Characterization of aPY-like peptides in anglerfish brain using a novel radioimmunoassay for aPY-Gly

Anglerfish peptide YG (aPY) was isolated from pancreatic islets of the anglerfish. Subsequent immunohistochemical and biochemical analyses demonstrated that anglerfish islet cells synthesize aPY. We have now developed and characterized a radioimmunoassay (RIA) for aPY and have examined extracts of anglerfish brain for aPY-like peptides. Brain extracts were subjected to gel filtration and high performance liquid chromatography (HPLC). Fractions from HPLC eluates were analyzed in the aPY RIA and also in a neuropeptide Y (NPY) RIA. A single peak of aPY-like immunoreactivity eluted from HPLC columns. The elution position of this aPY-like peptide coincided exactly with the aPY-Gly marker under several gradient conditions. Results from the NPY RIA confirmed the presence of several molecular forms of NPY-like immunoreactive peptides in the anglerfish brain. These results demonstrate the utility of the newly developed aPY RIA for studies of anglerfish brain peptides and extend our previous immunohistochemical demonstration of aPY-like staining in the anglerfish brain.     

Issues in using whole slide imaging for diagnostic pathology: “routine” stains,immunohistochemistry and predictive markers

The traditional microscope, together with the “routine” hematoxylin and eosin (H & E) stain, remains the “gold standard” for diagnosis of cancer and other diseases; remarkably, it and the majority of associated biological stains are more than 150 years old. Immunohistochemistry has added to the repertoire of “stains” available. Because of the need for specific identification and even measurement of “biomarkers,” immunohistochemistry has increased the demand for consistency of performance and interpretation of staining results. Rapid advances in the capabilities of digital imaging hardware and software now offer a realistic route to improved reproducibility, accuracy and quantification by utilizing whole slide digital images for diagnosis, education and research. There also are potential efficiencies in work flow and the promise of powerful new analytical methods; however, there also are challenges with respect to validation of the quality and fidelity of digital images, including the standard H & E stain, so that diagnostic performance by pathologists is not compromised when they rely on whole slide images instead of traditional stained tissues on glass slides.     

Separate cell types that express two different forms of somatostatin in anglerfish islets can be immunohistochemically differentiated

The somatostatin-related peptides somatostatin-14 (SS-14) and somatostatin-28 (aSS-28) are synthesized at the C-terminal end of two separate pre-pro-somatostatins in anglerfish pancreatic islets. The purpose of this study was to determine whether these peptides are expressed in the same or different cell types. Antisera R141 and R293, which recognize the central region of SS-14 and the C-terminal region of aSS-28 ([Tyr7,Gly10] SS-14), respectively, were used in an immunohistochemical examination of anglerfish islets. The R293 antiserum-labeled cells were distributed individually or in small clusters. These same cells, as well as a separate set of cells arranged in large clusters, were stained by the R141 antiserum. Pre-absorption of the R141 antiserum with [Tyr7,Gly10] SS-14 eliminated staining by R141 of only those cells also labeled by R293, whereas pre-absorption of R141 with SS-14 prevented all staining. Pre-absorption of R293 with [Tyr7,Gly10] SS-14 eliminated all staining, whereas pre-absorption with SS-14 had no effect on aSS-28-like immunoreactivity. These results suggest the existence of two separate cell types which express either SS-14 or aSS-28. The cells that contained the somatostatin-related peptides were found to be distinct from those cells that contained insulin, glucagon, or anglerfish peptide Y. However, the cells stained by the R293 antiserum were distributed in close association with glucagon-containing cells. The implications of the existence of separate cell types which express SS-14 or aSS-28 are discussed with regard to processing of the biosynthetic precursors to these peptides.     

