Injurious status of Schizotetranychus schizopus (Zacher, 1913) (Acari: Tetranychidae) on Indian Thorny Bamboo

2021 ◽  
Vol 26 (2) ◽  
pp. 343-352
Author(s):  
C. P. Vibija ◽  
Ramani Neravathu
Keyword(s):  
Defense Mechanism ◽  
Feeding Activity ◽  
Botanical Garden ◽  
Total Phenol ◽  
Mite Infestation ◽  
Dominant Group ◽  
Total Carbohydrate ◽  
Worldwide Distribution ◽  
Enhanced Production ◽  
Bamboo Leaves

Spider mites, especially members of Schizotetranychus represent a common and dominant group of bamboo pests, enjoying worldwide distribution. The present paper highlights the feeding attributes of a notorious species of bamboo spider mite, viz. Schizotetranychus schizopus (Zacher, 1913) infesting the Indian Thorny Bamboo, Bambusa bambos (L.) Voss. Observations on feeding behavior of the mite were completed in the laboratory by collecting mite specimens from infested leaves of bamboo plants grown in Calicut University Botanical Garden. The species showed initial colonization on the abaxial surface of bamboo leaves, adjacent to the midrib and feeding activity of the members of the colony resulted in the development of damage symptoms like chlorotic spots, white patches, yellowing etc. Comparative analysis of the biochemical constituents of mite infested and uninfested leaves of B. bambos revealed significant alterations. Mite infested bamboo leaves presented significantly reduced values of chlorophyll fluorescence (30.10% loss in Fv/Fm ratio) thereby indicating a decline of photosynthetic efficiency. Significant reduction in total carbohydrate (58.87%) and total protein (21.02%) contents also could be accounted in mite infested leaves. Meanwhile, mite infestation was found to enhance the production of stress compounds such as Total Phenol (22.86%) and Proline (69.05%). An increase in the uptake of micro and macronutrients like Potassium (18.87%), Calcium (36.66%), Copper (48.76%) and Zinc (19.62%) was also observed in mite infested leaves. Despite this, the uptake of nutrients such as Phosphorus (8.22%), Magnesium (3.55%), Sulphur (1.54%), Iron (11.46%), Manganese (13.64%) and Boron (30.09%) significantly decreased owing to mite infestation. Significant decrease in moisture content also was evident in the mite infested bamboo leaves. The results of the study helped to evidence the biotic stress induced by the mite on its bamboo host, by promoting enhanced production of Total Phenol, Proline, Potassium, Calcium, Copper and Zinc which would play a substantial role in the defense mechanism of the plant. 

scholarly journals Pengaruh Waktu Steam Blanching dan Suhu Pengeringan terhadap Karakteristik Kimia serta Sensori Teh Daun Bambu Tabah (Gigantochloa nigrociliata BUSE-KURZ)

2019 ◽  
Vol 8 (2) ◽  
pp. 271
Author(s):  
I Nyoman Cahyadi Purnama ◽  
Pande Ketut Diah Kencana ◽  
I Made Supartha Utama
Keyword(s):  
Water Content ◽  
Ph Value ◽  
Raw Materials ◽  
Acid Value ◽  
Total Phenol ◽  
Total Phenol Content ◽  
Total Acid ◽  
Drying Temperature ◽  
Bamboo Leaves ◽  
Randomized Design

