Biomedical subjects

K Hirai

Publications and source records attributed to K Hirai.

At least 109 records · Page 6Linked to original sources

PubMed2000

Equine herpesvirus 9 induced lethal encephalomyelitis in experimentally infected goats.

The pathogenicity of a new neurotropic equine herpesvirus 9 (EHV-9) formerly designated gazelle herpesvirus 1 was evaluated using the goat as a representative of domesticated ruminants. Two goats inoculated intranasally with EHV-9 showed salivation, teeth grinding and other neurological disorders on day 8 post inoculation. One goat died 30 min after the onset of clinical signs and the other was sacrificed 3 h after the sudden onset of teeth grinding and foamy salivation. EHV-9 was recovered from peripheral white blood cells, the olfactory bulbs and brain, nasal swabs, concha, and lungs. Neuropathological lesions were located in the olfactory bulbs, cerebrum, midbrain and medulla oblongata with degeneration and necrosis of neurons, rarefaction, perivascular infiltration of mononuclear cells, and nodal glial reaction. EHV-9 antigen was detected in neurons in the lesions. These findings indicated that EHV-9 is highly pathogenic with high neurotropism for goats.

Animals↗

PubMed2000

Classification of female urinary incontinence by the scored incontinence questionnaire.

OBJECTIVES: Our purpose was to investigate whether urinary incontinence (UI) severity could be graded by UI scores. METHODS: The study included 168 UI patients diagnosed by conventional procedures as stress incontinence (SI, n=108) or urge incontinence (URI, n=60). A questionnaire containing 15 items scored for stress-score (s-s) and urge-score (u-s) was administered to patients to assess the correlation between pad test values (PTVs) and s-s in SI and u-s in URI. RESULTS: Significant correlations were found between log[PTVs] and both s-s and u-s: log[PTV(SI)]=0.051s-s-0.207 (r=0.830, P<0.0001) and log[PTV(URI)]=0.064u-s-0.459 (r=0.827, P<0. 0001). Based on theoretical PTVs obtained using these equations, s-s of 26-24, 23-18, and 17-10 in SI were equivalent to severe, moderate, and mild, respectively, and u-s of 22-19 and 18-12 in URI were equivalent to moderate and mild, respectively, according to the classification of the International Continence Society. CONCLUSION: The UI score should be a simple and useful procedure for use by general gynecologists to grade UI severity clinically.

Aged↗

PubMed2000

The urinary incontinence score in the diagnosis of female urinary incontinence.

OBJECTIVE: Our purpose was to determine whether the urinary incontinence (UI) score is significantly useful in evaluating the clinical status of UI. METHOD: The questionnaire was administered to 198 UI patients (27-73 years of age) diagnosed by conventional procedures. It consisted of 15 questions, and the answers were assigned points divided into a stress score (s-s) and urge score (u-s) according to severity. RESULTS: The patients were classified into a stress incontinence group (SI; 125 cases), urge incontinence group (URI; 29 cases), mixed incontinence group (MI; 41 cases), and overflow incontinence group (3 cases). Classification by questionnaire yielded 110 SI cases, 31 URI cases, and 46 MI cases, accuracy of 83.2%, 86.2%, and 61.0%, respectively. A significant correlation was observed with s-s of SI (r = 0.669, P < 0.001) and u-s of URI (r = 0.583, P < 0.005). CONCLUSION: The UI score will be a simple, clinically effective diagnostic procedure for UI for use by general gynecologists.

Adult↗

PubMed2000

Cyclopentene dialdehydes from Tabebuia impetiginosa.

The isolation of two cyclopentene dialdehydes, 2-formyl-5-(4'-methoxybenzoyloxy)-3-methyl-2-cyclopentene-1-acetal dehyde, and 2-formyl-5-(3', 4'-dimethoxybenzoyloxy)-3-methyl-2-cyclopentene-1-acetaldehyde, from the bark of Tabebuia impetiginosa is reported. The structures were established by analysis of spectroscopic data. These compounds showed anti-inflammatory activity.

Aldehydes↗

PubMed2000

Chemokine production by the BEAS-2B human bronchial epithelial cells: differential regulation of eotaxin, IL-8, and RANTES by TH2- and TH1-derived cytokines.

