Mixed-type Pattern Research Articles

Inhibitory mechanism of apigenin, quercetin, and phloretin on α-glucosidase

Flavonoids present promising potential as α-glucosidase inhibitors, with potential benefits in lowering blood glucose levels. In our previous study, apigenin, quercetin, and phloretin obtained from whole-grain highland barley demonstrated notable efficacy as α-glucosidase inhibitors. Therefore, in this study, we used enzyme kinetics, fluorescence spectroscopy, circular dichroism, and molecular docking to explore the interactions between apigenin, quercetin, and phloretin, and α-glucosidase. With the addition of three flavonoids, the inhibitory effect of all the flavonoids on α-glucosidase activity was reversible and exhibited a mixed-type pattern. Molecular docking analysis revealed that the three flavonoids predominantly bind to yeast-derived α-glucosidase mainly through hydrophobic interactions and van der Waals forces, whereas the interaction with human-derived α-glucosidase involved hydrophobic interactions. Further experiments revealed that the flavonoids quenched the fluorescence of α-glucosidase due to the complex formation between the flavonoids and α-glucosidase, leading to changes in the protein secondary structure and conformational changes, which was further supported by molecular dynamics simulations. These results provided insights into the mechanism of the flavonoid inhibition of α-glucosidase. These findings could promote the consumption of whole-grain highland barley and the development of hypoglycemic foods rich in flavonoids.

Liver Injury in Patients with COVID-19 without Underlying Liver Disease.

SARS-CoV-2 shows a high affinity for the ACE-2 receptor, present on the epithelial cells of the upper and lower respiratory tract, within the intestine, kidneys, heart, testes, biliary epithelium, and—where it is particularly challenging—on vascular endothelial cells. Liver involvement is a rare manifestation of COVID-19. Material and Methods: We reviewed 450 patients admitted due to the fact of SARS-CoV-2 infection (COVID-19) including 88 with liver injury. Based on medical history and previous laboratory test results, we excluded cases of underlying liver disease. The analysis involved a clinical course of COVID-19 in patients without underlying liver disease as well as the type and course of liver injury. Results: Signs and symptoms of liver injury were present in 20% of patients, mostly presenting as a mixed-type pattern of injury with less common cases of standalone hepatocellular (parenchymal) or cholestatic injury. The liver injury symptoms resolved at the end of inpatient treatment in 20% of cases. Sixteen patients died with no cases where liver injury would be deemed a cause of death. Conclusions: (1) Liver injury secondary to COVID-19 was mild, and in in 20%, the signs and symptoms of liver injury resolved by the end of hospitalization. (2) It seems that liver injury in patients with COVID-19 was not associated with a higher risk of mortality. (3) The underlying mechanism of liver injury as well as its sequelae are not fully known. Therefore, caution and further monitoring are advised, especially in patients whose liver function tests have not returned to normal values.

High Prevalence of Early Parkinson's Disease in Patients With Subtle Parkinsonian Signs.

Background: Little is known about how frequently patients with a Unified Parkinson Disease Rating Scale part III (UPDRS-III) score of 3 or 4, including postural and action tremor, could be classified into early Parkinson's disease (PD).Objective: To examine the prevalence of early PD in patients with subtle parkinsonian signs (rest tremor, postural tremor, and rigidity) without bradykinesia, having a UPDRS-III score of 3 or 4.Methods: Parkinsonism was assessed using UPDRS-III based on both the United Kingdom PD Society Brain Bank criteria and the Movement Disorder Society PD criteria. Ninety patients with a UPDRS-III score of 3 or 4, including postural tremor, were evaluated by 123I-FP-CIT SPECT (DaTscan), brain MRI, the Mini-Mental State Examination, and smell test. Some patients were additionally examined by 123I-metaiodobenzylguanidine myocardial scintigraphy or 123I-N-isopropyl-p-iodoamphetamine SPECT.Results: Seventy-five [mean age (standard deviation): 76.9 (8.1)] out of 90 patients (83.3%) showed abnormal findings on DaTscan imaging: 57 out of 75 (76.0%) showed a reduced specific binding ratio (SBR) accompanied by an egg shape pattern (n = 37, 49.3%) or a mixed type pattern (n = 14, 18.7%), both reduced SBR and increased asymmetry index (AI) with a normal shape (n = 4, 5.3%), and reduced SBR only (n = 2, 2.7%); 18 (24.0%) showed an egg shape pattern or a mixed type pattern without reduced SBR. In other words, 69 out of 75 patients (92.0%) showed either an egg shape or a mixed type pattern with or without reduced SBR. All patients were free of dementia, and their olfactory function was significantly impaired compared with controls (n = 141) on the odor-stick identification test for Japanese (p < 0.0001).Conclusions: The prevalence of patients with subtle parkinsonian signs having a UPDRS-III score of 3 or 4, including postural tremor, is unexpectedly high in daily clinical practice, and most of these patients could be categorized into mild early-stage PD.

