Diagnosis of a neonatal ophthalmic discharge, Ophthalmia neonatorum, in the molecular age: investigation for a correct therapy.

An early double case of acute Ophthalmia neonatorum in 3-day-old twins is reported. Culture of eye swabs showed a wide bacterial polymorphism, in which common bacteria, such as Klebsiella pneumoniae, Streptococcus pneumoniae, Corynebacterium ulcerans and other Enterobacteriaceae, coexisted with atypical Mycoplasmataceae and Chlamydiaceae from resident cervical-vaginal maternal microbiota. The neonates were in an apparently healthy state, but showed red eyes with abundant greenish-yellow secretion, mild chemosis and lid edema. The maternal cervical-vaginal ecosystem resulted differently positive to the same common cultivable, atypical bacteria culturally and molecularly determined. This suggested a direct maternal-foetal transmission or a further foetal contamination before birth. An extended culture analysis for common bacteria to atypical ones was decisive to describe the involvement of Mycoplasmas (M. hominis and U. urealyticum) within the scenario of the Ophthalmia neonatorum in a Caucasian couple. The introduction of a routine PCR molecular analysis for Chlamydiaceae and N. gonorrhoeae allowed to establish which of these were present at birth, and contributed to determine the correct laboratory diagnosis and to define an adequate therapeutic protocol obtaining a complete resolution after one year for culture and atypical bacteria controls. This study suggests to improve the quality of laboratory diagnosis as unavoidable support to a correct clinical diagnosis and therapy, in a standardized modality both for swabbing and scraping, to check the new-born microbial programming starting in uterus, overtaking the cultural age to the molecular age, and to revise the WHO guidelines of SAFE Strategy for trachoma eye disease, transforming it into SAFES Strategy where the S letter is the acronym of Sexual ecosystem and behavioural valuation/education.

Cytokine expression profile and blood parameter evaluation of patients undergoing cardiac surgery.

Cardiac surgery is accompanied by an important immune response that is poorly understood. This inflammatory response is caused by several stimuli: surgical trauma, cardiopulmonary bypass apparatus, aortic-cross clamping, reperfusion injury and hypothermia. The aim of the present study is to investigate the cytokine level profile involved in the inflammatory pathway of patients undergoing cardiac surgery. One hundred and two patients undergoing elective cardiac surgery utilizing cardiopulmonary bypass (CPB) apparatus were enrolled in the study. In the hematological and biochemical profiles investigated, we observed a significant increase of WBC and blood glucose concentration and a strong decrease of RBC, HB, HCT and PLT 24 h post-surgery compared to baseline and immediately after surgery groups. Furthermore, we found a modulation of cytokine levels mostly for IL-10 and an increase of IL-6, detected at 6 h post-surgery, IL-8 at 6 and 24 h, and TNFα only at 24 h post-surgery. In conclusion, these findings evidence a time course profile on cytokine levels and a balance between pro- and anti-inflammatory cytokine activation during and after cardiac surgery. In fact, IL-6 and IL-10, a pro- and an anti-inflammatory cytokine, respectively, increased immediately after surgery. The plasma level of TNF-α could be inhibited by the high concentration of IL-10 up to 6 h post-surgery. An IL-10 reduction at baseline level, after 24 h post-surgery, could explain a rise of TNF-α plasma concentration. On the other hand, considering the dual role of IL-6 on inflammation acting both as an activator of inflammatory cascade or an anti-inflammatory agent, the increased IL-6 levels 24 h after surgery could be related to the negative feedback action on TNFα activity.

Cytokine modulation in patients with idiopathic pulmonary fibrosis undergoing treatment with steroids, immunosuppressants, and IFN-γ 1b.

