An Evolutionary Scenario For The Origin Of Pentaradial Echinoderms—Implications From The Hydraulic Principles Of Form Determination

The early evolutionary history of echinoderms was reconstructed on the basis of structural-functional considerations and application of the quasi-engineering approach of ‘Konstruktions-Morphologie’. According to the presented evolutionary scenario, a bilaterally symmetrical ancestor, such as an enteropneust-like organism, became gradually modified into a pentaradial echinoderm by passing through an intermediate pterobranch-like stage. The arms of a pentaradial echinoderm are identified as hydraulic outgrowths from the central coelomic cavity of the bilateral ancestor which developed due to a shortening of the body in length but widening in the diameter. The resulting pentaradial symmetry is a consequence of mechanical laws that dictate minimal contact surface areas among hydraulic pneumatic entities. These developed in the coelomic cavity (metacoel) in the bilaterally symmetrical ancestor, when from the already U-shaped mesentery with the intestinal tract two additional U-shaped bows developed directly or subsequently. During the subsequent development tensile chords of the mesentery ‘sewed’ the gut with the body wall first in three and secondly in five ‘seams’. During the direct development five ‘seams’ between tensile chords and body wall developed straightly. These internal tensile chords subdivide the body coelom into five hydraulic subsystems (‘pneus’), which eventually arrange in a pentaradial pattern. The body could then enlarge only between the tensile chords, which means that five hydraulic bulges developed. These bulges initially supported the tentacles and finally each of them enclosed the tentacle until only the feather-like appendages of the tentacles projected over the surface. The tentacles with their feathers were transformedinto the ambulacral system, and the bulges become the arms. These morphological transformations were accompanied and partly determined by specific histological modifications, such as the development of mutable connective tissues and skeletal elements that fused to ossicles and provided shape stabilization in form of a calcareous skeleton in the body wall. The organism resulted was an ancestral echinoderm (‘Ur-Echinoderm’) with an enlarged metacoel, stabilized by hydraulic pressure working againsta capsule of mutable connective tissue, skeletal elements and longitudinal muscles. In regard to these reconstructions, the body structure of echinoderms can be understood as a hydraulic skeletal capsule.     

The Use Of Lead Tetraacetate,Benzidine, O-Dianisidine and A “Film Test” In Investigating The Periodic-Acid-Schiff Technic

In order to obtain a better understanding of the “periodic-acid-Schiff” reaction, also known as the “periodic-acid fuchsin-sulfurous-acid” reaction, three types of investigations were carried out

1) The Schiff reagent was replaced by other aldehyde reagents: benzidine or o-dianisidine. There was no significant change in the histological distribution and intensity of the reactions occurring after periodic acid oxidation.

2) Periodic acid was replaced by another oxidizing agent: lead tetraacetate (dissolved in acetic acid). There was no significant change in the histological distribution of the reactions with the Schiff reagent, but some change in their intensity. It was concluded that 1,2-glycols and a-amino alcohols play the main role in the reactions with both oxidants. The presence of α-hydroxy acids in some types of mucous cells is suggested by the results with lead tetraacetate.

Incidently, glycogen and starch are not sufficiently oxidized by lead tetraacetate (in acetic acid) at room temperature to give positive reactions with the Schiff reagent, while cellulose and other periodic-acid-Schiff reactive substances are.

3) The staining of films of presumed reactive substances with the periodic-acid-Schiff technic C O the intense reactivity of many polysaccharides, mucopolysaccharides and mucoproteins, but not of ordinary proteins. (Hyaluronic and chondroitin sulfuric acid are, however, not reactive in vitro).

In conclusion, the periodic-acid-Schiff technic consists of an oxidation of 1,2-glycols and a-amino alcohols to produce aldehyde groups, which are then stained by the Schiff reagent. The “film test” reveals that these radicals are present in certain polysaccharides, mucopolysaccharides and mucoproteins.     

