Detection of neutral protease (Periocheck) and BANA hydrolase (Perioscan) compared with traditional clinical methods of diagnosis and monitoring of chronic inflammatory periodontal disease

Abstract Perioscan requires a plaque sample to detect the presence of enzymes capable of degrading N-benzoyl-DL-arginine-2-naphthylamide (BANA) from relatively few anaerobic periodontal pathogens. Periocheck assays the presence of neutral proteases in crevicular fluid. The aim of this study was to compare these test kits with traditional clinical methods of detecting periodontal disease and to monitor the ability of the kits to reflect the response to initial therapy. 19 patients with moderately severe chronic periodontitis were seen before and after a course of oral hygiene and root instrumentation consisting of 4 appointments. Clinical measurements and test assays were collected at 5 diseased sites and 2 healthy sites in each subject. Complete data from 125 sites were available for statistical analysis. At baseline Periocheck had a sensitivity of 88% and a specificity of 61% whereas Perioscan had a sensitivity of 99% and a specificity of 55%, when related to the clinical diagnosis. A composite clinical assessment, based on improvement or deterioration of one whole unit change of the subjective clinical indices and 2mm changes or greater in probing depth or probing attachment level, revealed 75 sites which improved following treatment, whereas 45 sites did not change and 5 sites deteriorated. The probability that the tests agreed with the clinical outcome after treatment, was calculated as 50.4% for Periocheck and 52% for Perioscan. The diagnostic kits did not reliably reflect the clinical assessment of periodontal disease in the cross sectional study, or the outcome following treatment.     

Mutational specificity of the syn 1,2-dihydrodiol 3,4-epoxide of 5-methylchrysene

The mutational specificity of the syn dihydrodiol epoxide of 5-methylchrysene in the supF gene of the pSP189 vector was examined. Transversion mutations at GC pairs predominated with G → T and G → C changes accounting for 42 and 21% of total base change mutations. The types of mutations found reflect the previously determined chemical preference of this reactive species for reaction with deoxyguanosine residues in DNA.     

Lysosomal abnormalities in degenerating neurons link neuronal compromise to senile plaque development in Alzheimer disease

Antibodies to the lysosomal hydrolases, cathepsins B and D and β-hexosaminidase A, revealed alterations of the endosomal-lysosomal system in neurons of the Alzheimer disease brain, which preceded evident degenerative changes and became marked as atrophy, neurofibrillary pathology, or chromatolysis developed. At the earliest stages of cell atrophy, hydrolase-positive lysosomas accumulated at the basal pole and then massively throughout the perikarya and proximal dendrites of affected pyramidal neurons in Alzheimer prefrontal cortex and hippocampus, far exceeding the changes of normal aging. Secondary lysosomes as well as tertiary residual bodies (lysosomes/lipofuscin) increased implying stimulated, autophagocytosis and lysosomal system activation. Less affected brain regions, such as the thalamus, displayed similar though less extensive alterations. Certain thalamic neurons exhibited a distinctive lysosome-related abnormality characterized by the presence of cell surface blebs of varying size and number filled with intense hydrolase immunoreactivity. At more advanced stages of degeneration in still intact neurons, hydrolase-positive lipofuscin, particularly in the form of abnormal large aggregates, nearly filled the cytoplasm. Similar lipofuscin aggregates were oberved in abundance in the extracellular space following cell lysis and were usually associated with deposits of the β-amyloid protein. Degenerating neurons and their processes were the major source of these aggregates within senile plaques which contained high concentrations of acid hydrolases. We have shown in previous studies that these lysosomal hydrolases in plaques are enzymatically-active. The persistence of lysosomal structures in the brain parenchyma after neurons hyve degenerated is a striking and potentially diagnostic feature of Alzheimer disease which has not been observed, to our knowledge, in other degenerative diseases. The lysosomal response in degerating Alzheimer neurons represents a probable link between an early activation of the lysosomal system in at-risk, normal-appearing neurons and the end-stage contribution of lysosomes to senile plaque formation of emphasizes a slowly progressive disturbance of the lysosomal system throughout the development of Alzheimer disease.     

Antibodies to the pesticide interaction sites of parathion hydrolase and cutinase

Monoclonal antibodies are able to provide information on the surface topography of biopolymers. Antibodies capable of inhibiting the activities of cutinase and parathion hydrolase have been identified in order to probe the sites of pesticide inhibition. Kinetic studies were employed to determine whether organophosphate pesticide binding was directly prevented by antibody binding. Prior binding of chlorfenvinphos and methyl paraoxon to cutinase inhibited subsequent binding by the monoclonal anti‐cutinase antibodies. The role of antibodies in probing enzyme structure is discussed.     

