Structural basis for the recognition of α-1,6-branched α-glucan by GH13_47 α-amylase from Rhodothermus marinus.

Glycoside hydrolase (GH) family 13 is among the main families of enzymes acting on starch; recently, subfamily 47 of GH13 (GH13_47) has been established. The crystal structure and function of a GH13_47 enzyme from Bacteroides ovatus has only been reported to date. This enzyme has α-amylase activity, while the GH13_47 enzymes comprise approximately 800-900 amino acid residues which are almost double those of typical α-amylases. It is important to know how different the GH13_47 enzymes are from other α-amylases. Rhodothermus marinus JCM9785, a thermophilic bacterium, possesses a gene for the GH13_47 enzyme, which is designated here as RmGH13_47A. Its structure has been predicted to be composed of seven domains: N1, N2, N3, A, B, C, and D. We constructed a plasmid encoding Gly266-Glu886, which contains the N3, A, B, and C domains and expressed the protein in Escherichia coli. The enzyme hydrolyzed starch and pullulan by a neopullulanase-type action. Additionally, the enzyme acted on maltotetraose, and saccharides with α-1,6-glucosidic linkages were observed in the products. Following the replacement of the catalytic residue Asp563 with Ala, the crystal structure of the variant D563A in complex with the enzymatic products from maltotetraose was determined; as a result, electron density for an α-1,6-branched pentasaccharide was observed in the catalytic pocket, and Ile762 and Asp763 interacted with the branched chain of the pentasaccharide. These findings suggest that RmGH13_47A is an α-amylase that prefers α-1,6-branched parts of starch to produce oligosaccharides.

Association among childhood adversity and susceptibility to interference during varying salience: two studies in healthy males.

Childhood adversity, a prevalent experience, is related to a higher risk for externalizing and internalizing psychopathology. Alterations in the development of cognitive processes, for example in the attention-interference domain may link childhood adversity and psychopathology. Interfering stimuli can vary in their salience, i.e. ability to capture attentional focus, and valence. However, it is not known if interference by salience or valence is associated with self-reported adversity. In two independent study samples of healthy men (Study 1: n = 44; mean age [standard deviation (SD)] = 25.9 [3.4] years; Study 2: n = 37; 43.5 [9.7] years) we used the attention modulation task (AMT) that probed interference by two attention-modulating conditions, salience and valence separately across repeated target stimuli. The AMT measures the effects of visual distractors (pictures) on the performance of auditory discrimination tasks (target stimuli). We hypothesized that participants reporting higher levels of childhood adversity, measured with the childhood trauma questionnaire, would show sustained interference in trials with lower salience. Due to conflicting reports on the valence-modulation, we tested the valence condition in an exploratory manner. Linear mixed models revealed an interaction between reported childhood adversity and the salience condition across tone presentations in both study samples (Sample 1: p = .03; Sample 2: p = .04), while there were no effects for the valence condition across both studies. Our study suggests that higher self-reported childhood adversity is related to faster processing of target cues during high salience, but slower during low salience conditions. These results hint to the mechanisms linking childhood adversity and psychopathological symptoms in the attentional domain.

Insect α-Amylases and Their Application in Pest Management.

Amylase is an indispensable hydrolase in insect growth and development. Its varied enzymatic parameters cause insects to have strong stress resistance. Amylase gene replication is a very common phenomenon in insects, and different copies of amylase genes enable changes in its location and function. In addition, the classification, structure, and interaction between insect amylase inhibitors and amylases have also invoked the attention of researchers. Some plant-derived amylase inhibitors have inhibitory activities against insect amylases and even mammalian amylases. In recent years, an increasing number of studies have clarified the effects of pesticides on the amylase activity of target and non-target pests, which provides a theoretical basis for exploring safe and efficient pesticides, while the exact lethal mechanisms and safety in field applications remain unclear. Here, we summarize the most recent advances in insect amylase studies, including its sequence and characteristics and the regulation of amylase inhibitors (α-AIs). Importantly, the application of amylases as the nanocide trigger, RNAi, or other kinds of pesticide targets will be discussed. A comprehensive foundation will be provided for applying insect amylases to the development of new-generation insect management tools and improving the specificity, stability, and safety of pesticides.

