Datasets:

knowledgator

/

Scientific-text-classification

like 5

Follow

Knowledgator Engineering 43

Receptor activity-modifying proteins (RAMPs) control the pharmacology of the receptors for the calcitonin family of peptide hormones. There are five of these peptides: calcitonin, calcitonix/calcitixin gene-related peptide (CGRP), adrenomedullin, amylin, and now adrenomedullin 2. The calcitonin receptor is specific for calcitonin when expressed alone but it can function as an amylin or CGRP receptor when co-expressed with a RAMP. The calcitonin receptor-like receptor (CRLR) will not reach the cell surface without any one of the three RAMP proteins to function as either a CGRP or adrenomedullin receptor. This system was discovered more than 6 yr ago. At the time, it was reasonable to think that nature would employ accessory proteins, such as the RAMPs, to enable flexible signaling systems for other ligand families and that these would be discovered in time. In reality, many more new peptide ligands have been discovered than accessory proteins. Why is this? Developments in bioinformatics facilitate the discovery of both seven transmembrane ligands and accessory proteins. Proteomics and transcriptomics can be used together to define likely accessory proteins that can be experimentally tested. Comparative genomics was used in the discovery of adrenomedullin 2. The existence of multiple RAMPs within several species of fish suggests an alternative endocrinology. Finally, genetics offers a direct view of receptors, ligands, and accessory proteins in human disease--either as causative or contributing factors.

Receptors, Adrenomedullin

The development of facile methods for conjugating relevant probes, ligands, or delivery agents onto oligonucleotides (ONs) is highly desirable both for fundamental studies in chemical biology and for improving the pharmacology of ONs in medicinal chemistry. Numerous efforts have been focused on the introduction of bioorthogonal groups onto phosphoramidite building blocks, allowing the controlled chemical synthesis of reactive ONs for postsynthetic modifications. Among these building blocks, alkyne, cyclooctynes, trans-cyclooctene, and norbornene have been proved to be compatible with automated solid-phase chemistry. Herein, we present the development of novel 2'-functionalized nucleoside phosphoramidite monomers comprising bioorthogonal methylcyclopropene or sydnone moieties and their introduction for the first time to ON solid-phase synthesis. Traceless ON postsynthetic modifications with reactive complementary probes were successfully achieved through either inverse electron-demand Diels-Alder (iEDDA) reactions or strain-promoted sydnone-alkyne cycloaddition (SPSAC). These results expand the set of bioorthogonal phosphoramidite building blocks to generate ONs for postsynthetic labeling.

Sydnones

Lipids perform a wide range of functions inside the cell, ranging from structural building block of membranes and energy storage to cell signaling. The mode of action of many signaling lipids has remained elusive due to their low abundance, high lipophilicity, and inherent instability. Various chemical biology approaches, such as photoaffinity or activity-based protein profiling methods, have been employed to shed light on the biological role of lipids and the lipid-protein interaction profile. In this review, we will summarize the recent developments in the field of chemical probes to study lipid biology, especially in immunology, and indicate potential avenues for future research.

Lipids

Phototransformation is an important environmental fate of pesticides on plant leaves. This review found that the photodegradation rates of pesticides on leaves might be faster or slower than those in organic solvents or on glass because of the different spectral patterns and light fluxes on the model surface. Wax was found to play an important role in pesticide phototransformation because it has photosensitizing properties, which might be stimulated under light irradiation to produce reactive species, such as hydroxyl radicals, singlet oxygen, methyl radicals, alkyl radicals, and superoxide radicals. These reactive species could accelerate pesticide photodegradation by several times. Wax can also decrease the photodegradation rate of pesticides by quenching reactive species or light-shielding effects. The environmental conditions and phytochemical properties of leaves play important roles in pesticide phototransformation primarily because the composition of wax varies with plant species and environmental factors. The phototransformation of pesticides on leaves was promoted by a low dosage of adjuvant because they act as photosensitizers and improve the dispersity of pesticides, while it was inhibited at a high concentration of adjuvant because of their light shielding effect. Finally, recommendations for future research were discussed, including (1) distinguishing the direct and indirect photodegradation of pesticides; (2) developing model, molecular level visualization and analysis techniques; (3) conducting more field research; and (4) considering the effect of climate change, especially the interaction of climatic factors. This review gives a comprehensive overview of the current knowledge of pesticide phototransformation on leaves and provides suggestions for future studies.