Bambu " tabah " adalah salah satu varietas bambu yang hanya ditemukan di pulau Bali . " Tabah " daun bambu memiliki potensi untuk dikembangkan sebagai bahan baku untuk membuat teh yang dapat menghasilkan minuman dengan berbagai manfaat. Jika dimanfaatkan secara optimal, daun bambu " tabah " dapat diolah sebagai produk yang akan memberikan keuntungan. Penelitian ini bertujuan untuk mengetahui pengaruh proses blanching dan pengeringan uap terhadap aktivitas kadar air, pH, asam total, fenol total, dan teh daun bambu " tabah " organoleptik . " Tabah "Daun bambu diperlakukan dengan waktu blanching uap dengan variasi waktu, yaitu selama 10 menit, 15 menit dan 20 menit. Setelah steam blanching, daun bambu" tabah "dikeringkan menggunakan oven dengan variasi suhu pengeringan 50 ° C, 60 ° C, dan 70 ° C. Metode penelitian yang digunakan adalah metode eksperimen dengan pola faktorial Rancangan Acak Lengkap (RAL) yang terdiri dari dua faktor dan diulang tiga kali. Faktor pertama adalah waktu blansing uap dan faktor kedua adalah suhu pengeringan.Hasil menunjukkan bahwa kombinasi terbaik dari perawatan berdasarkan penerimaan keseluruhan tes hedonis yang dihasilkan pada " tabah”Teh daun bambu adalah perlakuan waktu blansing uap 15 menit dengan suhu pengeringan 60 ° C (W2S2) yang menghasilkan 7,03% kadar air untuk kadar air SNI 8%, nilai pH 6,40, nilai asam total 0,94, total kadar fenol 54,95 , tes skor warna 4,47, tes skor aroma 4,87, tes skor rasa 4,60 dan tes keseluruhan penerimaan hedonis 4, 67.     Bamboo “tabah” is one of the bamboo variety of which finds only in Bali island. "Tabah" bamboo leaves have the potential to be developed as raw materials for making tea that can produce drinks with various benefits. If utilized optimally, "tabah" bamboo leaves can be processed as a product that will provide an advantage. This study aims to determine the effect of steam blanching and drying process on the activity of water content, pH, total acid, total phenol, and organoleptic " tabah" bamboo leaf tea. "Tabah" bamboo leaves are treated with steam blanching time with a variation of time, namely for 10 minutes, 15 minutes and 20 minutes. After steam blanching, the "tabah" bamboo leaves are dried using an oven with variations in the drying temperature of 50 ° C, 60 ° C and 70 ° C. The research method used was an experimental method with a completely randomized design (CRD) factorial pattern consisting of two factors and repeated three times. The first factor is the steam blanching time and the second factor is the drying temperature. The results showed that the best combination of treatments based on the overall acceptance of hedonic tests produced on “tabah” bamboo leaf tea is the treatment of 15 minutes steam blanching time with a drying temperature of 60 ° C (W2S2) which produces 7.03% water content for SNI water content 8%, pH value 6.40, total acid value 0.94, total phenol content 54.95, color scoring test 4.47, aroma scoring test 4.87, taste scoring test 4.60 and overall acceptance hedonic test 4, 67.

scholarly journals SCREENING OF PHYTOCHEMICAL, ANTIOXIDANT ACTIVITY AND ANTI-BACTERIAL ACTIVITY OF MARINE SEAWEEDS

2019 ◽  
Vol 11 (1) ◽  
pp. 61
Author(s):  
Rajasekar T. ◽  
Mary Shamya A. ◽  
Jerrine Joseph
Keyword(s):  
Total Protein ◽  
Antimicrobial Agents ◽  
Antioxidant Activities ◽  
Standard Procedure ◽  
Brown Seaweed ◽  
Ethanol Extract ◽  
Total Phenol ◽  
Total Carbohydrate ◽  
Methanol Extracts ◽  
Phytochemical Constituents

Objective: Phytochemical is naturally present in the seaweeds which biologically play a significant role. The intention of this study was designed to screen the phytochemical constituents and antimicrobial potential of selected seaweed collected from Rameshwaram and Tuticorin Southern coast of India.Methods: The present study investigated the presence of phytochemical constituents and also total phenol, total carbohydrate and total protein quantity of the brown seaweed. Dictyopteris delicatula, Padina gymnospora, Acanthophora spicifera, Portieria hornemannii and Ulva faciata were extracted with solvents having different polarities like methanol, ethanol, chloroform and water and screened for the phytochemical constituents, total phenol, total carbohydrate, total protein and DPPH with standard procedure. The antibacterial activities of the seaweeds were examined by agar well diffusion method.Results: Among the five seaweeds, U. faciata showed the maximum number of active constituents in the methanol extract likewise P. gymnospora was found to have a number of diligent compounds in ethanol extract. A. spicifera showed minimum compounds in ethanol as well as chloroform extract. Moreover A. spicifera, P. hornemannii have shown the superior quantity of protein and carbohydrate when compared to other species. The scavenging activity of methanol extracts at 5 mg/ml concentration P. hornemannii shows 18.2% and A. spicifera possess 17.1%. In the antibacterial activity, methanol extracts of all the seaweed showed a potential inhibitory activity against B. cereus and P. aeruginosa compared to other pathogens.Conclusion: The crude extract of seaweed manifest preferable antimicrobial and antioxidant activities, hence in the future, it would be good if it is further taken for treatment of human diseases or as new antimicrobial agents to replace synthetic antimicrobial agents.