Natural Inhibitors of Mammalian α-Amylases as Promising Drugs for the Treatment of Metabolic Diseases.

α-Amylase is a generally acknowledged molecular target of a distinct class of antidiabetic drugs named α-glucosidase inhibitors. This class of medications is scarce and rather underutilized, and treatment with current commercial drugs is accompanied by unpleasant adverse effects. However, mammalian α-amylase inhibitors are abundant in nature and form an extensive pool of high-affinity ligands that are available for drug discovery. Individual compounds and natural extracts and preparations are promising therapeutic agents for conditions associated with impaired starch metabolism, e.g., diabetes mellitus, obesity, and other metabolic disorders. This review focuses on the structural diversity and action mechanisms of active natural products with inhibitory activity toward mammalian α-amylases, and emphasizes proteinaceous inhibitors as more effective compounds with significant potential for clinical use.

Macroamylasemia as a Rare Cause of Hyperamylasemia: A Case Report.

Macroamylasemia is a rare condition characterized by the formation of an amylase-globulin complex that is too large to be readily excreted by the kidneys and leads to elevated serum amylase levels. It is a benign condition lacking severe signs and symptoms that does not require treatment. This paper presents a case of a middle-aged man with unexplained elevated serum amylase levels. Despite an initially elevated triglyceride level, clinical findings, laboratory test results, and radiological findings were not suggestive of pancreatitis. The ratio of renal amylase clearance to creatinine clearance was calculated at <1%, consistent with macroamylasemia. No specific treatment was given, and he was monitored periodically. Nevertheless, macroamylasemia is a diagnostic challenge because of the need to differentiate it from other causes of hyperamylasemia to avoid unnecessary tests and treatments.

Adsorption properties of corn starch modified by malt amylases and crosslinking agents: A comparison between sodium trimetaphosphate and organic acids.

In order to investigate the effects of different crosslinking agents on physicochemical properties and adsorption properties of porous starch. Native corn starch was hydrolyzed by maltase and crosslinked with different crosslinking agents. Sodium trimetaphosphate crosslinked porous starch (STMP-MPS), malic acid cross-linked porous starch (MA-MPS) and citric acid cross-linked porous starch (CA-MPS) were prepared. After crosslinking, MA-MPS and CA-MPS showed a new CO stretching absorption peak at 1738 cm-1, and the crosslinking degree was much higher than that of STMP-MPS. The surface area of MA-MPS was 36 % higher than that of STMP-MPS. Compared with the average pore size of 12.43 nm of STMP-MPS, CA-MPS (14.02 nm) and MA-MPS (14.79 nm) were increased more significantly. The degradation temperature of MA-MPS and CA-MPS was increased by the introduction of ester bond, which indicates that the organic acid cross-linking strengthens the starch granules and hence more energy is required for disruption. Compared with STMP-MPS, the water absorption of MA-MPS and CA-MPS increased by 64 % and 32 %, respectively. Furthermore, the adsorption capacity of MA-MPS to essential oil was the strongest, about 4 times that of STMP-MPS. Overall, it is feasible to modify porous starch by crosslinking reaction to improve its heat resistance and adsorption properties.

Clinical correlation of salivary alpha-amylase levels with pain intensity in patients undergoing emergency endodontic treatment.

BACKGROUND: Pain is usually subjective and thus it is challenging to describe its characteristics such as nature, intensity, and origin. Non-invasive methods such as assessing salivary alpha-amylase (SAA) may aid the practitioner to evaluate the pain intensity. Hence, the current study aimed to correlate the levels of SAA with the pain intensity in patients presenting with varied endodontic pain levels. METHODS: Sixty patients who presented with varied intensities of endodontic pain were selected for the present study out of which seven patients were excluded/dropped, leaving a total sample of fifty-five patients for assessment. Mandibular molar with symptomatic irreversible pulpitis without periapical pathology were included in the study. A 5ml of un-stimulated was obtained from the patients, following which the local anesthesia was administered. Root canal treatment was then performed and the pain scores at pre-operative and post-operative were recorded. Additionally, salivary samples were collected after emergency endodontic treatment and sent for sialochemical analysis. IBM.SPSS statistics software 23.0 was employed to assess the obtained data. RESULTS: A statistically significant drop in the pain score (P < 0.001) and SAA levels (P < 0.001) were observed post-operatively in the contract to pre-operative state. A strong positive correlation was reported between SAA levels and pain scores in patients undergoing emergency endodontic treatment at both time intervals namely pre-operative (P < 0.001) and post-operative (P < 0.001). CONCLUSION: The results of this preliminary showed a strong association between the pain score and SAA levels in patients undergoing an emergency endodontic treatment.