Superoxides

The structure of the cotton uceA1.7 promoter and its modules was analyzed; the potential of their key sequences has been confirmed in different tissues, proving to be a good candidate for the development of new biotechnological tools. Transcriptional promoters are among the primary genetic engineering elements used to control genes of interest (GOIs) associated with agronomic traits. Cotton uceA1.7 was previously characterized as a constitutive promoter with activity higher than that of the constitutive promoter from the Cauliflower mosaic virus (CaMV) 35S gene in various plant tissues. In this study, we generated Arabidopsis thaliana homozygous events stably overexpressing the gfp reporter gene driven by different modules of the uceA1.7 promoter. The expression level of the reporter gene in different plant tissues and the transcriptional stability of these modules was determined compared to its full-length promoter and the 35S promoter. The full-length uceA1.7 promoter exhibited higher activity in different plant tissues compared to the 35S promoter. Two modules of the promoter produced a low and unstable transcription level compared to the other promoters. The other two modules rich in cis-regulatory elements showed similar activity levels to full-length uceA1.7 and 35S promoters but were less stable. This result suggests the location of a minimal portion of the promoter that is required to initiate transcription properly (the core promoter). Additionally, the full-length uceA1.7 promoter containing the 5'-untranslated region (UTR) is essential for higher transcriptional stability in various plant tissues. These findings confirm the potential use of the full-length uceA1.7 promoter for the development of new biotechnological tools (NBTs) to achieve higher expression levels of GOIs in, for example, the root or flower bud for the efficient control of phytonematodes and pest-insects, respectively, in important crops.

Caulimovirus

The literature on dental erosion is made up of a number of areas, some of which are reviewed here: there are anecdotal case reports, linking a small number of clinical cases with a possible etiological factor. The second area of evidence concentrates on case control studies in which there is a strong association with dental erosion, for example, patients with bulimia. The final piece of epidemiological evidence is beginning to emerge as prevalence studies, but the information from prevalence data worldwide is scanty. It is difficult to compare prevalence studies because of the different indices used in the various studies and also because of the different teeth assessed in the sample. Standardization of indices used would overcome some of these differences as would the reporting of results in a comparable way. However, identifying the true prevalence of erosion per se is fraught with difficulty because there may be more than one etiological factor operating and attrition and or abrasion may complicate the picture, especially in older populations. Case reports frequently associate evidence of erosion with excessive use of particular drinks or foodstuffs so they must be viewed with caution. There is an increasing awareness, amongst the dental profession, of the potential for this particular form of tooth wear to occur. It is important that the dental team is vigilant and instigates preventive measures before tooth tissue loss becomes clinically significant. The importance of erosion in dental health promotion should not be overlooked.

Tooth Erosion

The nef gene is conserved among primate lentiviruses and is one of the first viral genes that is transcribed following infection. This suggests a critical role for Nef in the virus life cycle and in the pathogenesis of lentiviral infections. In vitro, several functions have been described, including down regulation of CD4 and MHC class I surface expression, altered T-cell signaling and activation, and enhanced viral infectivity. However, the impact of these individual functions on viral pathogenicity in general, and thymic T cell production in particular, remains elusive. Here, we review the observations from experimental models that have been used to study the pathogenic effect of HIV-1 Nef on the thymus. These in vitro and in vivo studies have led to a better understanding of Nef's mechanism of action, although there still exists discord as to the contribution of Nef-mediated disturbance of thymopoiesis in the pathogenesis of AIDS.

