Islet neogenesis is stimulated by brief occlusion of the main pancreatic duct

Objective. Current models of islet neogenesis either cause substantial pancreatic damage or continuously stimulate the pancreas, making these models unsuitable for the study of early events that occur in the neogenic process. We aimed to develop a method where the initial events that culminate in increased pancreatic endocrine mass caube studied. Design and methods. Ten 12-week-old female Wistar rats were subjected to a midline laparotomy, the pancreas was isolated and the main pancreatic duct was occluded for 60 seconds. The pancreas was released and carefully relocated within the abdomen. Ten age-, strain- and sex-matched control rats were subjected to a sham operation. The animals were killed 56 days post .occlusion, and the pancreata excised and fiXed tor histological analysis. Body, pancreatic and hepatic weights were .noted at termination. and serum was taken for analysis. The endocrine-to-exocrine. ratio was calculated and the number of endocrine cells in eacn islet from the sectioned pancreata was counted. Results. Occlusion of the main pancreatic ductfor 60 seconds results in an increase in endocrine mass. by 80% 56 days post occlusion. This constitutes an increase in endocrine units (1 - 6 cellst and in small (7 - 30 cells), medium (31 - 60 cells) and large (> 60 cells) islets by 85%, 96%, 95% and 71% respectively. Conclusion. Brief occlusion of the main pancreatic duct results in anincrease in pancreatic endocrine. mass. An increase in endocrine units and small islets is indicative of islet neogenesis. Therefore, owing to the briefness of the stimulation; this model can therefore be used to study the iniUal events that occur during the neogenic process

Cardioacceleration in alloparents in response to stimuli from prairie vole pups: The significance of thermoregulation

Autonomic responses, including changes in heart rate and respiratory sinus arrhythmia (RSA) can provide indications of emotional reactivity to social stimuli in mammals. We have previously reported that male prairie voles (Microtus ochrogaster) spontaneously care for unfamiliar infants, showing a robust and sustained increase in heart rate in the presence of a pup, thus providing an opportunity to examine the physiology of care-giving in reproductively naïve animals. However, the purpose of such heart rate increases has not been explained by previous efforts. In the present study, we first compared male and female prairie vole cardiac responses in the presence of a pup and found no evidence of sex differences in heart rate or RSA. Using male prairie voles, we then examined the characteristics of pups that were capable of eliciting physiological responses, including age of the pup and pup odors. As prairie vole pups increased in age they vocalized less and there was an associated decline in alloparental cardioacceleration. Exposure to pup-related odors induced cardioacceleration in adult males and this effect also diminished with increasing pup age. Finally, we were able to block the cardioacceleratory effect when the testing environment was warmed to a temperature of 36° C [versus ambient room temperature (approximately 22° C)]. These findings suggest that pup-induced cardioacceleration is a robust phenomenon across alloparental prairie voles of both sexes, and depends on multi-modal processing of different stimuli from the pups. Young pups require care-giving behavior, which appears to drive cardioacceleration in the alloparent. This study also supports the usefulness of autonomic measures in the evaluation of social experiences

Standardised Nomenclature, Abbreviations, and Units for the study of Bone Marrow Adiposity: Report of the Nomenclature Working Group of the International Bone Marrow Adiposity Society