An Improved Method for The Preparation Of The Phosphoramidites Of Modified 2′-Deoxynucleotides: Incorporation Of 8-Oxo-2′-Deoxy-7H-Guanosine Into Synthetic Oligomers

Abstract

3′ -O-(Diisopropylamino-2-cyanoethoxyphosphinyl)-5′ -0-(4, 4′ -dimethoxytrityl)-N²-isobutyryl-8-oxo-2′-deoxy-7H-guanosine was synthesized and used for the introduction of an 8?0×0?2′-deoxy-7H-guanosine residue into a DNA oligomer by means of automated synthesis. A modification of the preparation of the phosphoramidite markedly improves the coupling efficiency in the oligomer synthesis in this and several other cases that were tested.     

Hyperinsulinemia Associated With Acanthosis Nigricans,Finger Pebbles,Acrochordons, And The Sign Of Leser-Trélat

ObjectiveTo review common skin manifestations associated with type 2 diabetes mellitus (DM), and to discuss a potential underlying mechanism for these manifestations.MethodsA PubMed literature search was conducted for articles describing the skin manifestations associated with hyperinsulinemia and type 2 DM. A case presentation describes a morbidly obese patient with type 2 DM treated with metformin who developed acanthosis nigricans, finger pebbles, scores of skin tags (acrochordons), and the sign of LeserTrelat (sudden onset shower of seborrheic keratoses) in the absence of internal malignancy.ResultsAcanthosis nigricans, acrochordons, and finger pebbles have been associated with type 2 DM and obesity. While the LeserTrelat sign is classically associated with internal malignancy, it can also be idiopathic. To our knowledge, this the first report of the occurrence of the LeserTrelat sign in a patient with DM absent internal malignancy.ConclusionSeveral skin manifestations can be seen in this patient with DM because of underlying insulin resistance and subsequent stimulation of insulinlike growth factor receptors. Management strategies could include weight loss, diet, and insulinsensitizing pharmacologic therapy. (Endocr Pract. 2013;19:522525)     

Of fat, β cells, and diabetes

The molecular mechanisms linking diet, obesity, and type 2 diabetes are still poorly understood. In a recent paper, Ohtsubo et?al. (2011) show that high lipid levels induce nuclear exclusion of Foxa2 and HNF1α in β cells, leading to impaired expression and glycosylation of proteins controlling glucose-stimulated insulin secretion.     

Presidential Address—Some Reflections On The Nature Of Species

Background: Variation in the distribution and abundance of woody plants as consequence of disturbances such as fire may be explained by lineage age.

Aims: We tested whether lowland tropical tree lineages that colonise secondary forests are more late-diverging than clades from old-growth forests, and whether tree phylogenetic beta diversity from old-growth to secondary forests is higher in burned than non-burned secondary forests.

Methods: We sampled tree communities in old-growth forests and in secondary forests with distinct disturbance histories (burned and unburned). We calculated mean family age in each plot, and tested for differences among forest types using ANOVA. A phylogenetic fuzzy-weighting procedure was employed to generate a matrix describing the abundance of tree clades per plot, which was then analysed using a principal coordinate analysis.

Results: Most clades found in old-growth forests were underrepresented in secondary forests, which have been heavily colonised by a single species from a young lineage that is not found in old-growth forests. Phylogenetic beta diversity was higher between unburned secondary forests and old-growth forests than between burned secondary forests and old-growth forests.

Conclusions: The capacity of Neotropical trees to colonise secondary forests and persist after fire disturbance may be related to the age of distinct lineages.     

Consensus Statement By The American Association Of Clinical Endocrinologists And American College Of Endocrinology On The Comprehensive Type 2 Diabetes Management Algorithm – 2016 EXECUTIVE SUMMARY

Abbreviations:A1C = hemoglobin A1CAACE = American Association of Clinical EndocrinologistsACCORD = Action to Control Cardiovascular Risk in DiabetesACCORD BP = Action to Control Cardiovascular Risk in Diabetes Blood PressureACEI = angiotensinconverting enzyme inhibitorAGI = alpha-glucosidase inhibitorapo B = apolipoprotein BARB = angiotensin II receptor blockerASCVD = atherosclerotic cardiovascular diseaseBAS = bile acid sequestrantBMI = body mass indexBP = blood pressureCHD = coronary heart diseaseCKD = chronic kidney diseaseCVD = cardiovascular diseaseDKA = diabetic ketoacidosisDPP-4 = dipeptidyl peptidase 4EPA = eicosapentaenoic acidFDA = Food and Drug AdministrationGLP-1 = glucagon-like peptide 1HDL-C = high-density-lipoprotein cholesterolLDL-C = low-densitylipoprotein cholesterolLDL-P = low-density-lipoprotein particleLook AHEAD = Look Action for Health in DiabetesNPH = neutral protamine HagedornOSA = obstructive sleep apneaSFU = sulfonylureaSGLT-2 = sodium glucose cotransporter-2SMBG = self-monitoring of blood glucoseT2D = type 2 diabetesTZD = thiazolidinedione     