Gene Products, nef

In mammals, male and female gonads initially develop from bipotential progenitor cells, which can differentiate into either testicular or ovarian cells. The decision to adopt a testicular or ovarian fate relies on robust genetic forces, i.e., activation of the testis-determining gene Sry, as well as a delicate balance of expression levels for pro-testis and pro-ovary factors. Recently, epigenetic regulation has been found to be a key element in activation of Sry. Nevertheless, the mechanism by which epigenetic regulation controls the expression balance of pro-testis and pro-ovary factors remains unclear. Chromodomain Y-like protein (CDYL) is a reader protein for repressive histone H3 methylation marks. We found that a subpopulation of Cdyl-deficient mice exhibited XY sex reversal. Gene expression analysis revealed that the testis-promoting gene Sox9 was downregulated in XY Cdyl-deficient gonads during the sex determination period without affecting Sry expression. Instead, we found that the ovary-promoting gene Wnt4 was derepressed in XY Cdyl-deficient gonads prior to and during the sex-determination period. Wnt4 heterozygous deficiency restored SOX9 expression in Cdyl-deficient XY gonads, indicating that derepressed Wnt4 is a cause of the repression of Sox9. We found that CDYL directly bound to the Wnt4 promoter and maintained its H3K27me3 levels during the sex-determination period. These findings indicate that CDYL reinforces male gonadal sex determination by repressing the ovary-promoting pathway in mice.

Wnt4 Protein

BACKGROUND: Septic abortion is an infection of the uterus and its appendages following any abortion especially, illegally performed induced abortions. It is characterized by a rise of temperature to at least 100.4 degrees F, associated offensive or purulent vaginal discharge and lower abdominal pain and tenderness. AIM: To study maternal mortality and morbidity in induced septic abortions. METHODS: Induced septic abortions were analyzed between April 1992 and September 1999 in TU Teaching hospital. Morbidity indicators were surgery other than curettage, prolonged hospitalization and permanent damage. RESULTS: In 92 cases of induced septic abortions, comprising 6% of total abortions; nine deaths occurred because of disseminated intravascular coagulation, acute renal failure and adult respiratory distress syndrome. Vaginal, intraperitoneal and gum bleeding; epistaxis and malaena resulted in severe anemia (Hb < 6 gm/L) in 11 cases. Wound debridement and skin graft cured two cases of necrotizing fasciitis. One of four conservatively managed tubo-ovarian masses spontaneously drained rectally. In 15 cases laparotomy for pus drainage, salpingectomy, salpingo-oophorectomy, hysterotomy/uterine rent repair was conducted, along with four bowel surgeries and six hysterectomies were performed. Post-operative complications included burst abdomen (one case) and reopened pyoperitoneum, which resulted fecal fistula in three cases, one of these patients died. CONCLUSION: : Induced abortion was proven to be a major detrimental factor for maternal mortality. Morbidity was four times higher than mortality to the extent that patients suffered hemiplegia and forced barrenness.

Abortion, Septic

PURPOSE: To evaluate the importance of esophageal abnormalities as a potential cause of recurrent noncardiac chest pain. DATA IDENTIFICATION: We discuss the rapidly evolving new knowledge in this field after analyzing the literature in English published since 1979. STUDY SELECTION: We reviewed 117 articles on recurring chest pain and paid specific attention to the following nine controversial issues: the potential mechanisms of esophageal pain, the differentiation of cardiac and esophageal causes, the evaluation of new esophageal motility disorders, the use of esophageal tests in evaluating noncardiac chest pain, the usefulness of techniques for prolonged monitoring of intraesophageal pressure and pH, the relation of psychologic abnormalities to esophageal motility disorders, the possible mechanisms for decreased visceral pain thresholds in these patients, the relation of esophageal chest pain to the irritable bowel syndrome, and the appropriate therapies for these patients. RESULTS OF DATA SYNTHESIS: Through our review of the literature, we identified areas of concordance and disagreement. These areas are discussed and an overall perspective is provided. CONCLUSIONS: Continuing attempts to develop rational diagnostic and therapeutic approaches to patients with noncardiac chest pain should include a multidisciplinary approach involving basic scientists, gastroenterologists, psychologists, and other clinical experts in the field of pain research.