A Graph-Theoretic Approach for Spatial Filtering and Its Impact on Mixed-Type Spatial Pattern Recognition in Wafer Bin Maps

Statistical quality control in semiconductor manufacturing hinges on effective diagnostics of wafer bin maps, wherein a key challenge is to detect how defective chips tend to spatially cluster on a wafer--a problem known as spatial pattern recognition. Recently, there has been a growing interest in mixed-type spatial pattern recognition--when multiple defect patterns, of different shapes, co-exist on the same wafer. Mixed-type spatial pattern recognition entails two central tasks: (1) spatial filtering, to distinguish systematic patterns from random noises; and (2) spatial clustering, to group filtered patterns into distinct defect types. Observing that spatial filtering is instrumental to high-quality mixed-type pattern recognition, we propose to use a graph-theoretic method, called adjacency-clustering, which leverages spatial dependence among adjacent defective chips to effectively filter the raw wafer maps. Tested on real-world data and compared against a state-of the-art approach, our proposed method achieves at least 46% gain in terms of internal cluster validation quality (i.e., validation without external class labels), and about ~5% gain in terms of Normalized Mutual Information--an external cluster validation metric based on external class labels. Interestingly, the margin of improvement appears to be a function of the pattern complexity, with larger gains achieved for more complex-shaped patterns.

Patterns of local extension and nodal involvement from 1300 nasopharyngeal carcinoma patients: An imaging-based predictor of distant metastases.

e17516 Background: Distant metastasis is a main determinant of prognosis in patients with nasopharyngeal carcinoma(NPC). We explored the patterns of disease spread in NPC patients and identified the pattern correlates with distant metastases. Methods: The imaging documents of 1300 consecutive newly diagnosed nasopharyngeal carcinoma between 2012 and 2016 were reviewed. According to the incidence rates of tumor invasion, the anatomic sites were classified into high-risk group (≥50%), medium-risk group (≥10%~ &lt; 50%) and low-risk group ( &lt; 10%). The location of lymph nodes was determined by 2013 updated guidelines for neck node levels. Additionally, we developed a novel classification based on tumor spreading patterns, as shown in Table. Moreover, we validated the prognostic accuracy of the classification in a validation cohort from a different institution, 241 non-metastatic NPC patients were retrospectively enrolled. Kaplan-Meier method and log-rank test were used to analyze all time-to-event data. Results: The incidence rates of tumor invasion were 0.2% ~91.2%, 95.2% cases across the midline. If anatomic sites in high-risk group or median-risk group were involved, the incidence rates in adjacent medium-risk sites or low-risk group were increased. On the contrary, the incidence rates were decreased when the adjacent high-risk sites or median-risk group were not involved. 85.9% cases had involved lymph nodes. Only 3.9% had skip metastases. The incidence rates of nodal involvement were increased when adjacent upper nodal level was involved. In validation cohort, distant metastases were present in 32/241 NPC patients (13.3%) and 3-year distant metastasis-free survival(DMFS) in local, superior, inferior, and mixed type were 95.0%, 91.3%, 89.0%, and 78.7%, respectively. Cumulative survival curves for former three patterns were relatively similar and were clearly separated from mixed type. DMFS was significantly lower for patients with mixed type pattern than for those with other patterns(P = 0.018). Conclusions: Local disease in NPC patients spreads stepwise from proximal sites to more distal sites. The frequency of metastases in the jugular lymph node chains decreased in the cranio-caudal direction. Based on the patterns of tumor extension, an imaging-based predictor of distant metastases was developed and may be used as a prognostic marker for selecting patients to further systemic treatments. [Table: see text]

In vitro antioxidant, anti-diabetic and antilipemic potentials of quercetagetin extracted from marigold (Tagetes erecta L.) inflorescence residues.