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease of unknown etiology and pathogenic mechanisms. From an etiopathogenic point of view, alveolar macrophages play a key role in accumulation of fibroblasts and deposition of collagen and extracellular matrix by releasing specific cytokines and inflammatory mediators. IPF seems to be also associated with circulating fibrocytes, which might be involved with an abnormal pulmonary vascular repair and remodeling. Based on its hypothesized pathologic mechanisms, anti-inflammatory, anti-fibrotic and immunosuppressive therapies are often used. For these reasons, Interferon-g (IFN-g) has been used to exploit its activity on macrophages and fibroblasts. The aim of this study was to investigate the response to corticosteroids and/or IFN-g 1b treatments based on pulmonary function tests and on inflammatory cytokine patterns of expression on bronchoalveolar lavage (BAL), at baseline and during and after the therapies. Unlike previous studies, we analyzed a period of therapy longer than 1 year. Our results demonstrated the effectiveness of IFN-γ in a group of IPF patients in whom the treatment was prolonged for over a year. These data suggest a positive role of IFN-γ; treatment in patients in the initial stage of the disease.

Enigmatic question of early reactive arthritis disclosed after researches of mycoplasmas, Chlamydia trachomatis and enteropathogens following the holistic vision of human being.

An HLA-B27 genetic profile patient is fully investigated by molecular analyses after an anamnestic assessment of multi-site ecosystems, following the holistic vision of human being.VDRL and Widal-Wright (WWR) resulted positive, showing at Wright’s reaction a title of 1:40. Of all the enzymatic activities measured, only the ALP enzymatic pool activities showed a low increasing value of 297 U/L. Of all later acute phase proteins, Only C3 c protein value (127 mg/dL) and fibrinogen (376 mg/dL) were altered. Cultural and molecular oropharyngeal ecosystem investigation resulted significantly positive to Mycoplasmas(Mhand Uu) and Chlamydia trachomatis(Ct) together with a spread of saprophytic flora. From an accurate anamnesis, several and severe uro-genital clinical symptomatology emerged from birth until the beginning of rheumatologic symptomatologies that were confirmed by oldest Mh, Uu and Ctsilent chronic infections between these ecosystems. The molecular HPV research was negative, while the Thin prep pap-test was indicative of vaginosis and cellular reactive changes associated with inflammation. Parasitological research resulted positive for presence of 5-7 newly-formed G. lambliacysts for microscopic field, while digestibility test was positive for presence of several free fatty acid crystals. The remarkable presence of indigested meat fibre and several mucous dense filaments were observed. The pH value was 6.5, while blood faecal test was positive. The values observed were: ferritin 12 microg/L (10-120), total iron-binding capacity (TIBC) 310 &mgr;g/dL (300+-20), unsaturated iron-binding capacity (UIBC) 286 microg/dL (200-220) and iron seric level 24 microg/dL (60-130). Faecal research highlighted a very scarce presence of E. coli, resulting in 102 UFC/g of stool. Of all enteroinvasive pathogens, researched by molecular analyses, only Yersinia spp. was positive. After several specific cycles of antibiotic and antinflammatory therapies, the patient improved its general health condition considerably and showed almost complete regression of aching inguinal lymph node inflammation. In a picture of a worsening inflammatory process, produced by pathogens like Mycoplasmas, chronic silent or low grade inflammation atypical agents, in young HLA-B27 positive patient, VDRL test resulted positive. This value represents the first non-specific unique spy to reveal the precocious immunological signal in order to register the beginning of early innate immune system decay, keeping in mind that mycoplasmal and chlamydial infections are the triggering of cancer in patients genetically susceptible.

Can latent synergism of intestinal pathogens be responsible for inflammaging process causing Reiter's syndrome in a young patient HLA-B27 infected by atypical pathogens? A holistic view and clinical biochemical reinterpretation.

A case of a genetically HLA-B27 patient fully investigated by molecular analyses, following a holistic vision and an anamnestic assessment of multi-site ecosystems is repeated. VDRL, Lupus anti-coagulant (LAC) and Widal-Wright (WWR), resulted positive. The antibodies (IgG/IgA anti-Ct) against chronic Chlamydia trachomatis inflammation were positive. In the context of all the enzymatic activities in reference range, the AMS and the ALP enzymatic activities showed an increasing trend and a time course augment depending respectively. Cultures, parasitological, digestibility tests and molecular analyses were then performed to investigate the different human ecosystems. Parasitological research and digestibility test were performed, resulting a latent chronic bowel inflammation, including certain enteroinvasive pathogens, such as, Salmonella, Shigella, Yersinia and Campylobacter (Enteric Pathogens Group, EPG) and Escherichia Coli pathogens (Escherichia Coli Pathogens Group, ECPG). The Salmonella typhi-DNA resulted positive, while 90% of the total microbic charge (TMC) was represented by C. freundi in culture analyses. Interpreting the VDRL positive test as early triggering of autoimmune disease, a few acute phase proteins as a pauci-symptomatic chronic phlogistic process, the amylase and alkaline phosphatase alterations as tissue markers of early intestinal inflammation, the Widal's reaction positivity together with the precocious clinical and faecal manifestations, this study suggests the prime triggering role of these atypical pathogens to cause a chronic low grade autoimmune response against the tissue/organ susceptible target, causing inflammaging phenomenon in young patient with chronic latent infection by Salmonella typhi, leading to Reiter's syndrome, in HLA-B27 positive patient.