scholarly journals Global Diversification Dynamics Since the Jurassic: Low Dispersal and Habitat-Dependent Evolution Explain Hotspots of Diversity and Shell Disparity in River Snails (Viviparidae)

2020 ◽  
Vol 69 (5) ◽  
pp. 944-961 ◽  
Author(s):  
Björn Stelbrink ◽  
Romy Richter ◽  
Frank Köhler ◽  
Frank Riedel ◽  
Ellen E Strong ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Morphological Diversity ◽  
Global Scale ◽  
Shell Morphology ◽  
Dominant Group ◽  
Data Set ◽  
Worldwide Distribution ◽  
Modern Species ◽  
High Transition ◽  
The Rich

Abstract The Viviparidae, commonly known as River Snails, is a dominant group of freshwater snails with a nearly worldwide distribution that reaches its highest taxonomic and morphological diversity in Southeast Asia. The rich fossil record is indicative of a probable Middle Jurassic origin on the Laurasian supercontinent where the group started to diversify during the Cretaceous. However, it remains uncertain when and how the biodiversity hotspot in Southeast Asia was formed. Here, we used a comprehensive genetic data set containing both mitochondrial and nuclear markers and comprising species representing 24 out of 28 genera from throughout the range of the family. To reconstruct the spatiotemporal evolution of viviparids on a global scale, we reconstructed a fossil-calibrated phylogeny. We further assessed the roles of cladogenetic and anagenetic events in range evolution. Finally, we reconstructed the evolution of shell features by estimating ancestral character states to assess whether the appearance of sculptured shell morphologies was driven by major habitat shifts. The molecular phylogeny supports the monophyly of the three subfamilies, the Bellamyinae, Lioplacinae, and Viviparinae, but challenges the currently accepted genus-level classification in several cases. The almost global distribution of River Snails has been influenced both by comparatively ancient vicariance and more recent founder events. In Southeast Asia, Miocene dispersal was a main factor in shaping the modern species distributions. A recurrent theme across different viviparid taxa is that many species living in lentic waters exhibit sculptured shells, whereas only one strongly sculptured species is known from lotic environments. We show that such shell sculpture is habitat-dependent and indeed evolved several times independently in lentic River Snails. Considerably high transition rates between shell types in lentic habitats probably caused the co-occurrence of morphologically distinct shell types in several lakes. In contrast, directional evolution toward smooth shells in lotic habitats, as identified in the present analyses, explains why sculptured shells are rarely found in these habitats. However, the specific factors that promoted changes in shell morphology require further work. [biogeographical analyses; fossil-calibrated phylogeny; fossil-constrained analyses; Southeast Asia; stochastic character mapping.]

scholarly journals Mathematical model for Plant-Insect interaction with dynamic response to PAD4-BIK1 interaction and effect of BIK1 inhibition

2017 ◽  
Author(s):  
Sanjay ◽  
Sabahuddin Ahmad ◽  
M. I. Siddiqi ◽  
Khalid Raza
Keyword(s):  
Mathematical Model ◽  
Plant Defense ◽  
Defense Mechanism ◽  
Plant Biomass ◽  
Plant Quality ◽  
Predator Prey Model ◽  
Enhanced Production ◽  
Interaction System ◽  
Plant Defense Mechanism ◽  
Plant Insect Interaction

AbstractPlant-insect interaction system has been a widely studied model of the ecosystem. Attempts have long been made to understand the numerical behaviour of this counter system and make improvements in it from initial simple analogy based approach with predator-prey model to the recently developed mathematical interpretation of plant-insect interaction including concept of plant immune interventions Caughley and Lawton (1981). In our current work, we propose an improvement in the model, based on molecular interactions behind plant defense mechanism and it’s effect on the plant growth and insect herbivory. Motivated from an interaction network of plant biomolecules given by Louis and Shah (2014) and extending the model of Chattopadhyay, et al (2001), we propose here a mathematical model to show how plant insect interaction system is governed by the molecular components inside. Insect infestation mediated induction of Botrytis Induced Kinase-1 (BIK-1) protein causes inhibition of Phyto Alexin Deficient-4 (PAD4) protein. Lowered PAD4, being responsible for initiating plant defense mechanism, results in degraded plant immune potential and thus causes loss of plant quality. We adapt these interactions in our model to show how they influence the plant insect interaction system and also to reveal how silencing BIK-1 may aid in enhanced production of plant biomass by increasing plant immunity mediated by increase in PAD4 and associated antixenotic effects. We hypothesize the significance of BIK-1 inhibition which could result in the improvement of the plant quality. We explain the interaction system in BIK-1 inhibition using mathematical model. Further, we adopted the plethora of computational modeling and simulations techniques to identify the mechanisms of molecular inhibition.