Esophageal Diseases

Spanish Cedar (Cedrela odorata L.) is a globally important timber species which has been severely exploited in Mesoamerica for over 200 years. Using polymerase chain reaction-restriction fragment length polymorphisms, its chloroplast (cp) DNA phylogeography was studied in Mesoamerica with samples from 29 populations in six countries. Five haplotypes were characterized, phylogenetically grouped into three lineages (Northern, Central and Southern). Spatial analysis of ordered genetic distance confirmed deviation from a pattern of isolation by distance. The geographically proximate Northern and Central cpDNA lineages were genetically the most differentiated, with the Southern lineage appearing between them on a minimum spanning tree. However, populations possessing Southern lineage haplotypes occupy distinct moist habitats, in contrast to populations possessing Northern and Central lineage haplotypes which occupy drier and more seasonal habitats. Given the known colonization of the proto-Mesoamerican peninsula by South American flora and fauna prior to the formation of the Isthmus of Panama, it seems most likely that the observed population structure in C. odorata results from repeated colonization of Mesoamerica from South American source populations. Such a model would imply an ancient, pre-Isthmian colonization of a dry-adapted type (possessing the Northern lineage or a prototype thereof), with a secondary colonization via the land bridge. Following this, a more recent (possibly post-Pleistocene) expansion of moist-adapted types possessing the Southern lineage from the south fits the known vegetation history of the region.

Cedrela

DNA-protein cross-linkages were performed in intact undifferentiated and differentiated-HL60 cells by the action of cis-diammine dichloroplatinum. Total nuclear matrix proteins and DNA cross-linked nuclear matrix proteins were resolved by two-dimensional gel electrophoresis. The comparison of the electrophoretic patterns allowed the identification of a set of differentiation-induced nuclear matrix proteins cross-linked to DNA. One of these proteins binds cloned histone SAR sequences. Our results outline an experimental strategy for isolating and characterizing nuclear matrix components that may play a fundamental role in the overall control and coordination of gene expression during differentiation.

Nuclear Proteins

The development of cross-sectional imaging techniques has enhanced the detection of pancreatic cystic lesions (PCLs). PCLs are found in approximately 2% of the general population, often as incidentally detected lesions on computed tomography or MRI during the evaluation of other medical conditions. Broadly, PCLs are classified as mucinous or nonmucinous. Mucinous PCLs include mucinous cystic neoplasms and intraductal papillary mucinous neoplasms. Nonmucinous PCLs include pseudocysts, serous cystadenomas, solid pseudopapillary neoplasms, and cystic pancreatic neuroendocrine tumors, as well as cystic acinar cell carcinoma, cystic degeneration of pancreatic ductal adenocarcinoma, lymphoepithelial cyst, and others.

Cystadenoma, Serous

BACKGROUND: The literature contains little information about the incidence or prevalence of oral signs in psoriasis. The pustular forms are the most commonly incriminated, with geographic tongue being the most frequently cited oral sign. The aim of our study was to determine the various types of oral signs seen in a large population of psoriasis patients. PATIENTS AND METHODS: Four hundred psoriasis patients were recruited consecutively and a detailed oral examination performed by two clinicians. Similar examinations were performed over the same period in 1000 nonpsoriasis subjects comprising a control group in order to assess the incidence of the same oral signs in the general population. RESULTS: Comparing the two groups, fissured tongue was seen in 33.2% of psoriasis patients versus 9.9% of control subjects (P<0.0001). There was thus a highly significant (P<0.0001) correlation between geographic tongue and psoriasis (7.7% of psoriasis patients versus 1% of controls). In addition, a strong correlation was seen between the presence of pustular psoriasis and fissured tongue (83.3% of patients with pustular psoriasis versus only 30% of patients with other forms of psoriasis). DISCUSSION: Our study shows a strong correlation between psoriasis and fissured and geographic tongue, although these features are not pathognomonic for the disease. As regards geographic tongue, our results are consistent with the data in the literature. However, the prevalence of fissured tongue was considerably higher among our patients than in series published to date. These two types of sign involving the tongue, and which can occur in all forms of psoriasis, appear to be particularly strongly associated with pustular psoriasis. Patients are generally unaware of this sign and rarely complain of it.