Is Endoscopy Mandatory In Cases Mimicking Acute Pancreatitis?

Objectives: To detect the utility of nonspecific rising of pancreatic enzymes in patients with stomach discomfort, and to explore the possibility of hyperamylasemia as a differential diagnosis. Method: The cross-sectional study was conducted from April 2020 to April 2021 at two large tertiary care centres in Kafrelsheikh and Zagazig governorates in northern Egypt, and comprised patients complaining of dull aching abdominal pain. They were classified into two groups. Patients with nonspecific rise in pancreatic enzymes less than threefold in the absence of acute pancreatitis were in group I, while those having abdominal pain without rise in pancreatic enzymes were in group II. All patients were subjected to detailed history and clinical examination followed by laboratory assessment, imaging studies and upper endoscopy. Data was analysed using SPSS 20. RESULTS: Of the 270 patients, 170(63%) were in group I; 120(70.5%) males and 50(29.5%) females with mean age 51±6.58 years, There were 100(37%) patientsin group II; 65(65%) males and 35(35%) females with mean age 53±8.96 years (p>0.05). Amylase, lipase, serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase, Creactive protein and helicobacter pylori values were significantly different between the groups (p<0.05). CONCLUSIONS: Elevation of pancreatic enzymes with a level less than three-fold in patients with abdominal pain reflected mucosal injury of the gastrointestinal tract and may raise the necessity for diagnostic upper endoscopy.

Seed priming mitigates high salinity impact on germination of bread wheat (Triticum aestivum L.) by improving carbohydrate and protein mobilization.

Salinity is increasingly considered as a major environmental issue, which threatens agricultural production by decreasing yield traits of crops. Seed priming is a useful and cost-effective technique to alleviate the negative effects of salinity and to enable a fast and uniform germination. In this context, we quantified the effects of priming with gibberellic acid (GP), calcium chloride (CP), and mannitol (MP) on seed germination of three bread wheat cultivars and investigated their response when grown at high salinity conditions (200 mM NaCl). Salt exposure strongly repressed seed imbibition and germination potential and extended germination time, whereas priming enhanced uniformity and seed vigor. Seed preconditioning alleviated the germination disruption caused by salt stress to varying degrees. Priming mitigating effect was agent-dependent with regard to water status (CP and MP), ionic imbalance (CP), and seed reserve mobilization (GP). Na+ accumulation in seedling tissues significantly impaired carbohydrate and protein mobilization by inhibiting amylase and proteases activities but had lesser effects on primed seeds. CP attenuated ionic imbalance by limiting sodium accumulation. Gibberellic acid was the most effective priming treatment for promoting the germination of wheat seeds under salt stress. Moreover, genotypic differences in wheat response to salinity stress were observed between varieties used in this study. Ardito, the oldest variety, seems to tolerate better salinity in priming-free conditions; Aubusson resulted the most salt-sensitive cultivar but showed a high germination recovery under priming conditions; Bologna showed an intermediate behavior.

Effect of propofol on salivary secretion from the submandibular, sublingual, and labial glands during intravenous sedation.

Background: Recent animal studies have suggested the role of GABA type A (GABA-A) receptors in salivation, showing that GABA-A receptor agonists inhibit salivary secretion. This study aimed to evaluate the effects of propofol (a GABA-A agonist) on salivary secretions from the submandibular, sublingual, and labial glands during intravenous sedation in healthy volunteers. Methods: Twenty healthy male volunteers participated in the study. They received a loading dose of propofol 6 mg/kg/h for 10 min, followed by 3 mg/kg/h for 15 min. Salivary flow rates in the submandibular, sublingual, and labial glands were measured before, during, and after propofol infusion, and amylase activity was measured in the saliva from the submandibular and sublingual glands. Results: We found that the salivary flow rates in the submandibular, sublingual, and labial glands significantly decreased during intravenous sedation with propofol (P < 0.01). Similarly, amylase activity in the saliva from the submandibular and sublingual glands was significantly decreased (P < 0.01). Conclusion: It can be concluded that intravenous sedation with propofol decreases salivary secretion in the submandibular, sublingual, and labial glands via the GABA-A receptor. These results may be useful for dental treatment when desalivation is necessary.