Research into bone marrow adiposity (BMA) has expanded greatly since the late 1990s, leading to development of new methods for the study of bone marrow adipocytes. Simultaneously, research fields interested in BMA have diversified substantially. This increasing interest is revealing fundamental new knowledge of BMA; however, it has also led to a highly variable nomenclature that makes it difficult to interpret and compare results from different studies. A consensus on BMA nomenclature has therefore become indispensable. This article addresses this critical need for standardised terminology and consistent reporting of parameters related to BMA research. The International Bone Marrow Adiposity Society (BMAS) was formed in 2017 to consolidate the growing scientific community interested in BMA. To address the BMA nomenclature challenge, BMAS members from diverse fields established a working group (WG). Based on their broad expertise, the WG first reviewed the existing, unsystematic nomenclature and identified terms, and concepts requiring further discussion. They thereby identified and defined 8 broad concepts and methods central to BMA research. Notably, these had been described using 519 unique combinations of term, abbreviation and unit, many of which were overlapping or redundant. On this foundation a second consensus was reached, with each term classified as “to use” or “not to use.” As a result, the WG reached a consensus to craft recommendations for 26 terms related to concepts and methods in BMA research. This was approved by the Scientific Board and Executive Board of BMAS and is the basis for the present recommendations for a formal BMA nomenclature. As an example, several terms or abbreviations have been used to represent “bone marrow adipocytes,” including BMAds, BM-As, and BMAs. The WG decided that BMA should refer to “bone marrow adiposity”; that BM-A is too similar to BMA; and noted that “Ad” has previously been recommended to refer to adipocytes. Thus, it was recommended to use BMAds to represent bone marrow adipocytes. In conclusion, the standard nomenclature proposed in this article should be Standardised Nomenclature, Abbreviations, and Units for the Study of Bone Marrow Adiposity: Report of the Nomenclature Working Group of the International Bone Marrow Adiposity Society Nathalie Bravenboer, Miriam A. Bredella, [...], and William P. Cawthorn Additional article information Associated Data Supplementary Materials Abstract Research into bone marrow adiposity (BMA) has expanded greatly since the late 1990s, leading to development of new methods for the study of bone marrow adipocytes. Simultaneously, research fields interested in BMA have diversified substantially. This increasing interest is revealing fundamental new knowledge of BMA; however, it has also led to a highly variable nomenclature that makes it difficult to interpret and compare results from different studies. A consensus on BMA nomenclature has therefore become indispensable. This article addresses this critical need for standardised terminology and consistent reporting of parameters related to BMA research. The International Bone Marrow Adiposity Society (BMAS) was formed in 2017 to consolidate the growing scientific community interested in BMA. To address the BMA nomenclature challenge, BMAS members from diverse fields established a working group (WG). Based on their broad expertise, the WG first reviewed the existing, unsystematic nomenclature and identified terms, and concepts requiring further discussion. They thereby identified and defined 8 broad concepts and methods central to BMA research. Notably, these had been described using 519 unique combinations of term, abbreviation and unit, many of which were overlapping or redundant. On this foundation a second consensus was reached, with each term classified as “to use” or “not to use.” As a result, the WG reached a consensus to craft recommendations for 26 terms related to concepts and methods in BMA research. This was approved by the Scientific Board and Executive Board of BMAS and is the basis for the present recommendations for a formal BMA nomenclature. As an example, several terms or abbreviations have been used to represent “bone marrow adipocytes,” including BMAds, BM-As, and BMAs. The WG decided that BMA should refer to “bone marrow adiposity”; that BM-A is too similar to BMA; and noted that “Ad” has previously been recommended to refer to adipocytes. Thus, it was recommended to use BMAds to represent bone marrow adipocytes. In conclusion, the standard nomenclature proposed in this article should be followed for all communications of results related to BMA. This will allow for better interactions both inside and outside of this emerging scientific community

Importance of B4 medium in determining organomineralization potential of bacterial environmental isolates

B4 precipitation medium has been used as the preferred medium for studying mineral precipitation using bacterial strains in vitro since pioneer studies were performed by Boquet and coworkers in 1973. Using this medium, several authors have demonstrated that some environmental isolates were able to precipitate minerals, yet others did not. The main goal of the current study is to understand whether pH and buffer conditions would have a significant effect on mineral precipitation results for environmental isolates grown on B4. For this study, a total of 49 strains isolated from natural environments from Puerto Rico were grown on B4 plates, and their CaCO3 precipitation potential was investigated. Our findings revealed a strong correlation between a lack of CaCO3 precipitation and the acidification of the B4 plates by the colonies. The ability to precipitate CaCO3 could be restored by buffering the B4 medium to a pH of 8.2. Buffering capacity of the medium was proposed to be involved in CaCO3 precipitation: acid-base titrations conducted on the individual ingredients of B4 showed that yeast extract has a poor buffering capacity between pH 6.5?7.5. This pH range corresponds to the pH of B4 plates 6.87 (�±0.05)] prior to the inoculation. This might explain why B4 is such a good precipitation medium: a small variation in the H+/OH? balance during microbial growth and precipitation produces rapid changes in the pH of the medium. Finally, an amorphous matrix was distributed within 90% of the examined crystals generated on B4 medium by the environmental strains. Supplemental materials are available for this article. Go to the publisher's online edition of Geomicrobiology Journal to view the free supplemental file.; B4 precipitation medium has been used as the preferred medium for studying mineral precipitation using bacterial strains in vitro since pioneer studies were performed by Boquet and coworkers in 1973. Using this medium, several authors have demonstrated that some environmental isolates were able to precipitate minerals, yet others did not. The main goal of the current study is to understand whether pH and buffer conditions would have a significant effect on mineral precipitation results for environmental isolates grown on B4. For this study, a total of 49 strains isolated from natural environments from Puerto Rico were grown on B4 plates, and their CaCO3 precipitation potential was investigated. Our findings revealed a strong correlation between a lack of CaCO3 precipitation and the acidification of the B4 plates by the colonies. The ability to precipitate CaCO3 could be restored by buffering the B4 medium to a pH of 8.2. Buffering capacity of the medium was proposed to be involved in CaCO3 precipitation: acid-base titrations conducted on the individual ingredients of B4 showed that yeast extract has a poor buffering capacity between pH 6.5?7.5. This pH range corresponds to the pH of B4 plates 6.87 (�±0.05)] prior to the inoculation. This might explain why B4 is such a good precipitation medium: a small variation in the H+/OH? balance during microbial growth and precipitation produces rapid changes in the pH of the medium. Finally, an amorphous matrix was distributed within 90% of the examined crystals generated on B4 medium by the environmental strains. Supplemental materials are available for this article. Go to the publisher's online edition of Geomicrobiology Journal to view the free supplemental file