Stereochemical considerations on the inhibition of hepatic epoxide hydrolase by some pesticides and their epoxides

The present studies identify the steric factors involved in the hydration of epoxide intermediates of some pesticides by hepatic epoxide hydrolase. Investigations were carried out regarding the formation of reactive epoxide intermediates and their different interactions with the hepatic epoxide hydrolase. Some pesticides and their parent epoxides were selected on he basis of the steric hindrance on the oxirane ring. The results indicate that the inhibition of this enzyme depends on the steric hindrance produced by substituents on the oxirane ring of these pesticides. Mono- and di-substituted oxiranes are good substrates of the epoxide hydrolase and non-competitive inhibitors of the hydration of styrene oxide, while tri-substituted epoxides are virtually inactive on inhibiting the hepatic epoxide hydrolase activity.     

依达拉奉联合瑞舒伐他汀治疗心源性脑梗死的疗效及对血清CXCL12、UCH-L1、HC-gp39水平的影响

目的 探究依达拉奉联合瑞舒伐他汀治疗心源性脑梗死的疗效及对血清趋化因子12（CXCL12）、泛素C末端水解酶L1（UCH-L1）、人类软骨糖蛋白-39（HC-gp39）水平的影响。方法 选取2020年3月—2022年4月达州市中心医院收治的90例心源性脑梗死患者作为研究对象,随机分为对照组和观察组,各45例。对照组给予瑞舒伐他汀治疗,观察组给予依达拉奉联合瑞舒伐他汀治疗。比较两组疗效、CXCL12、UCH-L1、HC-gp39、血液流变学指标、血脂水平及美国国立卫生研究院脑卒中量表（NIHSS）评分。结果 观察组总有效率高于对照组（P <0.05）。观察组治疗前后血清CXCL12、UCH-L1、HC-gp39水平的差值高于对照组（P <0.05）。观察组治疗前后全血低切黏度、全血高切黏度及纤维蛋白原水平的差值高于对照组（P <0.05）。观察组治疗前后TC、TG、LDL-C水平的差值高于对照组（P <0.05）。观察组治疗前后NIHSS评分的差值高于对照组（P <0.05）。结论 依达拉奉联合瑞舒伐他汀治疗心源性心肌梗死可有效提高患者临床疗效,改善血液流变学指标、血脂、神经功能及炎症反应。     

Four new adenosine deaminase mutations,altering a zinc-binding histidine,two conserved alanines,and a 5′ splice site

Three new missense mutations (H15D, A83D, and A179D) and a new splicing defect (573 + 1G→A) in the 5′ splice site of intron 5 were among six mutant adenosine deaminase (ADA) alleles found in three unrelated patients with severe combined immunodeficiency disease, the most common phenotype associated with ADA deficiency. When expressed in vitro, the H15D, A83D, and A179D proteins lacked detectable ADA activity. The splicing defect caused skipping of exon 5, resulting in premature termination of translation and a reduced level of mRNA. H15D is the first naturally occurring mutation of a residue that coordinates directly with the enzyme-associated zinc ion. Molecular modeling based on the atomic coordinates of murine ADA suggests that the D15 mutation would create a cavity or gap between the zinc ion and the side chain carboxylate of D15. This could alter the ability of zinc to activate a water molecule postulated to play a role in the catalytic mechanism. A83 and A179 are not directly involved in the active site, but are conserved residues located respectively in a helix 4 and β strand 4 of the α/β barrel. Replacement of these small hydrophobic Ala residues with the charged, more bulky Asp side chain may distort ADA structure and affect enzyme stability or folding.© 1995 wiley-Liss, Inc.     

Epoxide hydrolases in the rat epididymis: possible roles in xenobiotic and endogenous fatty acid metabolism.

Epoxide hydrolases play an important role in detoxifying epoxides that arise from the metabolism of xenobiotic and endogenous compounds. Both the soluble and microsomal forms of epoxide hydrolase (sEH and mEH, respectively) have been detected in the rat testis. Because of the important role the epididymis plays in sperm maturation and protection, the present study evaluated the presence and activity of these two epoxide hydrolases in the rat epididymis. Using Western blotting, protein bands consistent in size with both mEH and sEH were detected in the caput, corpus, and cauda of the epididymis. The mEH immunoreactive bands in the epididymis ( approximately 50 kDa) were consistent with mEH detected in the liver and kidney. The sEH immunoreactive bands in the epididymis ( approximately 65 kDa) were consistent with a recombinant sEH standard and sEH detected in the liver, kidney, and testis. The presence of mEH and sEH in the epididymis was supported by observations from substrate-based enzyme assays. Results indicated that epididymal mEH can hydrolyze [(3)H]-cis-stilbene oxide to the corresponding diol at levels approximately 9% of the kidney. Epididymal sEH hydrolyzed the substrate [(3)H]-trans-diphenylpropene oxide to the corresponding diol and this activity was inhibited by cyclohexyl-dodecyl urea. Arachidonic acid epoxygenase activity was detected in epididymal S9 fractions, suggesting that fatty acid metabolism by epididymal cytochrome P450s can form epoxides that subsequently become substrates for epididymal sEH. Results from the present study indicate that the epididymis contains at least two active forms of epoxide hydrolase. The role of these enzymes in the detoxification of xenobiotic epoxides is well known, although it is unclear what cellular role they may play in the formation of biologically active metabolites in the epididymis.