Salivary protein biomarkers for diagnosis of oral squamous cell carcinoma.

OSCC (Oral Squamous Cell Carcinoma) is a major health challenge in many parts of the world. It occurs most commonly in males and is associated with tobacco, pan, or areca nut consumption. One of the major challenges associated with the management of OSCC is late diagnosis. As a result, the treatment required is more aggressive, expensive, and has poor prognostic value. On the other hand, early diagnosis of OSCC can be life-saving with less aggressive treatment and a better prognosis. A diagnostic method for early diagnosis of OSCC is greatly needed. A lot of research efforts have been made to identify biomarkers that can act as tools to classify the tumor status of the patient. Various biological fluids and tissues have been explored for such studies. Saliva appears to be the most attractive biological sample with many potential advantages over other matrices such as blood or tissue. Saliva as a diagnostic fluid has the advantage of ample availability, being non-invasive and being in the vicinity of the tumor, and having a less complex composition. Our paper provides an updated review of the state of the art of research in the area of salivary biomarkers for oral squamous cell carcinoma. The paper gives an account of methods for saliva collection, followed by a brief description of various protein biomarkers discovered to date, along with their status quo.

Microscopic assessment of the degradation of millet starch granules by endogenous and exogenous enzymes during mashing.

The high gelatinization temperature (GT) of millet starch prevents the usage of infusion or step mashes as an effective means to generate fermentable sugars (FS) in brewing because the malt amylases lack thermostability at GT. Here, we investigate processing modifications to determine if millet starch can be efficiently degraded below GT. We determined that producing finer grists through milling did not introduce enough granule damage to markedly change gelatinization characteristics, though there was improved liberation of the endogenous enzymes. Alternatively, exogenous enzyme preparations were added to investigate their ability to degrade intact granules. At the recommended dosages (0.625 µL/g malt), significant FS concentrations were observed, although at lower concentrations and with a much-altered profile than possible with a typical wort. When exogenous enzymes were introduced at high (10×) addition rates, significant losses of granule birefringence and granule hollowing were observed well below GT, suggesting these exogenous enzymes can be utilized to digest millet malt starch below GT. The exogenous maltogenic α-amylase appears to drive the loss of birefringence, but more research is needed to understand the observed predominate glucose production.

The salivary alpha-amylase concentration in patients with rheumatoid arthritis: A case-control study.

Background: Rheumatoid arthritis (RA) is one of the most common chronic inflammatory diseases. Previous studies have reported an association between stress and salivary alpha-amylase. The aim of this study was to investigate the concentration of salivary alpha-amylase in patients with RA (by elimination of stress factor). Materials and Methods: In this case-control study, we enrolled 50 patients with RA and 48 healthy patients as the control group. The perceived stress scale questionnaire was used to evaluate scores of stress in both case and control groups, and then the participants with high scores of stress were excluded from the study. Moreover, the alpha-amylase activity kit was used for the assessment of the levels of salivary alpha-amylase. In all analyses, the significance level was considered to be < 0.05. Finally, the obtained data were analyzed by SPSS22. Results: Our results indicated a high score of stress in the case group (19.42 ± 5.83 units) compared with the control group (18.02 ± 6.07 units) which was not statistically significant (P < 0.248). Moreover, we demonstrated a high salivary alpha-amylase concentration in the case group (340.65 ± 38.04 units) compared to the control group (302.62 ± 58.72 units), which was statistically significant (P < 0.001). The sensitivity and specificity of this method, at >312 alpha-amylase concentrations, were 80% and 46%, respectively. Conclusion: In general, we indicated that the alpha-amylase concentration in patients with RA is higher than the healthy controls, and can be used as a codiagnostic factor.