Glossitis, Benign Migratory

Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species.

Pseudotsuga

Drug-induced QTc prolongation is a concerning electrocardiogram (ECG) abnormality. This cardiac disturbance carries a 10% risk of sudden cardiac death due to the malignant arrhythmia, Torsades de Pointes. The Arizona Center for Education and Research on Therapeutics (AzCERT) has classified QTc prolonging therapeutic classes, such as antiarrhythmics, antipsychotics, anti-infectives, and others. AzCERT criteria categorize medications into three risk categories: known," "possible," and "conditional risk" of QTc prolongation and Torsades de Pointes. The list of QTc prolonging medications continues to expand as new drug classes are approved and studied. Risk factors for QTc prolongation can be delineated into modifiable or non-modifiable. A validated risk scoring tool may be utilized to predict the likelihood of prolongation in patients receiving AzCERT classified medication. The resultant risk score may be applied to a clinical decision support system, which offers mitigation strategies. Mitigation strategies including discontinuation of possible offending agents with a selection of an alternative agent, assessment of potential drug interactions or dose adjustments through pharmacokinetic and pharmacodynamic monitoring, and initiation of both ECG and electrolyte monitoring are essential to prevent a drug-induced arrhythmia. The challenges presented by the COVID-19 pandemic have led to the development of innovative continuous monitoring technology, increasing protection for both patients and healthcare workers. Early intervention strategies may reduce adverse events and improve clinical outcomes in patients identified to be at risk of QTc prolongation."

Torsades de Pointes

Several members of a widespread class of bacterial and archaeal metalloflavoproteins, called FprA, likely function as scavenging nitric oxide reductases (S-NORs). However, the only published X-ray crystal structure of an FprA is for a protein characterized as a rubredoxin:dioxygen oxidoreductase (ROO) from Desulfovibrio gigas. Therefore, the crystal structure of Moorella thermoacetica FprA, which has been established to function as an S-NOR, was solved in three different states: as isolated, reduced, and reduced, NO-reacted. As is the case for D. gigas ROO, the M. thermoacetica FprA contains a solvent-bridged non-heme, non-sulfur diiron site with five-coordinate iron centers bridged by an aspartate, and terminal glutamate, aspartate, and histidine ligands. However, the M. thermoacetica FprA diiron site showed four His ligands, two to each iron, in all three states, whereas the D. gigas ROO diiron site was reported to contain only three His ligands, even though the fourth His residue is conserved. The Fe1-Fe2 distance within the diiron site of M. thermoacetica FprA remained at 3.2-3.4 A with little or no movement of the protein ligands in the three different states and with conservation of the two proximal open coordination sites. Molecular modeling indicated that each open coordination site can accommodate an end-on NO. This relatively rigid and symmetrical diiron site structure is consistent with formation of a diferrous dinitrosyl as the committed catalytic intermediate leading to formation of N(2)O. These results provide new insight into the structural features that fine-tune biological non-heme diiron sites for dioxygen activation vs nitric oxide reduction.

Desulfovibrio gigas

Catalytic antibodies (CAbs) occur naturally in healthy individuals where they may form part of the innate immune system, but are preferentially found in those with autoimmune disease. CAbs can also be artificially engineered or elicited by immunizations. Their mechanisms of action include nucleophilic catalysis, induction of conformational strain, coordination with metal ions, and stabilization of transition states. Recent applications of CAbs with clinical significance include the conversion of cocaine to a non-psychoactive form, the degradation of nicotine, activation of prodrugs for targeted chemotherapy, protection from ultraviolet radiation, inhibition of HIV infectivity, and the destruction of aggregates of beta-amyloid implicated in Alzheimer's disease. Artificial CAbs are likely to find increasing applications in research, clinical medicine, diagnostics and manufacturing.