NAD(P)H oxidase p22(phox) polymorphism and cardiovascular function in amateur runners.

AIM: NAD(P)H system represents the major source of superoxide production at cardiovascular (CV) level. It has several genetic variants: in particular, the C242T polymorphism of its p22(phox) subunit is associated with a different oxidase activity, being the T allele related to a lower superoxide production. Although several authors investigated the protective effect of T allele in CV diseases, only few data are available on its functional role in physiological conditions. The aim of our study was to investigate the relationship between the p22(phox) C242T polymorphism and CV function in amateur runners. METHODS: Seventy-three male amateur runners were screened for CYBA polymorphism. CV analysis was performed by echocardiographic-Doppler examination and by PulsePen tonometer assessment. RESULTS: The genetic subgroups (CC and CT/TT) did not differ for VM O(2max) and cardiac dimension. Nevertheless, T carriers (n = 40) were characterized by a more efficient myocardial contraction and left ventricular (LV) filling, as evidenced by significant higher values of the midwall fractional shortening, systolic excursion of the tricuspid annular plane and of early/late diastolic wave velocities ratio and by a lower E wave deceleration time. Pulse wave velocity and augmentation index, parameters related to the arterial stiffness, were higher in CC subjects compared with CT/TT also when the analysis was adjusted for weight and diastolic pressure. CONCLUSION: In amateur runners, CYBA variants may influence both systolic and diastolic function and arterial stiffness. We suppose that the lower oxidative activity that characterizes 242T subjects may positively influence the excitation-contraction and arterial-ventricular coupling mechanisms, thus leading to a more efficient CV function.

Jugulodigastric lymph node inflammation derived from chronic atypical oropharyngeal phlogosis recurring annually after flu virus vaccination: a holistic vision of a clinical case solved after chlamydicidal antibiotic therapy.

In this report, we evaluated the case history of a patient with longstanding chronic pharyngitis who had periodic clinical manifestation for three years after a flu vaccine administration, and after various treatments tried to resolve the chronic pharyngitis with unsuccessful antibiotic and anti-inflammatory therapies. The patient occasionally presented a slight ocular inflammation, while dysuria occurred after sexual activity. The search for common pathogens by use of pharyngeal swabs resulted only in Corynebacterium ulcerans growth. After this first result, we focused our investigations on ocular and uro-genital infections of Chlamydiaceae (Ct and Cp) and Mycoplasmataceae (Mh and Uu) families. We examined the patient?s pharynx using molecular and culture techniques from three different sites. Although several infectious agents, including viruses and bacteria, causing chronic pharyngitis are reported in the literature, these ocular and uro-genital pathogens are seldomly routinely investigated in the same patient in ORL. Furthermore, while episodes of chronic pharyngitis is one of the most common clinical manifestation in ENT patients, these atypical pharyngitis represent ever-increasing infections which must always be considered and researched by suitable instruments such as PCR. Only from the collection of detailed medical history and careful observations of clinical manifestation, indicative of an oral chronic pathologic phenomenon of low intensity initiated several years previously, starting with sudden outbreak and relapse like a bout of flu, we suggest to study these atypical infecting agents frequently localized in the urogenital human area, awhich would allow to highlight and to recognize these clinical cases that manifest themselves as chronic inflammation of jugulodigastric lymph nodes, remaining still unrecognized and rarely associated to chlamydial infection, confused with the response to flu vaccination. After several specific cycles of antibiotic therapy, the patient's health improved considerably and showed almost complete regression of jugulodigastric lymph node inflammation.

