calcium, and selenium), or increased risk (antioxidant mixtures and niacin [with a statin] for all-cause mortality). Conclusive evidence for the benefit of any supplement across all dietary backgrounds (including deficiency and sufficiency) was not demonstrated; therefore, any benefits seen must be balanced against possible risks
Sustained proliferation in cancer: mechanisms and novel therapeutic targets
Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression
Functional dissection of siRNA sequence by systematic DNA substitution: modified siRNA with a DNA seed arm is a powerful tool for mammalian gene silencing with significantly reduced off-target effect
Short interfering RNA (siRNA)-based RNA interference (RNAi) is widely used for target gene knockdown in mammalian cells. To clarify the position-dependent functions of ribonucleotides in siRNA, siRNAs with various DNA substitutions were constructed. The following could be simultaneously replaced with DNA without substantial loss of gene-silencing activity: the seed arm, which occupies positions 2–8 from the 5′end of the guide strand; its complementary sequence; the 5′end of the guide strand and the 3′overhang of the passenger strand. However, most part of the 3′ two-thirds of the guide strand could not be replaced with DNA, possibly due to binding of RNA-recognition proteins such as TRBP2 and Ago2. The passenger strand with DNA in the 3′end proximal region was incapable of inducing off-target effect. Owing to lesser stability of DNA–RNA hybrid than RNA duplex, modified siRNAs with DNA substitution in the seed region were, in most cases, incapable to exert unintended gene silencing due to seed sequence homology. Thus, it may be possible to design DNA–RNA chimeras which effectively silence mammalian target genes without silencing unintended genes
Cell Free Expression of hif1α and p21 in Maternal Peripheral Blood as a Marker for Preeclampsia and Fetal Growth Restriction
Preeclampsia, a severe unpredictable complication of pregnancy, occurs in 6% of pregnancies, usually in the second or third trimester. The specific etiology of preeclampsia remains unclear, although the pathophysiological hallmark of this condition appears to be an inadequate blood supply to the placenta. As a result of the impaired placental blood flow, intrauterine growth restriction (IUGR) and consequential fetal oxidative stress may occur. Consistent with this view, pregnancies complicated by preeclampsia and IUGR are characterized by up-regulation of key transcriptional regulators of the hypoxic response including, hif1α and as well as p53 and its target genes. Recently, the presence of circulating cell-free fetal RNA has been documented in maternal plasma. We speculated that pregnancies complicated by preeclampsia and IUGR, will be associated with an abnormal expression of p53 and/or hif1α related genes in the maternal plasma. Maternal plasma from 113 singleton pregnancies (72 normal and 41 complicated pregnancies) and 19 twins (9 normal and 10 complicated pregnancies) were collected and cell free RNA was extracted. The expression of 18 genes was measured by one step real-time RT-PCR and was analyzed for prevalence of positive/negative expression levels. Results indicate that, among the genes examined, cell free plasma expressions of p21 and hif1α were more prevalent in pregnancies complicated by hypoxia and/or IUGR (p<0.001). To conclude, we present in this manuscript data to support the association between two possible surrogate markers of hypoxia and common complications of pregnancy. More work is needed in order to implement these findings in clinical practice
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