Antibodies, Catalytic

Story telling is a fundamental part of clinical practice. It provides the mechanism by which doctors and patients communicate and understand the meaning of illness and possible ways of dealing with it. Humour is a particular aspect of story telling and, while there are some negative aspects, generally does have a therapeutic benefit. The physiological effects of laughter are considerable. Both story telling and humour are important for learning and are complementary to the more formal learning from text books and lectures. Stories assist in the development of emotional knowledge. The hypothesis of the contagious theory of behaviour change is presented as a way in which ideas are transmitted from one person to another.

Wit and Humor as Topic

Three new Daphniphyllum alkaloids, calyciphyllines N-P (1-3), were isolated from the leaves and stems of Daphniphyllum calycinum. The structures and relative stereochemistry of 1-3 were elucidated on the basis of spectroscopic data.

Saxifragaceae

OBJECTIVE: To assess the technical efficiency of traditional public hospitals without their own legal identity and subject to administrative law, and that of public enterprise hospitals, with their own legal identities and partly governed by private law, all of them belonging to the taxypayer-funded health system of Andalusia during the period 2005 -2008. METHODS: The study included the 32 publicly-owned hospitals in Andalusia during the period 2005-2008. The method consisted of two stages. In the first stage, the indices of technical efficiency of the hospitals were calculated using Data Envelopment Analysis, and the change in total factor productivity was estimated using the Malmquist index. The results were compared according to perceived quality, and a sensitivity analysis was conducted through an auxiliary model and bootstrapping. In the second stage, a bivariate analysis was performed between hospital efficiency and organization type. RESULTS: Public enterprises were more efficient than traditional hospitals (on average by over 10%) in each of the study years. Nevertheless, a process of convergence was observed between the two types of organizations because, while the efficiency of traditional hospitals increased slightly (by 0.50%) over the study period, the performance of public enterprises declined by over 2%. DISCUSSION: The possible reasons for the greater efficiency of public enterprises include their greater budgetary and employment flexibility. However, the convergence process observed points to a process of mutual learning that is not necessarily efficient.

Efficiency

The fish fin is a breathtaking repository full of evolutionary diversity, novelty, and convergence. Over 500 million years, the adaptation to novel habitats has provided landscapes of fin diversity. Although comparative anatomy of evolutionarily divergent patterns over centuries has highlighted the fundamental architectures and evolutionary trends of fins, including convergent evolution, the developmental constraints on fin evolution, which bias the evolutionary trajectories of fin morphology, largely remain elusive. Here, we review the evolutionary history, developmental mechanisms, and evolutionary underpinnings of paired fins, illuminating possible developmental constraints on fin evolution. Our compilation of anatomical and genetic knowledge of fin development sheds light on the canalized and the unpredictable aspects of fin shape in evolution. Leveraged by an arsenal of genomic and genetic tools within the working arena of spectacular fin diversity, evolutionary developmental biology embarks on the establishment of conceptual framework for developmental constraints, previously enigmatic properties of evolution.

Animal Fins

Biliary cystic disease is uncommon in Asia and very rare in Europe and the Americas. Patients with biliary cysts may present as infants, children, or adults. When patients present as adults, they are more likely to have stones in the gallbladder, common duct, or intrahepatic ducts and to present with biliary colic, acute cholecystitis, cholangitis, or gallstone pancreatitis. With increasing age at presentation, the risks of intrahepatic strictures and stones, segmented hepatic atrophy/hypertrophy, secondary biliary cirrhosis, portal hypertension, and biliary malignancy all increase significantly. Factors to be considered when performing surgery on patients with biliary cystic disease include: (1) age, (2) presenting symptoms, (3) cyst type, (4) associated biliary stones, (5) prior biliary surgery, (6) intrahepatic strictures, (7) hepatic atrophy/hypertrophy, (8) biliary cirrhosis, (9) portal hypertension, and (10) associated biliary malignancy. In general, regardless of age, presenting symptoms, biliary stones, prior surgery or other secondary problems, surgery should include cholecystectomy and excision of extrahepatic cyst(s). With respect to the distal bile duct, the surgical principle should be excision of a portion of the intrapancreatic bile duct with care to not injure the pancreatic duct or a long common channel. Resection of the pancreatic head should be reserved for patients with an established malignancy. With respect to the intrahepatic ducts, surgery should be individualized depending on whether (1) both lobes are involved, (2) strictures and stones are present, (3) cirrhosis has developed, or (4) an associated malignancy is localized or metastatic. When the liver is not cirrhotic, hepatic parenchyma should be preserved even when strictures and stones are present. If cirrhosis is advanced, hepatic transplantation may be indicated, but this sequence of events is unusual. If a malignancy has developed, oncologic principles should be followed. Whenever possible, resection of a localized tumor including adjacent hepatic parenchyma and regional lymph nodes should be performed."