scholarly journals Evolution of hyperossification expands skull diversity in frogs

2020 ◽  
Vol 117 (15) ◽  
pp. 8554-8562 ◽  
Author(s):  
Daniel J. Paluh ◽  
Edward L. Stanley ◽  
David C. Blackburn
Keyword(s):  
Defense Mechanism ◽  
Three Dimensional ◽  
Morphological Data ◽  
Shape Variation ◽  
Skull Shape ◽  
Worldwide Distribution ◽  
History Of ◽  
Wide Scale ◽  
Head Morphology ◽  
Specialized Diet

Frogs (Anura) are one of the most diverse vertebrate orders, comprising more than 7,000 species with a worldwide distribution and extensive ecological diversity. In contrast to other tetrapods, frogs have a highly derived body plan and simplified skull. In many lineages of anurans, increased mineralization has led to hyperossified skulls, but the function of this trait and its relationship with other aspects of head morphology are largely unexplored. Using three-dimensional morphological data from 158 species representing all frog families, we assessed wide-scale patterns of shape variation across all major lineages, reconstructed the evolutionary history of cranial hyperossification across the anuran phylogeny, and tested for relationships between ecology, skull shape, and hyperossification. Although many frogs share a conserved skull shape, several extreme forms have repeatedly evolved that commonly are associated with hyperossification, which has evolved independently more than 25 times. Variation in cranial shape is not explained by phylogenetic relatedness but is correlated with shifts in body size and ecology. The species with highly divergent, hyperossified skulls often have a specialized diet or a unique predator defense mechanism. Thus, the evolution of hyperossification has repeatedly facilitated the expansion of the head into multiple new shapes and functions.

scholarly journals Identification and activity of active compound of bamboo leaves (Bambusa vulgaris Schrad ex.J.C) ethanolic extract against diabetic ulcers gram-negative bacteria from diabetic ulcer’s patient

2021 ◽  
Vol 17 (1) ◽  
pp. 96-106
Author(s):  
Pratiwi Apridamayanti ◽  
Keyword(s):  
Antibacterial Activity ◽  
Ethanol Extract ◽  
Total Phenol ◽  
Total Flavonoid ◽  
Gram Negative ◽  
E Coli ◽  
Bamboo Leaves ◽  
Bambusa Vulgaris ◽  
Fish Index ◽  
Foam Index

Background: Bamboo leaves (Bambusa vulgaris Schrad ex.J.C) are plants that are known to have pharmacological activity, one of which is to have antibacterial activity. Diabetic Foot Ulcers (DFU) is one chronic complication of diabetes mellitus. DFU is open sores on the surface of the skin that can be accompanied by local tissue death. Infection that is not appropriately treated in patients can cause amputation. Improper use of antibiotics can cause resistance events. A resistance that occurs in Proteus mirabilis, Pseudomonas aeruginosa, and Escherichia coli in isolates from DFU patients encourages researchers to look for alternative antibiotics from natural resources. Objective: Determine the profile of secondary metabolites by thin-layer chromatography, foam index, total phenols, total flavonoids and the antibacterial activity of bamboo (B. vulgaris) through the antibacterial with clear zone value of bamboo leaf ethanol extract against bacteria E. coli, P. aeruginosa, and P. mirabilis. Method: Phenol, flavonoid, and triterpenoid test using TLC method. Saponin tests were carried out using foam index, fish index, and hemolytic index test methods. Total flavonoid testing using Chang method and total phenol method using the Follin Ciocalteau reagent then proceed using a spectrophotometer. Test the antibacterial activity using the agar diffusion method. Results: Chromatographic profile, phenol, flavonoid, and triterpenoid compounds were obtained; saponin index obtained foam index of 333; fish index of 200; and the hemolytic index of 1,111. The total phenol test was 16.052 ± 3.12 % and the total flavonoid was 2.42 ± 0.44 %. Antibacterial activity test obtained MIC values of 60 mg/ml for E. coli bacteria; 100 mg/ml for the bacterium P. aeruginosa; and 30 mg/ml of P. mirabilis. Conclusion: The content of secondary metabolites found in the ethanol extract of bamboo leaves were flavonoid, phenol, saponin and triterpenoids. Ethanol extract of bamboo leaves has a the potential to produce antibacterial activity against gram-negative pathogenic bacteria isolated from diabetic wound patients Keywords: Bambusa vulgaris Schrad ex.J.C, total phenol, total flavonoid, MIC

scholarly journals Identification of antibodies to Leptospira spp. in the spot-legged turtle (Rhinoclemmys punctularia) maintained in captivity