BACKGROUND: Bronchial epithelial cells produce many types of chemokines and may contribute to lung inflammation by recruiting inflammatory cells. The CC chemokine eotaxin is a potent, eosinophil-specific chemoattractant that has been detected in the bronchial epithelium of patients with asthma. OBJECTIVES: The aim of this study was to investigate the regulatory mechanisms of chemokine production from bronchial epithelium by inflammatory cytokines, especially T(H)2- and T(H)1-derived cytokines, in bronchial asthma. METHODS: BEAS-2B human bronchial epithelial cells were cultured with TNF-alpha, IL-4, IL-13, and IFN-gamma alone or in combination, after which supernatants were assayed for eotaxin, IL-8, and RANTES proteins with ELISA. Reverse transcription-PCR was also performed. RESULTS: TNF-alpha induced production of eotaxin, IL-8, and RANTES in a concentration-dependent manner. Both IL-4 and IL-13 synergistically enhanced TNF-alpha-induced eotaxin production, whereas IL-8 production induced by TNF-alpha was significantly down-regulated by the T(H)2-derived cytokines. IFN-gamma, a T(H)1 cytokine, counteracted the enhancing effects of IL-4 and IL-13 on eotaxin production. RANTES production by TNF-alpha was not affected by IL-4 and IL-13 but was markedly enhanced by IFN-gamma. CONCLUSIONS: These results suggest that T(H)2 cytokines are involved in preferential recruitment of eosinophils in bronchial asthma by enhancing eotaxin and reducing IL-8 production from bronchial epithelial cells and that T(H)1 cytokines counteract the effects of T(H)2 cytokines by reducing eotaxin production.

Bronchi↗

PubMed2000

Macrolides and clindamycin suppress the release of Shiga-like toxins from Escherichia coli O157:H7 in vitro.

We investigated the effects of antimicrobial agents fosfomycin (FOS), cefdinir (CDIN), levofloxacin (LEVX), rokitamycin (ROK), roxithromycin (ROX), and clindamycin (CLI) on the release of Shiga-like toxins (SLTs) by enterohaemorrhagic Escherichia coli (EHEC). EHEC was cultured for 14 h in the presence of ROX, ROK or CLI at sub-minimum inhibitory concentrations (subMICs) of 1.56-6.25 mg/l, followed by assay of the level of SLTs in the supernatants using cytotoxicity assay and reversed passive latex agglutination method. Exposure to ROX, ROK or CLI reduced the amount of released SLTs compared with untreated control cultures (P<0.05). These agents however, did not decrease the number of viable EHEC, indicating the importance of bactericidal agents. When the bacteria was exposed to CDIN, FOS or LEVX, the level of SLTs in the culture supernatant increased with the destruction of bacterial cells in the order of CDIN, FOS, LEVX. When 0.5 mg/l of LEVX was added to cultures with or without pretreatment using ROX, ROK, or CLI, the release of SLTs was reduced by this pretreatment (P<0.05). These results may have clinical implications for the treatment of EHEC infection.

Animals↗

PubMed2000

Eotaxin in induced sputum of asthmatics: relationship with eosinophils and eosinophil cationic protein in sputum.

BACKGROUND: Eosinophilic inflammation is a crucial aspect of allergic diseases such as bronchial asthma. An eosinophil-active chemokine, eotaxin, may play a role in the pathogenesis of the tissue eosinophilia accompanying asthma. METHODS: Induced sputa were obtained from 53 patients with atopic asthma and six healthy subjects, and the concentration of eotaxin in the sputum was measured by ELISA. We investigated whether the sputum content of eotaxin is related to 1) asthma status or corticosteroid therapy, and 2) other sputum indices, including percentage of eosinophils and concentration of eosinophil cationic protein (ECP). RESULTS: The patients with stable or unstable asthma showed significantly higher concentrations of sputum eotaxin than the normal controls. The level of sputum eotaxin demonstrated a positive correlation with the percentage of eosinophils in stable asthmatics not receiving corticosteroid therapy, but not in stable patients treated with corticosteroids, or in unstable patients. Sputum eotaxin demonstrated a positive correlation with ECP in asthmatic patients who were either in a stable state or not receiving steroid therapy. CONCLUSIONS: The elevated level of eotaxin detected in association with increased eosinophils and ECP in the sputum of asthmatics suggests that eotaxin is involved in the pathogenesis of eosinophilic airway inflammation. The relationship of eotaxin to airway eosinophilia may be modified by the stability status of asthma and corticosteroid therapy.