Quercetagetin, the major flavonoid in marigold (Tagetes erecta L.) inflorescence residues was extracted and purified. The content of quercetagetin after the purification was 89.91 ± 0.26%. The in vitro antioxidant activity of quercetagetin and its potential in controlling diabetes mellitus and obesity were investigated and compared to quercetin and rutin. The 50% inhibitory concentration (IC50) values of quercetagetin on scavenging 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) and hydroxyl radicals were 27.12 ± 1.31μmol/L, 12.16 ± 0.56μmol/L and 1833.97 ± 6.66μmol/L, respectively. The IC50 values of quercetagetin on α-glucosidase, α-amylase and pancreatic lipase were 180.11 ± 3.68μmol/L, 137.71 ± 3.55μmol/L and 2327.58 ± 12.37μmol/L, respectively. These results indicated that quercetagetin exhibited strong in vitro antioxidant, anti-diabetic and antilipemic activities. Lineweaver-Burk plots analysis elucidated that quercetagetin inhibited α-glucosidase and α-amylase non-competitively, while its inhibition against pancreatic lipase was involved in a mixed-type pattern. Moreover, strong correlations were found between ABTS(·+)/DPPH(·) scavenging activities and lipase inhibitory activity (R (2) > 0.90), as well as ·OH scavenging activity and α-amylase inhibitory activity (R (2) = 0.8967).

A prospective study of pulmonary function test in obese patients

Background: Obesity is considered to affect the respiratory functions. The objective was to study the pulmonary function test and its correlation with smoking, hypertension and diabetes in obese patients with Body Mass Index (BMI) ≥30 kg/m 2 Methods: A cross sectional study was done on 100 patients with age >18 years and Body Mass Index (BMI) ≥30 kg/m 2 in the Department of Medicine, GR Medical College, Gwalior during the period between July 2013 to November 2014. After thorough history and clinical examination of all the selected patients, they were subjected to routine investigation and spirometry (Pulmonary function test). Pulmonary Function Test (PFT) was performed by using UNI-EM spirometer. Results: Out of 100 patients, 37% were in the age group of 41-50 years followed by 27% in 31-40 years and there was a female predominance (53%). Abnormal PFT was found in 58% patients, out of which the commonest pattern was restrictive (32%) followed by mixed pattern (26%). Among females with abnormal PFT restrictive and mixed type pattern were seen in 32% and 18.9% respectively whereas among males 32% and 34% had restrictive and mixed pattern of abnormal PFT respectively. It was found that abnormal PFT pattern was directly proportional to increase in BMI. The mean Forced Vital Capacity (FVC) was 77.76 ± 15.56 L, mean Forced Expiratory Volume in one second (FEV1) was 77.97 ± 17.40 L while mean FEV1/FVC ratio was 105.44 ± 7.85 in the study population. Most common PFT pattern seen in smokers was mixed type (55%). Among hypertensive patients 42.1% had normal PFT. Conclusions: More than half of obese patients were having abnormal PFT in our study, and the increase in BMI was associated with increase in abnormal PFT pattern. The most common abnormal function was restrictive pattern as reflected by decreased mean FVC, FEV1 and increased FEV1/FVC ratio. There was no correlation between hypertension and pulmonary function test in obese; similarly no correlation was seen between diabetes and PFT in obese.