Ocular clinical pictures disclosed by PCR molecular diagnosis of Chlamydia trachomatis infection performed following the appropriate sampling modality in ocular ecosystem.

Four clinical cases regarding the correct diagnosis of early ocular Chlamydia trachomatis (Ct) inflammation, performed by two different modalities on the ocular ecosystem, are discussed. The present study was carried out in parallel using a cotton flock ocular swab and the scraping of upper lid conjunctiva. The ocular samplings were carried out by a first ocular swab from inner canthus and fornix, while the second by a conjunctival scraping from upper the conjunctiva of four patients. In the first case, by ocular swab, all samples resulted negative to Ct-DNA research by PCR, while the cultural analyses showed a growth of saprophytic and opportunist germs in all patients. No growth micetes resulted. On the contrary, in the second case, by conjunctival scraping, three of four samples were positive to Ct-DNA research. No fungal growth was observed, while only the 3rd patient, negative to Ct-DNA research, showed microbial growth. Our study, carried out with two different modalities of sampling on different areas of the same ecosystem, showed different results, demonstrating the importance of sampling accuracy for chlamydial research by molecular analysis in PCR, during the slight phase of inflammation. These initial data indicate that laboratory diagnosis by PCR for precocious Ct infection, not revealed clinically, could represent the first step for a correct diagnostic procedure, eliminating one of the critical points, allowing an accurate, effective and precocious antibiotic therapy. We hypothesize that only by following these correct procedures of sampling during the early phase of chlamydial inflammation, in the future, will it be possible to reduce a pejorative evolution of this worsening disease in people genetically susceptible, building a more efficacious Public Health program of prevention against chronic conjunctivitis and to favour a major prevention of trachoma in endemic areas.

Left ventricular noncompaction cardiomyopathy.

Isolated left ventricular noncompaction (ILVNC) is a congenital abnormality in the structure of ventricular tissue due to amorphogenetic defect during embryogenesis. This rare entity can be easily diagnosed by the characteristic appearance of prominent trabeculations and deep inter-trabecular spaces. Clinical manifestations of this disease include benign and malignant ventricular arrhythmia, congestive heart failure signs, cardio-embolic events (stroke), mitral and pulmonary valve incompetence, and reduced global ventricular systolic function. We present the case report of a 58-year-old man with ILVNC.

Carotenoids and asymptomatic carotid atherosclerosis.

High plasma concentrations of lycopene and beta-carotene have been associated with reduced prevalence of cardiovascular disease. The aim of this study is to compare plasma concentrations of these carotenoids in subjects with or without ultrasonic evidence of asymptomatic carotid atherosclerosis. One hundred and sixty-five subjects underwent physical examination and ultrasonic measurement of common carotid artery intima-media thickness. Analysis of variance and logistic regression methods were used to determine whether differences existed between participants with or without ultrasonic evidence of asymptomatic carotid atherosclerosis. Of the 165 participants, 80 exhibited evidence of carotid atherosclerosis (carotid intima-media thickness>0.8 mm), while 85 did not (carotid intima-media thickness>0.8 mm), while 85 did not (carotid intima-media thickness<0.8 mm). Participants with ultrasonic evidence of carotid atherosclerosis exhibited significantly greater body mass index, significantly higher serum concentrations of total cholesterol, LDL-associated cholesterol and triglycerides, and significantly higher plasma concentrations of uric acid, C-reactive protein and fibrinogen. In contrast, participants with ultrasonic evidence of carotid atherosclerosis exhibited significantly lower plasma concentrations of lycopene and beta-carotene. These results suggest that lycopene and beta-carotene may play important roles in delaying the development of the early asymptomatic stage of carotid atherosclerosis. Encouraging adequate intakes of antioxidant carotenoids may provide an important public health service.

Differential impact of acute bout of exercise on redox- and oxidative damage-related profiles between untrained subjects and amateur runners.