Adult↗

PubMed2000

Elevated levels of eotaxin and interleukin-5 in blister fluid of bullous pemphigoid: correlation with tissue eosinophilia.

BACKGROUND: Bullous pemphigoid (BP) often provokes blood and tissue eosinophilia, which suggests that some chemoattractants modulate the eosinophil infiltration in BP. Eotaxin, a CC chemokine, strongly attracts eosinophils, and interleukin (IL)-5 induces eosinophil differentiation, proliferation and colony formation in vitro. OBJECTIVES: To examine the correlation between levels of eotaxin and IL-5 and the number of lesional eosinophils, and the expression of eotaxin in BP lesions. PATIENTS/METHODS: In this study we measured eotaxin and IL-5 levels in blister fluid of BP by enzyme-linked immunosorbent assay. We also examined the expression of eotaxin in BP lesions by immunohistochemistry. RESULTS: Both eotaxin and IL-5 were detected at high levels in BP blister fluid. Blister fluid eotaxin, but not IL-5 levels, correlated significantly with the number of dermal infiltrating eosinophils. By immunohistochemistry, eotaxin was strongly expressed in epidermal keratinocytes around BP blisters. CONCLUSIONS: These findings suggest that eotaxin and IL-5 are strongly associated with the tissue eosinophilia of BP. Therapies which aim to inhibit production of eotaxin and IL-5 may improve the inflammation and blister formation in BP.

Adult↗

PubMed2000

Fas-mediated apoptosis of peripheral blood mononuclear cells in patients with hepatitis C.

In the present study, we demonstrated that a close relationship exists between hepatitis C virus (HCV) infection of peripheral blood mononuclear cells (PBMCs) and cell-surface Fas expression in patients with hepatitis C, and showed the possibility of PBMCs apoptosis via a Fas-mediated system. The expression of Fas on PBMCs was found by flowcytometric analysis to be significantly increased in these patients. In addition, the treatment of patients' PBMCs with anti-Fas antibody induced cell death, with nuclear condensation and fragmentation and cellular DNA fragmentation. These data indicate that the patients' PBMCs expressed a large amount of functional Fas on the cell surface and were susceptible to stimulation against Fas, causing apoptotic cell death. We then quantified the serum-soluble Fas ligand (sFasL), which was known to bind to Fas and induce the apoptotic signals into the sensitized cells. The patients' serum sFasL levels were significantly higher than those of normal subjects and showed a good negative correlation with their PBMC number. To demonstrate the correlation between Fas expression and HCV infection, nested reverse transcriptase polymerase chain reaction (RT-PCR) was performed to detect HCV RNA. Interestingly, HCV RNA was preferentially detected from Fas-positive cells but not from Fas-negative cells, which had been isolated from PBMCs by magnetic beads. These results suggest that HCV infection of PBMCs might induce Fas expression and additional stimulation such as sFasL might induce apoptosis in these Fas-expressing cells. These mechanisms, in addition to hypersplenism, may explain the decrease in the number of PBMCs observed in patients with chronic hepatitis C.

Adult↗

PubMed2000

Interleukin-13 and tumour necrosis factor-alpha synergistically induce eotaxin production in human nasal fibroblasts.

BACKGROUND: There is increasing evidence that eotaxin is a key mediator in the development of tissue eosinophilia. However, the mechanism involved in the production of eotaxin has yet to be clarified. Most recently, it has been shown that interleukin (IL) -4 induces eotaxin in dermal fibroblasts. A novel cytokine termed IL-13, which binds to the alpha-chain of the IL-4 receptor, shares many biological activities with IL-4. It is known that fibroblasts express the IL-4 receptor and produce collagen type I upon stimulation with IL-4. OBJECTIVE: We investigated whether IL-13, as well as IL-4, are able to induce eotaxin production in human nasal mucosal fibroblasts (HNMFs). Furthermore, we investigated the effect of costimulation of IL-13 and TNFalpha on eotaxin production. METHODS: HNMFs, isolated from inferior nasal mucosa samples, were stimulated by various kind of cytokines for 1-36 h at 37 degrees C in 5% CO2. The change in the expression of eotaxin mRNA was then evaluated by reverse transcriptase-polymerase chain reaction and the Southern blot analysis. The amount of eotaxin in the culture media was measured by ELISA. RESULTS: IL-13 as well as IL-4 dose-dependently induced eotaxin expression in HNMFs. Furthermore, IL-13 and TNFalpha synergistically induced eotaxin expression in HNMFs, while they hardly induced eotaxin expression in endothelial cells, epithelial cells or eosinophils. The synergy was observed when pre-incubation of HNMFs with IL-13 was followed by a stimulation with TNFalpha, or HNMFs were simultaneously stimulated with IL-13 and TNFalpha. CONCLUSION: These results strongly indicate that IL-13, as well as IL-4, may be important in eotaxin-mediated eosinophilic inflammation in nasal mucosa. In addition, in nasal mucosa, fibroblasts are the major cell source for eotaxin.