Differential inhibition of CYP1-catalyzed regioselective hydroxylation of estradiol by berberine and its oxidative metabolites

Berberine is a pharmacologically active alkaloid present in widely used medicinal plants, such as Coptis chinensis (Huang-Lian). The hormone estradiol is oxidized by cytochrome P450 (CYP) 1B1 to primarily form the genotoxic metabolite 4-hydroxyestradiol, whereas CYP1A1 and CYP1A2 predominantly generate 2-hydroxyestradiol. To illustrate the effect of berberine on the regioselective oxidation of estradiol, effects of berberine and its metabolites on CYP1 activities were studied. Among CYP1s, CYP1B1.1, 1.3 (L432V), and 1.4 (N453S)-catalyzed 4-hydroxylation were preferentially inhibited by berberine. Differing from the competitive inhibition of CYP1B1.1 and 1.3, N453S substitution in CYP1B1 allowed a non-competitive or mixed-type pattern. An N228T in CYP1B1 highly decreased its activity and preference to 4-hydroxylation. A reverse mutation of T223N in CYP1A2 retained its 2-hydroxylation preference, but enhanced its inhibition susceptibility to berberine. Compared with berberine, metabolites demethyleneberberine and thalifendine caused weaker inhibition of CYP1A1 and CYP1B1 activities. Unexpectedly, thalifendine was more potent than berberine in the inhibition of CYP1A2, in which case an enhanced interaction through polar hydrogen-π bond was predicted from the docking analysis. These results demonstrate that berberine preferentially inhibits the estradiol 4-hydroxylation activity of CYP1B1 variants, suggesting that 4-hydroxyestradiol-mediated toxicity might be reduced by berberine, especially in tissues/tumors highly expressing CYP1B1.

Pelvic types as seen in a tropical setting

Cephalo pelvic disproportion is still the leading indication for caesarean section in many developing countries and the contribution of pelvic typology may play some role in this regard. Our objective is to determine the proportion of pelvic types as seen in a tropical setting. A retrospective review of preliminary films of hysterosalpingography of 400 women who underwent the study between January 2000 and December 2007 was reviewed to determine the pelvic typology. Of the 400 films reviewed, 361 (90.3%) were gynaecoid, 36 (9%) were androidc and 3 (0.8%) were andropoid. There was no platypelloid pelvis seen in the films reviewed and a mixed type pattern was not observed in this study. The proportion of pure gynaecoid pelvis seen in this review is about the highest reported in the literature.

Kinetics of the inhibition of renin and angiotensin I-converting enzyme by flaxseed protein hydrolysate fractions

Enzymatic hydrolysates from flaxseed protein were investigated for in vitro inhibition of angiotensin I-converting enzyme (ACE) and renin activities. Pepsin, ficin, trypsin, papain, thermolysin, pancreatin and Alcalase were used to hydrolyze flaxseed proteins followed by fractionation using ultrafiltration to isolate low-molecular-weight peptides, and separation of the Alcalase hydrolysate into cationic peptide fractions. Using N-(3-[2-furyl]acryloyl)-phenylalanylglycylglycine as substrate, the protein hydrolysates showed a concentration-dependent ACE inhibition (IC 50, 0.0275–0.151 mg/ml) with thermolysin hydrolysate and Alcalase cationic peptide fraction I (FI) showing the most potent activity. Flaxseed peptide fractions also showed no or moderate inhibitory activities against human recombinant renin (IC 50, 1.22–2.81 mg/ml). Kinetics studies showed that the thermolysin hydrolysate and FI exhibited mixed-type pattern of ACE inhibition whereas cationic peptide fraction II inhibited renin in uncompetitive fashion. These results show that the protein components of flaxseed meal possess peptide amino acid sequences that can be exploited as potential food sources of anti-hypertensive agents.