Role of vitamin C and rectal indomethacin in preventing and alleviating post-endoscopic retrograde cholangiopancreatography pancreatitis: a clinical study.

BACKGROUND/AIMS: This study aimed to determine whether vitamin C in addition to indomethacin decreases the occurrence and severity of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) occurrence and severity. METHODS: This randomized clinical trial included patients undergoing ERCP. The participants were administered either rectal indomethacin (100 mg) plus an injection of vitamin C (500 mg) or rectal indomethacin (100 mg) alone just before ERCP. The primary outcomes were PEP occurrence and severity. The secondary amylase and lipase levels were determined after 24 hours. RESULTS: A total of 344 patients completed the study. Based on intention-to-treat analysis, the PEP rates were 9.9% for indomethacin plus vitamin C plus indomethacin and 15.7% for indomethacin alone. Regarding the per-protocol analysis, the PEP rates were 9.7% and 15.7% in the combination and indomethacin arms, respectively. There was a remarkable difference between the two arms in PEP occurrence and severity on intention-to-treat and per-protocol analyses (p=0.034 and p=0.031, respectively). The post-ERCP lipase and amylase concentrations were lower in the combination arm than in the indomethacin alone arm (p=0.034 and p=0.029, respectively). CONCLUSION: Vitamin C injection in addition to rectal indomethacin reduced PEP occurrence and severity.

Maltooligosaccharides: Properties, Production and Applications.

Maltooligosaccharides (MOS) are homooligosaccharides that consist of 3-10 glucose molecules linked by α-1,4 glycosidic bonds. As they have physiological functions, they are commonly used as ingredients in nutritional products and functional foods. Many researchers have investigated the potential applications of MOS and their derivatives in the pharmaceutical industry. In this review, we summarized the properties and methods of fabricating MOS and their derivatives, including sulfated and non-sulfated alkylMOS. For preparing MOS, different enzymatic strategies have been proposed by various researchers, using α-amylases, maltooligosaccharide-forming amylases, or glycosyltransferases as effective biocatalysts. Many researchers have focused on using immobilized biocatalysts and downstream processes for MOS production. This review also provides an overview of the current challenges and future trends of MOS production.

Resistant starch utilization by Bifidobacterium, the beneficial human gut bacteria.

Resistant starch (RS) reaches the large intestine largely intact, where it is fermented by the gut microbiota, resulting in the production of short-chain fatty acids (SCFAs) that have beneficial effects on the human body. Bifidobacteria are a major species widely used in the probiotic field, and are increased in the gut by RS, indicating their importance in RS metabolism in the intestine. Bifidobacteria have a genetic advantage in starch metabolism as they possess a significant number of starch-degrading enzymes and extraordinary three RS-degrading enzymes, allowing them to utilize RS. However, to date, only three species of RS-degrading bifidobacteria have been reported as single isolates B. adolescentis, B. choerinum, and B. pseudolongum. In this review, we describe recent studies on RS utilization by Bifidobacterium, based on their biochemical characteristics and genetic findings. This review provides a crucial understanding of how bifidobacteria survive in specific niches with abundant RS such as the human gut.

Impact of mashing protocol on the formation of fermentable sugars from millet in gluten-free brewing.

The production of fermentable sugars (FS) in gluten-free (GF) brewing is hindered by the high starch gelatinization temperatures of GF malts and lower diastatic power compared to barley malt. Our previous work has demonstrated that starch gelatinization was the primary hurdle, and when decoupled from a single mash phase, high concentrations of FS could be produced. However, more research was required to improve the applicability of GF brewing. In this study, millet was used as a model GF malt demonstrating that despite the low α-amylase and ß-amylase activities compared to barley malt âˆ¼ 90 % of the FS (∼110 g/L) could be produced within 40 min. Limitations to enzyme extraction and separation due to coarse milling and lautering initially limited FS by âˆ¼ 30 g/L, requiring additional processing or exogenous enzyme supplements that improved fermentable sugar generation by âˆ¼ 20 g/L. Overall, millet is a promising brewing ingredient, provided appropriate mashing procedures are implemented.

Type 1 Diabetes: A Disorder of the Exocrine and Endocrine Pancreas.