Adult↗

PubMed2000

Cerebrospinal fluid somatostatin levels in febrile seizures and epilepsy in children.

We analysed the level of cerebrospinal fluid (CSF) somatostatin in children with febrile seizures and epilepsy. In the febrile seizure group (n = 23), the somatostatin level was 83.9 +/- 11.2 pg/ml, which was significantly higher than that of age-matched controls. CSF samples obtained within 3 h of the last seizure had higher somatostatin levels (106.1 +/- 12.4 pg/ml;n = 14) than did the CSF obtained after 3 h (49.4 +/- 15.6 pg/ml;n = 9). The mean somatostatin level in the epilepsy group was 35.3 +/- 4.3 pg/ml (n = 34), and was distributed as follows: 27.6 +/- 3.6 pg/ml in the idiopathic generalized epilepsy group (n = 16), 44.0 +/- 9.4 pg/ml in the symptomatic generalized epilepsy group (n = 13), and 37.2 +/- 10.1 pg/ml in the partial epilepsy group (n = 5). The levels in each group were significantly higher than those in age-matched controls. Somatostatin is a hypothalamic tetradecapeptide with excitatory effects on neurons in children with febrile seizures and epilepsy. The finding that patients with convulsive disease had elevated levels of CSF somatostatin suggests that somatostatin release is somehow related to seizure activity. It remains to be determined whether this is due to increased release from over-active excitatory neurons or leakage from damaged or anoxic neurons, secondary to seizure activity.

Adolescent↗

PubMed2000

Chemokines induce eosinophil degranulation through CCR-3.

BACKGROUND: Such CC chemokines as eotaxin and RANTES induce preferential eosinophil recruitment in allergic inflammation. They also elicit proinflammatory effector functions of eosinophils, such as enhanced adhesion and superoxide generation. Eosinophil degranulation by chemokines, however, has not been studied in detail. OBJECTIVE: The purpose of this study was to identify chemokines and their corresponding receptors that induce eosinophil degranulation by using a panel of chemokines and blocking antibodies to candidate receptors. METHODS: Highly purified eosinophils were preloaded with Fura-2 and stimulated with a panel of chemokine ligands for 14 known chemokine receptors: CCR1 to CCR8, CXCR1 to CXCR4, CX3CR1, and XCR1. Calcium influx was measured with fluorescence spectrometry. Eosinophils were also stimulated with the chemokines in the presence or absence of IL-5, and levels of eosinophil-derived neurotoxin were measured in the supernatant with RIA. Specific antibodies to chemokine receptors were used to block degranulation. RESULTS: Calcium influx was induced by monocyte chemotactic protein (MCP) 1, MCP-3, MCP-4, RANTES, eotaxin, IL-8, and stromal cell-derived factor 1alpha, which are chemokines that bind several chemokine receptors. However, degranulation was induced only by CCR3 ligands, including MCP-3, MCP-4, RANTES, and eotaxin. Priming of eosinophils with IL-5 enhanced CCR3 ligand-induced degranulation but did not cause non-CCR3 ligands to induce eosinophil-derived neurotoxin release. An antibody against CCR3 significantly inhibited degranulation induced by CCR3 ligands, eotaxin, or RANTES. CONCLUSION: These results suggest that chemokine-induced eosinophil degranulation, a major effector of eosinophil functions, is mediated through only CCR3, although some non-CCR3 ligands induce calcium influx in eosinophils. CCR3 may be an important target in the treatment of eosinophilic inflammation.