Digestive System Abnormalities

The pharmaceutical relevance of proton-coupled peptide transporters is currently under intense investigation in many laboratories. Studies have shown that these membrane proteins, expressed in intestine, kidney, choroid plexus and other tissues, accept many peptidomimetic drugs and prodrugs as substrates. The focus of this review is on the interaction of beta-lactam antibiotics, angiotensin-converting enzyme inhibitors, sartans and other drugs with PEPT1 and PEPT2. The article highlights progress made in recent years and the most expedient techniques that have been or are being employed. It also emphasizes the opportunities in rational drug design that are of highest priority and the pitfalls that must be avoided. Finally, an instructional flowchart that might be used to identify a peptide transporter substrate is proposed.

Peptide Transporter 1

We tested the hypothesis that changes in sodium intake modulate adipose-tissue renin-angiotensin and natriuretic peptide system gene expression in humans. We studied 9 healthy young men in a metabolic ward at constant room temperature, humidity, and water, potassium, and calcium intake. Subjects were submitted to 4 different periods of sodium intake, and blood samples, microdialysis samples (interstitial fluid), and biopsies from subcutaneous abdominal adipose tissue were obtained at the end of the low-sodium period (0.7 mmol Na/kg per day) and at the end of the high-sodium period (7.7 mmol Na/kg per day). Urinary sodium excretion was 64+/-4 mmol per day with the low-sodium diet and 521+/-8 mmol per day with the high-sodium diet. Systemic and microdialysate sodium concentrations were similar with both interventions. With high-sodium intake, systemic renin activity and aldosterone levels were suppressed, angiotensin-converting enzyme activity did not change, and systemic levels of the atrial natriuretic peptide increased. High-sodium diet increased angiotensin-converting enzyme and atrial natriuretic peptide gene expression in adipose tissue. None of the other genes tested were influenced by changes in dietary sodium intake. Our findings suggest that the adipose-tissue renin-angiotensin system is not part of a feedback mechanism regulating sodium homeostasis and blood pressure. Systemic and adipose-tissue renin-angiotensin systems are regulated at least in part independently from each other. In contrast, systemic atrial natriuretic peptide and adipose-tissue atrial natriuretic peptide respond similarly to changes in sodium intake.

Renin-Angiotensin System

This paper comments on five articles in the special issue Circulating Images in the Life Sciences." It sees the papers as unified by two themes. The first is their attention to the processes of legitimation. The second is the embedding of the images in textual cultures, which changed over time from the mid-nineteenth century to the very recent past, most notably with the recent advent of digital culture."

Light Signal Transduction

Buffer catalysis of the cleavage and isomerization of uridylyl-3',5'-uridine (UpU) has been studied over a wide pH range in 80% aq. DMSO. The diminished hydroxide ion concentration in this solvent system made catalysis by amine buffers (morpholine, 4-hydroxypiperidine and piperidine) visible even at relatively low buffer concentrations (10-200 mmol L(-1)). The observed catalysis was, however, much weaker than what has been previously reported for the activated RNA model 2-hydroxypropyl 4-nitrophenyl phosphate (HPNP) in the same solvent system. In the case of morpholine, contribution of both the acidic and the basic buffer constituent was significant, whereas with 4-hydroxypiperidine and piperidine participation of the acidic constituent could not be established unambiguously. The results underline the importance of using realistic model compounds, along with activated ones, in the study of the general acid/base catalysis of RNA cleavage.

