L364718, a new CCK antagonist, inhibits biological actions of CCK in conscious dogs

The effects of L364718, a new CCK receptor antagonist, on CCK-8 stimulated pancreatic secretion and PP release were examined in three conscious dogs with pancreatic fistulas. L364718 (20 nmol/kg) caused a potent inhibition of CCK-8 stimulated pancreatic protein, amylase and trypsin secretion but not of volume and bicarbonate secretion. Release of PP by CCK was also significantly suppressed by L364718. The degree of inhibition by L364718 was dependent upon the amount of CCK-8 infused. This study demonstrates that L364718 acts as a potent antagonist of CCK's action on pancreatic enzyme secretion and PP release in dogs and suggests that this agent might be a useful tool for studying the physiological role of CCK in conscious animals.     

Large Timescale Interrogation of Neuronal Function by Fiberless Optogenetics Using Lanthanide Micro-particles

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Isolation of a Pandemic O3:K6 Clone of a Vibrio parahaemolyticus Strain from Environmental and Clinical Sources in Thailand

Application of an immunomagnetic enrichment method selective for Vibrio parahaemolyticus serovar K6 allowed isolation of a strain belonging to the pandemic O3:K6 clone of V. parahaemolyticus from fresh shellfish not implicated in a clinical case in southern Thailand. Arbitrarily primed PCR profiles of this strain, clinical O3:K6 strains isolated from sporadic diarrhea cases in the same area, and a standard pandemic O3:K6 strain were indistinguishable.     

Isolation of a <Emphasis Type="Italic">Pseudomonas</Emphasis><Emphasis Type="Italic">aeruginosa</Emphasis> strain from soil that can degrade polyurethane diol

Polyurethane diol (PUR-diol), a synthetic polymer, is widely used as a modifier for water-soluble resins and emulsions in wood appliances and auto coatings. Non-biodegradability of polyurethanes (PUR) and PUR-based materials poses a threat to environment that has led scientists to isolate microbes capable of degrading PUR. However, the bio-degradation of PUR-diol has not yet been reported. In this study, we report isolation of a soil bacterium that can survive using PUR-diol as sole carbon source. PUR-diol degradation by the organism was confirmed by thin layer chromatographic analysis of the conditioned medium obtained after the growth wherein a significant reduction of PUR-diol was observed compared to non-inoculated medium. To quantify the PUR-diol degradation, a sensitive assay based on High Performance Thin Layer Chromatography has been developed that showed 32% degradation of PUR-diol by the organism in 10 days. Degradation kinetics showed the maximal depletion of PUR-diol during logarithmic growth of the organism indicating a direct relation between the growth and PUR-diol degradation. Mutagenic study and GC-MS analysis revealed that esterase activity is involved in this degradation event. The ribotyping and metabolic fingerprinting analysis showed that this organism is a strain of Pseudomonous aeruginosa (P. aeruginosa). It has also been observed that this strain is able to degrade Impranil DLN™, a variety of commercially available PUR. Therefore this study identifies a new bacterium from soil that has the potential to reduce PUR-related waste burden and adds a new facet to diverse functional activities of P. aeruginosa.     

Computational and comparative investigation of hydrophobic profile of spike protein of SARS-CoV-2 and SARS-CoV

The hydrophobic force is one of the most dominant factors in protein folding. A protein becomes functional only when it achieves its three-dimensional structure and stability upon folding. For a better understanding of the hydrophobic effects and their function in protein folding, quantitative measurement of the hydrophobicity of amino acid side chains is crucial. Spike protein is the primary structural protein in SARS-CoV-2 and SARS-CoV. This study explores how protein sequences in SARS-CoV-2 and SARS-CoV spike proteins encode hydrophobic interactions. Computational tools/techniques have been utilized to investigate the protein sequences of the spike proteins of SARS-CoV-2 and SARS-CoV. Investigations provided an estimate of hydrophobic distribution and its relative strength, indicating a hydrophobic pattern. Analysis of the spike protein''s hydrophobic profile may help identify and treat the virus-caused disease; additionally, it can give an insight into the transmissibility and pathogenicity of the virus.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10867-022-09615-x.     

Simultaneous evaluation of substrate-dependent oxygen consumption rates and mitochondrial membrane potential by TMRM and safranin in cortical mitochondria

Mitochondrial membrane potential (mtMP) is critical for maintaining the physiological function of the respiratory chain to generate ATP. The present study characterized the inter-relationship between mtMP, using safranin and tetramethyl rhodamine methyl ester (TMRM), and mitochondrial respiratory activity and established a protocol for functional analysis of mitochondrial bioenergetics in a multi-sensor system. Coupled respiration was decreased by 27 and 30–35% in the presence of TMRM and safranin respectively. Maximal respiration was higher than coupled with Complex I- and II-linked substrates in the presence of both dyes. Safranin showed decreased maximal respiration at a higher concentration of carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP) compared with TMRM. FCCP titration revealed that maximal respiration in the presence of glutamate and malate was not sustainable at higher FCCP concentrations as compared with pyruvate and malate. Oxygen consumption rate (OCR) and mtMP in response to mitochondrial substrates were higher in isolated mitochondria compared with tissue homogenates. Safranin exhibited higher sensitivity to changes in mtMP than TMRM. This multi-sensor system measured mitochondrial parameters in the brain of transgenic mice that model Alzheimer''s disease (AD), because mitochondrial dysfunction is believed to be a primary event in the pathogenesis of AD. The coupled and maximal respiration of electron transport chain were decreased in the cortex of AD mice along with the mtMP compared with age-matched controls. Overall, these data demonstrate that safranin and TMRM are suitable for the simultaneous evaluation of mtMP and respiratory chain activity using isolated mitochondria and tissue homogenate. However, certain care should be taken concerning the selection of appropriate substrates and dyes for specific experimental circumstances.     

A method for screening rice plants for salt tolerance

A number of varieties of rice, a halophyte, Sesuvium portulacastrum and a glycophyte, Phaseolus vulgaris were grown in culture solution containing a range of concentrations of NaCl. Growth of the plants and internal sodium concentrations of the roots were measured after 14 days. The electrical potential difference (PD) between the external solution and the vacuole of the outer cells of the root was also measured. This enabled the driving force on sodium at the cell membranes to be calculated using the Nernst equation. It was found that Sesuvium and those varieties of rice that had previously shown salt tolerance generated relatively negative PDs and large driving forces tending to exclude sodium from the root. This suggested that a simple measurement of PD for plants grown in a given concentration of NaCl over a given period of time would provide a fairly rapid screening method for salt tolerance in rice and possibly other species also. T J Flowers Section editor