Calcium↗

PubMed2000

Glucocorticoids preferentially upregulate functional CXCR4 expression in eosinophils.

BACKGROUND: Chemokines play an important role in accumulation of eosinophils at allergic inflammatory sites. Systemic administration of glucocorticoids (GCCs) attenuates tissue eosinophilia. In vivo chemokine actions are regulated at levels of both ligand production and receptor expression. The inhibitory effects of GCCs on the production of eosinophil-active chemokines, such as eotaxin, have been well established. However, no data exist regarding the effects of GCCs on expression of chemokine receptors in eosinophils per se. OBJECTIVE: The objective of this study was to investigate the regulation of chemokine receptor expression in eosinophils by GCCs. METHODS: Chemokine receptor expression was analyzed by using flow cytometry and reverse transcriptase PCR. Intracellular Ca(2+) influx and chemotaxis were also analyzed. RESULTS: Eosinophil CCR3 expression was slightly downregulated by 24-hour treatment with dexamethasone (DEX). On the other hand, DEX-treated eosinophils showed markedly increased CXCR4 expression ( approximately 6 fold) in a time- and dose-dependent fashion. In contrast to eosinophils, CXCR4 expression in neutrophils was only marginally affected by DEX. In DEX-treated eosinophils, stromal cell-derived factor 1alpha, a natural ligand for CXCR4, induced a higher level of Ca(2+) influx and chemotaxis compared with untreated cells. CONCLUSION: GCCs upregulate the expression of CXCR4 in eosinophils but not in neutrophils. Because stromal cell-derived factor 1alpha may play a role in baseline trafficking of eosinophils into extravascular tissues rather than recruiting them directly to inflammatory sites, upregulation of CXCR4 by GCCs may mediate the antiallergic property of these drugs by sequestering eosinophils from the circulation to extravascular tissues.

Apoptosis↗

PubMed2000

Bloody cerebrospinal fluid from patients with subarachnoid hemorrhage alters intracellular calcium regulation in cultured human vascular endothelial cells.

Endothelial cell dysfunction may contribute to cerebral vasospasm and aggravation of ischemic brain damage following subarachnoid hemorrhage (SAH). It has been suggested that oxyhemoglobin derived from subarachnoid blood clots might be a prime candidate for cerebral vasospasm. In this study, cisternal bloody cerebrospinal fluid (bCSF) was collected from SAH patients four and seven days after aneurysmal rupture, and the effects of bCSF on the cell growth and intracellular calcium ion ([Ca2+]i) dynamics were investigated in cultured human umbilical vein endothelial cells. CSF collected from patients undergoing other intracranial surgeries was used as a control. Pre-treatment with bCSF4 significantly facilitated cell proliferation and DNA synthesis in the cultured endothelial cells, and significantly enhanced histamine-induced [Ca2+]i increase, while acute treatment of the bCSF elicited no [Ca2+]i change. Pre-treatment with interleukin-1 beta showed a similar significant enhancement of the histamine-induced [Ca2+]i response, while pre-treatment with high concentrations of serum or interleukin-6 did not change the [Ca2+]i response. It is concluded that bCSF collected from SAH patients contains some substances which enhance endothelial cell proliferation and sensitivity to inflammatory mediator.

Adult↗

PubMed2000

Inhibition of cell growth and Epstein-Barr virus reactivation by CD40 stimulation in Epstein-Barr virus-transformed B cells.

The CD40 molecule plays important roles in B cell activation, proliferation, and immunoglobulin (Ig) class switching. In Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL), CD40 mediates growth inhibition and EBV reactivation via the CD40 signaling pathways. CD40 cross-linking with a monoclonal antibody arrests cell growth in G1 and induces expression of p27kip1 cyclin-dependent kinase inhibitor. CD40 cross-linking also induces EBV reactivation, as detected by the induction of EBV-specific early antigen, immediate early BZLF1 RNA, and its protein product ZEBRA. These results support hypotheses that the proliferation of EBV-infected B cells in vivo can be inhibited by interactions with the CD40 ligand on activated helper T cells, and latent EBV is reactivated via the signaling pathways controlled by CD40 interactions.

Apoptosis↗

PubMed2000

Neuronal oxidative stress precedes amyloid-beta deposition in Down syndrome.