Low-dose Ad26.COV2.S protection against SARS-CoV-2 challenge in rhesus macaques

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Solar‐induced chlorophyll fluorescence is strongly correlated with terrestrial photosynthesis for a wide variety of biomes: First global analysis based on OCO‐2 and flux tower observations

Solar‐induced chlorophyll fluorescence (SIF) has been increasingly used as a proxy for terrestrial gross primary productivity (GPP). Previous work mainly evaluated the relationship between satellite‐observed SIF and gridded GPP products both based on coarse spatial resolutions. Finer resolution SIF (1.3 km × 2.25 km) measured from the Orbiting Carbon Observatory‐2 (OCO‐2) provides the first opportunity to examine the SIF–GPP relationship at the ecosystem scale using flux tower GPP data. However, it remains unclear how strong the relationship is for each biome and whether a robust, universal relationship exists across a variety of biomes. Here we conducted the first global analysis of the relationship between OCO‐2 SIF and tower GPP for a total of 64 flux sites across the globe encompassing eight major biomes. OCO‐2 SIF showed strong correlations with tower GPP at both midday and daily timescales, with the strongest relationship observed for daily SIF at the 757 nm (R² = 0.72, p < 0.0001). Strong linear relationships between SIF and GPP were consistently found for all biomes (R² = 0.57–0.79, p < 0.0001) except evergreen broadleaf forests (R² = 0.16, p < 0.05) at the daily timescale. A higher slope was found for C₄ grasslands and croplands than for C₃ ecosystems. The generally consistent slope of the relationship among biomes suggests a nearly universal rather than biome‐specific SIF–GPP relationship, and this finding is an important distinction and simplification compared to previous results. SIF was mainly driven by absorbed photosynthetically active radiation and was also influenced by environmental stresses (temperature and water stresses) that determine photosynthetic light use efficiency. OCO‐2 SIF generally had a better performance for predicting GPP than satellite‐derived vegetation indices and a light use efficiency model. The universal SIF–GPP relationship can potentially lead to more accurate GPP estimates regionally or globally. Our findings revealed the remarkable ability of finer resolution SIF observations from OCO‐2 and other new or future missions (e.g., TROPOMI, FLEX) for estimating terrestrial photosynthesis across a wide variety of biomes and identified their potential and limitations for ecosystem functioning and carbon cycle studies.     

Platelet-derived growth factor BB mediated regulation of 12-lipoxygenase in porcine aortic smooth muscle cells

Platelet-derived growth factor BB (PDGF) is a potent mitogen and chemoattractant for vascular smooth muscle cells (VSMC). In the present study, we have examined the effects of PDGF on the 12-lipoxygenase (12-LO) pathway of arachidonate metabolism in porcine aortic VSMC (PVSMC). The rationale for this is previous studies showing that LO products have growth and chemotactic effects in VSMC and that another VSMC growth factor, angiotensin II, is a potent positive regulator of 12-LO activity and expression. We observed that PDGF causes a significant increase in the formation of the 12-LO product, 12-hydroxyeicosatetraenoic acid (12-HETE) in PVSMC. In addition, PDGF also markedly increased leukocyte-type 12-LO messenger RNA and protein expression. PDGF-induced PVSMC migration was inhibited significantly by two LO blockers but not by a cyclooxygenase blocker. Furthermore, although the proliferative effects of PDGF on PVSMC were not altered by cell culture under hyperglycemic conditions (25 mM glucose, HG), the chemotactic effects of PDGF as well as those of 10% fetal calf serum were significantly greater in cells cultured in HG as compared to normal glucose conditions (5.5 mM), thus indicating a potential new mechanism for the accelerated cardiovascular disease usually observed in diabetes. These results indicate a novel mechanism for the biological effects of PDGF in leading to cardiovascular disease. © 1996 Wiley-Liss, Inc.     

Heatable carbon nanotube composite membranes for sustainable recovery from biofouling

Membrane filtration is one of the most reliable methods for water treatment. However, wider application is limited due to biofouling caused by accumulation of microorganisms on the membrane surface. This report details a heatable carbon nanotube composite membrane with self-cleaning properties for sustainable recovery from biofouling. Microfiltration polycarbonate/carbon-nanotubes hybrid membranes were fabricated using drawable nanotubes that maintained the porosity and provided electrical conductivity to the membrane. Less than 25 V potential and 2–3 W power increase membrane temperature to 100°C in ~10 s. This temperature is above what most microbial life, bacteria and viruses can handle. When this membrane was employed, filtered Escherichia coli collected on its surface were successfully annihilated within 1 min. Ohmic heating of this membrane could be an effective solution to combat biofouling and complications associated with membrane-based filtration. This is a novel and highly desirable approach to combat biofouling, due to its simplicity and economic advantage.     

Increasing chiral recognition in acetal formation

The design of substituted lactols is described, which in their reaction with racemic alkyl aryl carbinols react preferentially with one of the enantiomers exhibiting selectivities up to 14:1.