Differential polarization of immune responses by genetic cotransfer of chemokines changes the protective immunity of DNA vaccine against pseudorabies virus

Chemokines play a key role in eliciting adaptive immune responses by selectively attracting the innate cellular components to the site of antigen presentation. To evaluate the effect of the genetic adjuvant of chemokines on the adaptive immune responses induced by a plasmid DNA vaccine expressing glycorotein B (gB) of the pseudorabies virus (PrV), a PrV DNA vaccine was co-inoculated with plasmid DNA expressing certain chemokines including CCL3 (MIP-1alpha), CCL4 (MIP-1beta), CCL5 (RANTES), CXCL8 (MIP-2), and CXCL10 (IP-10). A co-injection of the CCL3 plasmid DNA induced immunity that was biased to the T helper type 2 (Th2) pattern, as judged by the ratio of immunoglobulin G isotypes and the production of interleukin-4 cytokine generated from stimulated immune T cells. However, CCL5 and CXCL10 induced immune responses of the Th1-type, which rendered the recipients more resistant to a virulent virus infection. CXCL8 also showed enhanced humoral and cell-mediated immunity (mixed-type pattern) providing effective protection against a viral challenge. However, there was no change in the immune responses induced by the PrV DNA vaccine in CCL4 recipients. These results suggest that co-injection of a chemokine, in the form of an adjuvant preparation, causes a rebalancing of the immunity, which subsequently affects the protective efficacy against a virulent virus infection.

2,3-di-O-tetradecyl-1-O-(β-d-glucopyranosyl)-sn-glycerol is a substrate for human glucocerebrosidase

Glucocerebrosidase, the lysosomal enzyme that is deficient in patients with Gaucher's disease, hydrolyses non-physiological aryl beta-D-glucosides and glucocerebroside, its substrate in vivo. We document that 2,3,-di-O-tetradecyl-1-O-(beta-D-glucopyranosyl)-sn-glycerol (2,3,-di-14:0-beta-Glc-DAG) inhibits human placental glucocerebrosidase activity in vitro (Ki 0.18 mM), and the nature of inhibition is typical of a mixed-type pattern. Furthermore, 2,3-di-14:0-beta-Glc-DAG was shown to be an excellent substrate for the lysosomal beta-glucosidase (Km 0.15 mM; Vmax. 19.8 units/mg) when compared with the natural substrate glucocerebroside (Km 0.080 mM; Vmax. 10.4 units/mg). The observations that (i) glucocerebrosidase-catalysed hydrolysis of 2,3-di-14:0-beta-Glc-DAG is inhibited by conduritol B epoxide and glucosylsphingosine, and (ii) spleen and brain extracts from patients with Gaucher's disease are unable to hydrolyse 2,3-di-14:O-beta-Glc-DAG demonstrate that the same active site on the enzyme is responsible for catalysing the hydrolysis of 4-methylumbelliferyl beta-D-glucopyranoside, glucocerebroside and 2,3-di-14:O-beta-Glc-DAG. With the aid of computer modelling we have established that the oxygen atoms in 2,3-DAG-Glc at the C-1, C-4*, C-5* (the ring oxygen in glucose) and C-2 positions correspond topologically to the oxygens at C-1, C-4* and C-5* and the nitrogen atom attached to C-2 respectively in glucocerebroside (* signifies a carbon atom in glucose); furthermore, all of the distances with respect to overlap of corresponding heteroatoms range from 0.02 A to 0.77 A (0.002-0.077 nm). A root-mean-square deviation of 0.31 A (0.031 nm) was obtained when the energy-minimized structures of 2,3-di-14:O-beta-Glc-DAG and glucocerebroside were compared using the latter four heteroatom co-ordinates.

Relationship between structure and T-lymphocyte maturation in human thymomas. Enzyme histochemical and immunohistological studies.