The predictable chronological sequence of pathological events in Down syndrome (DS) provides the opportunity to rigorously investigate the relationship between oxidative stress and amyloid-beta (Abeta) deposition. In this study, we report a marked accumulation of oxidized nucleic acid, 8-hydroxyguanosine (8OHG), and oxidized protein, nitrotyrosine, in the cytoplasm of cerebral neurons in DS with the levels of nucleic acid and protein oxidation paralleling each other. Relative density measurements of neuronal 8OHG immunoreactivity showed that there was a significant increase (p < 0.02) in DS (n = 22, ages 0.3-65 yr) compared with age-matched controls (n = 10, ages 0.3-64 yr). As a function of age, 8OHG immunoreactivity increased significantly in the teens and twenties (p < 0.04), while Abeta burden only increased after age 30 (p < 0.0001). In 9 cases of DS bearing Abeta deposition, the extent of deposits of Abeta ending at amino acid 42 (Abeta42) was actually associated with a decrease in relative 8OHG (r = -0.79, p < 0.015) while Abeta40 was not. These findings suggest that in brains of patients with DS, increased levels of oxidative damage occur prior to the onset of Abeta deposition.

Adolescent↗

PubMed2000

Engineering subtilisin E for enhanced stability and activity in polar organic solvents.

We examined the effect of a novel disulfide bond engineered in subtilisin E from Bacillus subtilis based on the structure of a thermophilic subtilisin-type serine protease aqualysin I. Four sites (Ser163/Ser194, Lys170/Ser194, Lys170/Glu195, and Pro172/Glu195) in subtilisin E were chosen as candidates for Cys substitutions by site-directed mutagenesis. The Cys170/Cys195 mutant subtilisin formed a disulfide bond in B. subtilis, and showed a 5-10-fold increase in specific activity for an authentic peptide substrate for subtilisin, N-succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide, compared with the single-Cys mutants. However, the disulfide mutant had a 50% decrease in catalytic efficiency due to a smaller k(cat) and was thermolabile relative to the wild-type enzyme, whereas it was greatly stabilized relative to its reduced form. These results suggest that an electrostatic interaction between Lys170 and Glu195 is important for catalysis and stability in subtilisin E. Interestingly, the disulfide mutant was found to be more stable in polar organic solvents, such as dimethylformamide and ethanol, than the wild-type enzyme, even under reducing conditions; this is probably due to the substitution of uncharged Cys by charged surface residues (Lys170 and Glu195). Further, the amino-terminal engineered disulfide bond (Gly61Cys/Ser98Cys) and the mutation Ile31Leu were introduced to enhance the stability and catalytic activity. A prominent 3-4-fold increase in the catalytic efficiency occurred in the quintet mutant enzyme over the range of dimethylformamide concentration (up to 40%).

Bacillus subtilis↗

PubMed2000

Enhanced thermostability of the single-Cys mutant subtilisin E under oxidizing conditions.

We obtained enhanced thermostability by replacing Ser161 with Cys in subtilisin E from Bacillus subtilis, a cysteine-free alkaline serine protease. The Ser161Cys mutant subtilisin E was purified from the culture supernatant of the recombinant B. subtilis in an oxidizing environment. SDS-polyacrylamide gel electrophoresis and mass spectrometry under oxidizing conditions indicated that the mutant enzyme in part formed an oligomeric protein, which may contain an intermolecular disulfide bond between two surface Cys residues at position 161. Further, no free sulfhydryl groups were detected in the mutant enzyme, suggesting the sulfhydryl modification in a monomeric form under oxidizing conditions. The Ser161Cys mutant enzyme showed a catalytic efficiency equivalent to that of the wild-type enzyme. The half-life of thermal inactivation of the mutant was found to be 2-4 times longer than that of the wild-type enzyme. The optimum temperature of the mutant was 55 degrees C, which was 5 degrees C higher than that of the wild-type enzyme. Under reducing conditions, however, the characteristics of the mutant enzyme reverted to those of the wild-type enzyme. Similar results were obtained for another Cys mutant as to position 194 (wild-type, Ser), which is the same surface residue as Ser161. Possible reasons for the enhanced thermostability of the single-Cys mutant subtilisins E under oxidizing conditions are discussed in terms of two different mechanisms.

Amino Acid Substitution↗