Type 1 diabetes has historically been described as an endocrine (ß-cell) specific autoimmune disease. However, a substantial reduction (20-50%) in pancreas organ size and subclinical to symptomatic exocrine pancreatic insufficiency are present at diagnosis and may begin even prior to the development of islet autoimmunity. The mechanisms of exocrine loss in type 1 diabetes are not well understood, but leading hypotheses include developmental defects, ß-cell loss resulting in exocrine atrophy, or autoimmune or inflammatory destruction of exocrine cells. Inflammatory changes including acute and chronic pancreatitis, exocrine T cell infiltration and classical complement activation, and serum exocrine autoantibodies within type 1 diabetes individuals suggest that an autoimmune or inflammatory process may contribute to exocrine pancreatic dysfunction. Exocrine pancreas atrophy primarily occurs prior to the onset of clinical disease. Indeed, recent work implicates exocrine-specific alterations in gene and protein expression as key in type 1 diabetes development. Measures of exocrine size and function could be useful additions in the prediction of disease onset and in identifying potential therapeutic responders to disease therapies, however, this is an underdeveloped area of research. Additionally, exocrine pancreatic insufficiency is underdiagnosed in individuals with type 1 diabetes and individualized treatment protocols are lacking. Much work remains to be done in this area, but we can definitively say that type 1 diabetes is a disorder of both the exocrine and endocrine pancreas likely from the start.

Historical evolution of pancreatic fistula definition and current grading limitations and potential improvements / 国际外科学杂志

Pancreatic fistula is one of the most important complications after pancreatic surgery. The International Study Group on Pancreatic Fistula proposed the definition and classification of postoperative pancreatic fistula (POPF) in 2005 firstly, which has promoted the development of pancreatic surgery research. And the International Study Group on Pancreatic Surgery modified the POPF standard in 2016 and paid more attention to clinical relevance. The POPF is often used to evaluate anastomotic methods. However, this grading version is based on clinical outcomes, which more represents the comprehensive treatment effect than reflects the quality of pancreaticojejunostomy. Using the current POPF grading criteria for the purpose of improving anastomosis methods is not very accurate, so an indicator that only reflects anastomosis′ quality is needed for the comparison of various surgical methods. To avoid the influence of non-reconstruction elements on the incidence and degree of POPF, this research team prefer the total drainage fluid amylase(DFA)or the duration of high DFA. And in this way, the comparation among different anastomotic operations could be specific and objective, which further helps to find out an ideal method for pancreatic digestive tract reconstruction.

Spectrophotometric Analysis and Determination of Anti-inflammatory Effect of Punica granatum and Woodfordia fruticosa in Subjects With Chronic Periodontitis - A Randomized Controlled Clinical Trial.

INTRODUCTION: Long-term use of chemical plaque control methods has led to adverse effects. In the current scenario, herbal mouthwashes have adequately remediated periodontal disease. Moreover, in the salivary interactome, biomarkers such as salivary amylase, a key protein secreted in the saliva, have been immensely useful in detecting the progression of periodontal disease. Therefore, we aimed to determine the anti-inflammatory effect of ethanolic crude extracts of Woodordiafruticosa leaf and Punicagranatum peel and to estimate salivary amylase levels in subjects diagnosed with chronic periodontitis. METHODOLOGY: Ethanolic extracts of both plants were prepared using the soxhlet extraction method, and the obtained metabolites were confirmed by thin-layer chromatography. After a mouthwash was prepared, 100 subjects were randomly divided into two groups. Group I received Punica peel (Pgp) mouthwash, and Group II received Woodfordialeaf (Wfl). Clinical parameters such as probing depth and clinical attachment loss were recorded to determine the grades of periodontitis. Unstimulated whole saliva was collected, and amylase levels were analyzed at three-time intervals using spectrophotometric assay. RESULTS: For both groups, the mean reduction in salivary amylase levels was calculated at baseline after 1 hour and 1 week of using the mouthwash. A statistically highly significant reduction was seen with (p=0.000*) at the 1-hr interval in Group I. CONCLUSION: The anti-inflammatory effect was more effective with Pgp mouthwash when compared to Wfl mouthwash.