Uridine

Sialic acids (Sias) are a group of alpha-keto acids with a nine-carbon backbone, which display many types of modifications in nature. The diversity of natural Sia presentations is magnified by a variety of glycosidic linkages to underlying glycans, the sequences and classes of such glycans, as well as the spatial organization of Sias with their surroundings. This diversity is closely linked to the numerous and varied biological functions of Sias. Relatively large libraries of natural and unnatural Sias have recently been chemically/chemoenzymatically synthesized and/or isolated from natural sources. The resulting sialoglycan microarrays have proved to be valuable tools for the exploration of diversity and biology of Sias. Here we provide an overview of Sia diversity in nature, the approaches used to generate sialoglycan microarrays, and the achievements and challenges arising.

Sialic Acids

This paper describes isolation and identification of a virus (termed strain 87A) which has the cytopathic effect and haemagglutination properties of hepatitis E virus (HEV). This virus was isolated by tissue culture from the faeces of a patient with acute non-A, non-B enteric hepatitis in Xinjiang, China. The isolated virus was neutralized by acute phase sera obtained from other patients with acute non-A, non-B enteric hepatitis. The virus particles also could be specifically aggregated with acute phase sera from patients with known HEV hepatitis in China, Burma, India and the U.S.S.R., and with acute and convalescent sera from an HEV-infected chimpanzee. Crystalline arrangements of virus particles in the cytoplasm were observed by electron microscopy in ultrathin sections of infected cells. The sedimentation coefficient of the strain 87A virus particles in sucrose gradients was 176S. Purified virus particles revealed a protein band of about 76K on SDS-PAGE and Western blotting. The evidence indicates that the strain 87A virus is an HEV. Our ability to propagate HEV in cell culture should facilitate research on this hepatotropic virus.

Hepatitis E virus

Embryonic stem (ES) cells are derived from the inner cell mass of the blastocyst and can be cultured as three-dimensional embryoid bodies (EBs) in which embryonic pregastrulation stages are faithfully mimicked. Fibroblast growth factor receptors (mainly FGFR2) are involved in the first differentiation events during early mammalian embryogenesis. It has been demonstrated that the presence of FGFR2 is a prerequisite for laminin-111 and collagen type IV synthesis and subsequently basement membrane formation in EBs. To identify genes that are influenced by FGFR signalling, we performed global gene expression profiling of differentiating EBs expressing dominant negative FGFR2 (dnFGFR2), acquiring an extensive catalogue of down- and up-regulated genes. We show a strong down-regulation of endodermal and basement membrane related genes, which strengthen the view that the FGFR signalling pathway is a main stimulator of basement membrane synthesis in EBs. We further present down-regulation of genes previously not linked to FGFR signalling, and in addition an active transcription of some mesodermal related genes in differentiating dnFGFR2 EBs."

Receptor, Fibroblast Growth Factor, Type 2

Diseases of the respiratory system are known to negatively impact the profitability of the pig industry, worldwide. Considering the relatively short lifespan of pigs, lesions can be still evident at slaughter, where they can be usefully recorded and scored. Therefore, the slaughterhouse represents a key check-point to assess the health status of pigs, providing unique and valuable feedback to the farm, as well as an important source of data for epidemiological studies. Although relevant, scoring lesions in slaughtered pigs represents a very time-consuming and costly activity, thus making difficult their systematic recording. The present study has been carried out to train a convolutional neural network-based system to automatically score pleurisy in slaughtered pigs. The automation of such a process would be extremely helpful to enable a systematic examination of all slaughtered livestock. Overall, our data indicate that the proposed system is well able to differentiate half carcasses affected with pleurisy from healthy ones, with an overall accuracy of 85.5%. The system was better able to recognize severely affected half carcasses as compared with those showing less severe lesions. The training of convolutional neural networks to identify and score pneumonia, on the one hand, and the achievement of trials in large capacity slaughterhouses, on the other, represent the natural pursuance of the present study. As a result, convolutional neural network-based technologies could provide a fast and cheap tool to systematically record lesions in slaughtered pigs, thus supplying an enormous amount of useful data to all stakeholders in the pig industry.

Pleurisy