Prognostic biomarkers in patients with human immunodeficiency virusâ positive disease with head and neck squamous cell carcinoma

BackgroundWe examined the prognostic value of a panel of biomarkers in patients with squamous cell carcinoma of the head and neck (SCCHN) who were human immunodeficiency virus (HIV) positive (HIVâ positive head and neck cancer) and HIV negative (HIVâ negative head and neck cancer).MethodsTissue microarrays (TMAs) were constructed using tumors from 41 disease siteâ matched and ageâ matched HIVâ positive head and neck cancer cases and 44 HIVâ negative head and neck cancer controls. Expression of tumor biomarkers was assessed by immunohistochemistry (IHC) and correlations examined with clinical variables.ResultsExpression levels of the studied oncogenic and inflammatory tumor biomarkers were not differentially regulated by HIV status. Among patients with HIVâ positive head and neck cancer, laryngeal disease site (P = .003) and Clavienâ Dindo classification IV (CD4) counts <200 cells/μL (P = .01) were associated with poor prognosis. Multivariate analysis showed that p16 positivity was associated with improved overall survival (OS; P < .001) whereas increased expression of transforming growth factorâ beta (TGFâ β) was associated with poor clinical outcome (P = .001).ConclusionDisease site has significant effect on the expression of biomarkers. Expression of tumor TGFâ β could be a valuable addition to the conventional risk stratification equation for improving head and neck cancer disease management strategies.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139994/1/hed24911.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139994/2/hed24911_am.pd

The \u3cem\u3eChlamydomonas\u3c/em\u3e Genome Reveals the Evolution of Key Animal and Plant Functions

Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the ∼120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella

Distinct Functional Roles of β-Tubulin Isotypes in Microtubule Arrays of Tetrahymena thermophila, a Model Single-Celled Organism

<div><h3>Background</h3><p>The multi-tubulin hypothesis proposes that each tubulin isotype performs a unique role, or subset of roles, in the universe of microtubule function(s). To test this hypothesis, we are investigating the functions of the recently discovered, noncanonical β-like tubulins (BLTs) of the ciliate, <em>Tetrahymena thermophila</em>. <em>Tetrahymena</em> forms 17 distinct microtubular structures whose assembly had been thought to be based on single α- and β-isotypes. However, completion of the macronuclear genome sequence of <em>Tetrahymena</em> demonstrated that this ciliate possessed a β-tubulin multigene family: two synonymous genes (<em>BTU1</em> and <em>BTU2</em>) encode the canonical β-tubulin, BTU2, and six genes (<em>BLT1-6</em>) yield five divergent β-tubulin isotypes. In this report, we examine the structural features and functions of two of the BLTs (BLT1 and BLT4) and compare them to those of BTU2.</p> <h3>Methodology/Principal Findings</h3><p>With respect to BTU2, BLT1 and BLT4 had multiple sequence substitutions in their GTP-binding sites, in their interaction surfaces, and in their microtubule-targeting motifs, which together suggest that they have specialized functions. To assess the roles of these tubulins <em>in vivo</em>, we transformed <em>Tetrahymena</em> with expression vectors that direct the synthesis of GFP-tagged versions of the isotypes. We show that GFP-BLT1 and GFP-BLT4 were not detectable in somatic cilia and basal bodies, whereas GFP-BTU2 strongly labeled these structures. During cell division, GFP-BLT1 and GFP-BLT4, but not GFP-BTU2, were incorporated into the microtubule arrays of the macronucleus and into the mitotic apparatus of the micronucleus. GFP-BLT1 also participated in formation of the microtubules of the meiotic apparatus of the micronucleus during conjugation. Partitioning of the isotypes between nuclear and ciliary microtubules was confirmed biochemically.</p> <h3>Conclusion/Significance</h3><p>We conclude that <em>Tetrahymena</em> uses a family of distinct β-tubulin isotypes to construct subsets of functionally different microtubules, a result that provides strong support for the multi-tubulin hypothesis.</p> </div