Twenty-six human thymomas were studied in an attempt to correlate their morphological appearance with the type and degree of T-lymphocyte maturation, as determined by acid alpha-naphthyl-acetate esterase (ANAE) activity and immunological analysis. Four normal human thymuses were used for purposes of comparison. Two morphological patterns were identified in the thymomas. The distinction was based largely on similarities between the neoplastic epithelial cells and normal cortical and medullary epithelial cells, and on the relative proportions of epithelial cells and lymphocytes. By these criteria "medullary" and "cortical" patterns were identified. In several thymomas both patterns were present in the same tumor ("mixed-type pattern"), producing alternating dark cortical-like areas and lighter foci of medullary differentiation. A good correlation was found between the two patterns and the phenotype of the T-associated lymphoid component. ANAE activity, which was completely lacking in normal cortical thymocytes, was almost absent in the phenotypically immature T-cells of cortical-type thymomas. By contrast, in the medullary-type thymomas, T-cells showed immunological features in common with medullary thymocytes. This was characterized by strong ANAE activity in the majority of cells with a staining pattern corresponding to that of peripheral T-lymphocytes. In addition, most of the proliferating epithelial cells in medullary-type thymomas stained strongly with anti-cytokeratin and anti-epidermal-type keratin antisera. In the mixed-type thymomas the epithelial cell morphology and the immunohistochemical and enzymic features of the T-cells were found to be closely related to the respective cortical--or medullary-like areas. It was concluded that the various characteristics of normal thymic cortex and medulla studied are also present in thymomas. In particular, in medullar-type thymomas the presence of many of the features of normal thymic medulla, such as a squamous cell component, macrophages and interdigitating reticulum cells, may constitute a microenvironment which operates actively in T-cell education. This may account for the functional activities, characteristic of peripheral T-lymphocytes, which T-lymphocytes attain in these thymomas.

Human brain monoamine oxidase: Solubilization and kinetics of inhibition by octylglucoside

Complete solubilization of both the A and B forms of human brain monoamine oxidase (MAO) occurred when crude mitochondria were incubated in the presence of 50 m m octylglucoside (OG). Upon removal of this nonionic detergent by dialysis, approximately 100% of the starting activity was present in the dialysate. The effects of solubilization were examined by comparison of several properties of the membrane-bound and OG-treated oxidases. The percentage inhibition of phenylethylamine (PEA) and the 5-hydroxytryptamine (5-HT) deamination by deprenyl and clorgyline were identical. The K m values obtained for the deamination of PEA, a B-selective substrate, 5-HT, an A-selective substrate, and tyramine (TYR), a nonselective substrate, were also comparable. OG was found to inhibit type A ( I 50 = 8.1 mM) and B ( I 50 = 4.7 mM) MAO activities at concentrations at least 10-fold below those used to solubilize the oxidases. Kinetic studies revealed that OG was an apparent competitive inhibitor of PEA deamination whereas OG produced a mixed-type pattern of inhibition when 5-HT was the variable substrate. Inhibition of TYR deamination by either the A or B form of MAO produced a mixed pattern of inhibition. The findings herein suggest that solubilization of the A and B forms of MAO by OG does not significantly alter the substrate and inhibitor specificity of the oxidases following removal of detergent. However, in the presence of concentrations of OG 50 times less than the critical micellar concentration of this detergent, marked inhibition of deamination by both forms of human brain MAO is observed. Accordingly, the usefulness of OG is limited to situations where the detergent is completely removed before quantitation of MAO activity.

The etiology of toxic peripheral neuropathies: In vitro effects of acrylamide and 2,5-hexanedione on brain enolase and other glycolytic enzymes

The in vitro effects of the neurotoxic compounds, acrylamide and 2,5-hexanedione, on several glycolytic enzymes including enolase, phosphofructokinase (PFK), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactic dehydrogenase (LDH) were studied in rat brain. A differential sensitivity of the enzymes to the inhibitory effects of the neurotoxins was observed. The order of increasing sensitivity to 2,5-hexanedione was enolase -- GAPDH -- PFK and to acrylamide the order was PFK -- enolase -- GAPDH. Neither neurotoxin inhibited LDH. The inhibition of enolase by acrylamide exhibited a mixed type pattern in double reciprocal plots. The inhibition could be completely reversed by dialysis indicating that it did not involve covalent bond formation. In the presence of dithiothreitol (DTT) or glutathione the inhibition of enolase by either acrylamide or 2,5-hexanedione was potentiated. Activity of enolase inhibited by both acrylamide and DTT could not be restored to pre-inhibition rates following dialysis indicating that an irreversible interaction between acrylamide and enolase had taken place. The results suggest that neurotoxic compounds which produce distal axonopathies have a common pattern of attack on glycolytic enzymes and that interruption of glycolysis is the underlying biochemical basis for both the physiological and morphological damage caused by these compounds.