2019 ◽  
Vol 40 (6Supl3) ◽  
pp. 3763
Author(s):  
Katarine de Souza Rocha ◽  
Ianny Watuzy Monteiro Baia ◽  
Louysse Helene Monteiro ◽  
Juliana Maria Santos Miranda ◽  
Thamillys Rayssa Marques Monteiro ◽  
...  
Keyword(s):  
Animal Species ◽  
Botanical Garden ◽  
Wild Animal ◽  
Agglutination Test ◽  
Aquatic Environments ◽  
Serum Samples ◽  
Worldwide Distribution ◽  
Leptospira Spp ◽  
In Captivity ◽  
Water Tanks

Leptospirosis is a zoonosis of worldwide distribution in which the agent can infect several animal species and accidentally humans. In view of the limited number of studies on anti-Leptospira antibodies in wild animal species, especially those living in aquatic environments, we sought in this study to investigate the presence of these antibodies in the spot-legged turtle (Rhinoclemmys punctularia) maintained in captivity in the Rodrigues Alves Botanical Garden–Amazon Zoobotanical Park, located in Belém, Pará State, Brazil. Serum samples were collected from 31 turtles, and identification of anti-Leptospira antibodies was performed using the microscopic agglutination test, using a collection of 31 live antigens which represent 19 serogroups of Leptospira. Among the analyzed samples, 54.83% (17/31) were observed to be reactive, and co-agglutination was detected in a further six samples which were not accounted for in the frequency of serogroups. The most frequently detected serogroups were Tarassovi 72.72% (8/11), Celledoni 18.18% (2/11), and Pomona 9.09% (1/11)], with titers ranging from 200 to 400, being this the first study to report infection of these serogroups in this species of chelonios. The animals were kept in water tanks, which probably favored the transport of the agent and allowed its transmission to the spot-legged turtle. We thus confirmed presence of anti-Leptospira antibodies in chelonians maintained in the Rodrigues Alves Botanical Garden.

scholarly journals Fruit growth and proximate composition of deshi (Diospyros peregrina) and bilati gab (D. discolor)

2016 ◽  
Vol 12 (2) ◽  
pp. 261-266
Author(s):  
MM Hasan ◽  
MSA Fakir ◽  
MM Rahman ◽  
S Naznin
Keyword(s):  
Proximate Composition ◽  
Growth Parameters ◽  
Fruit Size ◽  
Dry Weight ◽  
Botanical Garden ◽  
Morphological Characters ◽  
Fruit Weight ◽  
Nutritional Composition ◽  
Fruit Growth ◽  
Total Carbohydrate

Fruit (berry) growth, maturity and nutritional composition of deshi (Diospyros peregrina Gurke) and bilati Gab (D. discolor Gurke) were investigated at the Botanical Garden of Bangladesh Agricultural University, Mymensingh (24o26' and 24054' N and 90015' and 90030' E) between April and August, 2011. Flowers were tagged at first opening (days after flowering, DAF) and fruit growth was investigated up to maturity. Fruit size (length and diameter), individual fruit weight, AGR and proximate composition of matured fruits were investigated. Morphological and growth parameters were recorded at 7-days interval up to 63 DAF in deshi and 85 DAF in bilati gab. All the morphological characters of fruits were gradually increased with increasing DAF and followed sigmoid pattern. The length and diameter of the berry became 5.80 and 4.61 cm, respectively at 63 DAF in deshi gab, and 9.13 and 7.62 cm, respectively at 85 DAF in bilati gab. The fresh and dry weights of berries were also maximum at 63 DAF in deshi and at 85 DAF in bilati gab. The maximum dry weight of seed i.e. PM in deshi gab attained at 56 DAF and that of bilati gab at 83 DAF. The proximate composition of matured berries of deshi and bilati gab at PM showed little variation between the species and hence, average crude protein, crude fat, ash and total carbohydrate was 5.35, 1.08, 3.74 and 67.47%, respectively. It might be concluded that harvest maturity attained around two months after flowering in deshi gab with yellowish green colour on fruit coat and three months from flowering in bilati gab when fruits turn into deep red colour with average fruit fresh weight of 60 g and 220 g, respectively.J. Bangladesh Agril. Univ. 12(2): 261-266, December 2014