The Landscape Of Alpha Fetoprotein In Hepatocellular Carcinoma: Where Are We?

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and has been acknowledged as a leading cause of death among cirrhosis patients. Difficulties in early diagnosis and heterogeneity are obstacles to effective treatment, especially for advanced HCC. Liver transplantation (LT) is considered the best therapy for HCC. Although many biomarkers are being proposed, alpha-fetoprotein (AFP), which was identified over 60 years ago, remains the most utilized. Recently, much hope has been placed in the immunogenicity of AFP to develop novel therapies, such as AFP vaccines and AFP-specific adoptive T-cell transfer (ACT). This review summarizes the performance of AFP as a biomarker for HCC diagnosis and prognosis, as well as its correlation with molecular classes. In addition, the role of AFP in LT is also described. Finally, we highlight the mechanism and application prospects of two immune therapies (AFP vaccine and ACT) for HCC. In general, our review points out the prevalence of AFP in HCC, accompanied by some controversies and novel directions for future research.     

Translation And Cultural Adaptation Of A Mental Health Outcome Measure: The Basis-R©

Culturally and linguistically appropriate outcome measures are needed to address the needs of Latino consumers of mental health services. The revised Behavior and Symptom Identification Scale (BASIS-R(c)) is an English-language consumer self-report measure designed to assess outcome of behavioral health or substance abuse treatment. This study sought to develop a culturally and linguistically appropriate version of the BASIS-R(c) for Spanish-speaking Latinos. To achieve this goal, the English instrument was translated and adapted into Spanish by an international bilingual committee and tested in four focus groups and 45 cognitive interviews with Puerto Ricans, Dominicans, and Mexicans living in the United States and Puerto Rico. Focus groups and cognitive interviews provided qualitative and quantitative information about the instrument's content and format, and respondents' understanding of the instructions, questionnaire items, time frame, and response options. Respondents' ratings of the clarity and importance of each item were also obtained. Analyses of focus group and cognitive interview data identified items that were confusing or difficult for participants. Findings suggest that the Spanish version of the BASIS-R(c) incorporated the cultural diversity of the three groups of Latinos in this study without compromising the validity of the English version of the BASIS.     

Of lice and men: The return of the ’comparative parasitology‘ debate

The question of whether or not parasite phylogeny provides information about host relationships (‘comparative parasitology’) reached a peak in 1957 in a vigorous debate between Gunther Timmermann and Ernst Mayr. Timmermann argued that parasites were associated with their hosts by descent and that this produced congruent host and parasite phylogenies. In contrast, Mayr argued that parasites were often associated by colonization and that this led to incongruence between host and parasite phylogenies. To test these differing views. Adrian Paterson, Russell Gray and Graham Wallis derived a procellaniform phylogeny. This tree is here compared with Timmermann's tree based on the relationships of feather lice. Timmermann's tree is more similar to the seabird phylogeny than would be expected by chance. Thus, support is found for the ‘comparative parasitology’ approach.     

Actigraphic Investigations On The Activity‐Rest Behavior Of Right‐ and Left‐Handed Students

The aim of this study was to explore differences between left‐and right‐handed subjects in sleep duration. Sleep and activity patterns were continuously registered for 12 days using actometers on 20 left‐handed and 20 right‐handed medical students in Berlin. Handedness was determined by a modified version of the Edinburgh handedness inventory. Each participant wore one actometer on each wrist. Actiwatch® Sleep Analysis Software (CNT, UK) was used to evaluate the data, and statistical calculations were performed with a non‐parametric variance analysis. A significant difference in mean sleep duration between left‐handers (7.9 h) and right‐handers (7.3 h) was determined (p=0.025 for measurement made on the dominant hand and p=0.013 for ones made on the non‐dominant hand). In contrast, the maximal phase of daily activity (acrophase) did not show any difference between the two groups. The difference in sleep duration might be caused by either the greater effort required for left‐handers to cope in a right‐handed world or by structural brain differences.     