A rapid method for the direct identification of paramyxovirus in canine CSF by ultracentrifugation and negative staining as a rule out for distemper

1990 ◽  
Vol 48 (3) ◽  
pp. 594-595
Author(s):  
W.L. Steffens ◽  
M.B. Ard ◽  
C.E. Greene ◽  
A. Jaggy
Keyword(s):  
Subacute Sclerosing Panencephalitis ◽  
Clinical Signs ◽  
Viral Disease ◽  
Etiologic Agent ◽  
Mucosal Inflammation ◽  
Worldwide Distribution ◽  
Negative Stain ◽  
Viral Particles ◽  
Systemic Manifestations ◽  
Rule Out

Canine distemper is a multisystemic contagious viral disease having a worldwide distribution, a high mortality rate, and significant central neurologic system (CNS) complications. In its systemic manifestations, it is often presumptively diagnosed on the basis of clinical signs and history. Few definitive antemortem diagnostic tests exist, and most are limited to the detection of viral antigen by immunofluorescence techniques on tissues or cytologic specimens or high immunoglobulin levels in CSF (cerebrospinal fluid). Diagnosis of CNS distemper is often unreliable due to the relatively low cell count in CSF (<50 cells/μl) and the binding of blocking immunoglobulins in CSF to cell surfaces. A more reliable and definitive test might be possible utilizing direct morphologic detection of the etiologic agent. Distemper is the canine equivalent of human measles, in that both involve a closely related member of the Paramyxoviridae, both produce mucosal inflammation, and may produce CNS complications. In humans, diagnosis of measles-induced subacute sclerosing panencephalitis is through negative stain identification of whole or incomplete viral particles in patient CSF.

Activation of cytochrome c to a peroxidase compound I-type intermediate by H2O2: relevance to redox signalling in apoptosis

2004 ◽  
Vol 71 ◽  
pp. 97-106 ◽  
Author(s):  
Mark Burkitt ◽  
Clare Jones ◽  
Andrew Lawrence ◽  
Peter Wardman
Keyword(s):  
Cytochrome C ◽  
Hydroxyl Radical ◽  
Redox Regulation ◽  
Chemotherapeutic Agents ◽  
Tyrosyl Radical ◽  
Compound I ◽  
Definitive Evidence ◽  
Enhanced Production ◽  
Physico Chemical

The release of cytochrome c from mitochondria during apoptosis results in the enhanced production of superoxide radicals, which are converted to H2O2 by Mn-superoxide dismutase. We have been concerned with the role of cytochrome c/H2O2 in the induction of oxidative stress during apoptosis. Our initial studies showed that cytochrome c is a potent catalyst of 2′,7′-dichlorofluorescin oxidation, thereby explaining the increased rate of production of the fluorophore 2′,7′-dichlorofluorescein in apoptotic cells. Although it has been speculated that the oxidizing species may be a ferryl-haem intermediate, no definitive evidence for the formation of such a species has been reported. Alternatively, it is possible that the hydroxyl radical may be generated, as seen in the reaction of certain iron chelates with H2O2. By examining the effects of radical scavengers on 2′,7′-dichlorofluorescin oxidation by cytochrome c/H2O2, together with complementary EPR studies, we have demonstrated that the hydroxyl radical is not generated. Our findings point, instead, to the formation of a peroxidase compound I species, with one oxidizing equivalent present as an oxo-ferryl haem intermediate and the other as the tyrosyl radical identified by Barr and colleagues [Barr, Gunther, Deterding, Tomer and Mason (1996) J. Biol. Chem. 271, 15498-15503]. Studies with spin traps indicated that the oxo-ferryl haem is the active oxidant. These findings provide a physico-chemical basis for the redox changes that occur during apoptosis. Excessive changes (possibly catalysed by cytochrome c) may have implications for the redox regulation of cell death, including the sensitivity of tumour cells to chemotherapeutic agents.

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