The Structure And Synthetic Capabilities Of A Catalytic Peptide Formed By Substrate-Directed Mechanism – Implications To Prebiotic Catalysis

Previously, we have shown that a small substrate may serve as a template in the formation of a specific catalytic peptide, a phenomenon which might have had a major role in prebiotic synthesis of peptide catalysts. This was demonstrated experimentally by the formation of a catalytic metallo-dipeptide, Cys₂-Fe²⁺, around o-nitrophenyl β-D-galactopyranoside (ONPG), by dicyandiamide (DCDA)-assisted condensation under aqueous conditions. This dipeptide was capable of hydrolyzing ONPG at a specific activity lower only 1000 fold than that of β galactosidase. In the present paper we use molecular modeling techniques to elucidate the structure of this catalyst and its complex with the substrate and propose a putative mechanism for the catalyst formation and its mode of action as a “mini enzyme”. This model suggests that interaction of Fe²⁺ ion with ONPG oxygens and with two cysteine SH groups promotes the specific formation of the Cys₂-Fe²⁺ catalyst. Similarly, the interaction of the catalyst with ONPG is mediated by its Fe²⁺ with the substrate oxygens, leading to its hydrolysis. In addition, immobilized forms of the catalyst were synthesized on two carriers – Eupergit C and amino glass beads. These preparations were capable of catalyzing the formation of ONPG from β-D-galactose and o-nitrophenol (ONP) under anhydrous conditions. The ability of the catalyst to synthesize the substrate that mediates its own formation creates an autocatalytic cycle where ONPG catalyzes the formation of a catalyst which, in turn, catalyzes ONPG formation. Such autocatalytic cycle can only operate by switching between high and low water activity conditions, such as in tidal pools cycling between wet and dry environments. Implications of the substrate-dependent formation of catalytically active peptides to prebiotic processes are discussed     

The Seven Carbohydrate Bioengineering Meeting,Braunschweig, Germany,April, 22–25, 2007

Stereocontrol in bakers' yeast reduction can be achieved by introduction of a sulfur functional group into substrates. α-Methylthio-β-keto esters are reduced to give exclusively (3S)-3-hydroxy esters. α-Substituted β-keto thiol esters and dithioesters afford (2R,3S)-3-hydroxy esters with high diastereo-and enantioselectivity. Ketones possessing 1,3-dithiane, phenylsulfenyl, or phenylsulfonyl groups at the α-position are transformed also into the corresponding (S)-secondary alcohols. Optically pure (S)-(phenylsulfinyl)acetones can be obtained by kinetic resolution of racemic derivatives with the yeast. Diastereo- and enantioselective reduction of 1,2-diketones leading into (1S,2S)-1,2-diol derivatives can be also achieved by introduction of 1,3-dithiane, phenylsulfenyl or phenylsulfonyl groups into the α-position. Reductions of carbon-carbon double bond of sulfur-functionalized prenyl derivatives provide both chiral (R)- and (S)-C₅-building blocks for terpenoid synthesis. The utility of the reduction products as chiral building blocks is demonstrated in the synthesis of biologically active natural products such as pheromones, sugars, antibiotics etc. by functional group transformation and carbon-carbon bond formation reactions with the aid of sulfur functional groups.     

Of What Use Is Sex to Bacteria?

Though bacteria are predominantly asexual, the genetic information in their genomes can be expanded and modified through mechanisms that introduce DNA from outside sources. Bacterial sex differs from that of eukaryotes in that it is unidirectional and does not involve gamete fusion or reproduction. The input of DNA during bacterial sex generates diversity in two ways--through the alteration of existing genes by recombination and through the introduction of novel sequences--and each of these processes has been shown to aid in the survival and diversification of lineages.