Despite the demonstrated exercise-induced increase in reactive oxygen species (ROS) production, growing epidemiological evidence indicates that habitual, moderate physical activity reduces the incidence of several oxidative stress-based diseases. This apparent paradox can be explained taking into account that ROS produced during repeated exercise bouts may act as mild stressors able to trigger physiological and biomolecular hormetic responses through a number of redox-sensitive transcription pathways. Unfortunately, much more limited information is available from general population-based research, which could better reflect the condition of common people interested in achieving and maintaining good fitness levels. The present work aimed at investigating whether and how exercise-related habits in non-professional regular runners (n=33) can affect the systemic anti-oxidative capacity, and the resting serum levels of typical lipid peroxidation-related by-products and oxidatively-damaged proteins, in comparison with untrained sedentary individuals (n=25). We also analyzed in both groups the redox response elicited by a modified Bruce-based maximal exercise test on the same parameters. Our findings indicated that long-term regular and moderate practice of aerobic physical activity can increase antioxidant defense systems, lower the resting protein oxidation processes and reduce the immediate up-regulation of lipid-targeting oxidative stress in response to an acute bout of exercise.

NAD(P)H oxidase and pro-inflammatory response during maximal exercise: role of C242T polymorphism of the P22PHOX subunit.

Intense exercise induces a pro-inflammatory status through a mechanism involving the NAD(P)H oxidase system. We focused our attention on p22phox, a subunit of the NAD(P)H oxidase, and on its allelic polymorphism C242T, which is known to affect the functional activity of the enzyme. We investigated whether the p22phox C242T variants exhibit systemic effects in healthy subjects by analyzing the proinflammatory and cardiocirculatory responses to physical exercise in endurance athletes. The group of study consisted of 97 long distance runners, 37 +/- 4.4 yrs of age, with similar training history. The subjects underwent a maximal stress test during which both inflammatory and cardiopulmonary parameters were monitored. Our results demonstrate that T allele deeply influences the neutrophil activation in response to intense exercise, since T carriers were characterized by significantly lower release of myeloperoxidase (MPO), a classical leukocyte derived pro-inflammatory cytokine. In addition, the presence of T allele was associated with a higher cardiopulmonary efficiency as evidenced by a significantly lower Heart Rate (HR) at the peak of exercise and, when a dominant model was assumed, by a higher maximal oxygen uptake (VO2 max). On the other hand, no effects of 242T mutation on the plasmatic total antioxidant capacity (TAC) and on the cortisol responses to the physical exercise were detected. In conclusion, our data support a systemic role for p22phox C242T polymorphism that, modifying the intensity of the inflammatory response, can influence the cardiovascular adaptations elicited by aerobic training. These results contribute to support the hypothesis of a systemic effect for the C242T polymorphism and of its possible functional rebound in healthy subjects.

Circulating plasma antioxidants, inflammatory markers and asymptomatic carotid atherosclerosis in end-stage renal disease patients: a case control study.

Few studies have been conducted on the relationship between antioxidant plasma vitamin concentrations, inflammatory markers and carotid atherosclerosis with inconclusive results in endstage renal disease (ESRD) patients. A case-control study was performed to investigate the relationship between plasma antioxidant concentrations, inflammatory markers, and carotid intima-media thickness (CIMT) in healthy subjects and in patients undergoing hemodialysis (HD). We enrolled 40 subjects (20 healthy, 20 with ESRD) asymptomatic for carotid atherosclerosis. After carotid ultrasound investigation (CUI), medical history data, physical examination, venous blood samples were collected. These were analyzed for concentrations of antioxidant vitamins (A, E), carotenoids (lycopene, beta-carotene), inflammatory markers (C-reactive protein, fibrinogen), and lipid profile. Low concentrations of vitamin A, vitamin E, lycopene, and beta-carotene were significantly associated with carotid atherosclerosis in patients with ESRD (p less than 0.001). In addition, high concentration of low density lipoprotein cholesterol and total cholesterol (p less than 0.01), C-reactive protein and fibrinogen (p less than 0.001) were also associated with carotid atherosclerosis, while other laboratory parameters considered (high density lipoprotein cholesterol and triglycerides) were not significantly associated with carotid atherosclerosis. A regular intake of foods rich in antioxidant vitamins with low fat concentrations may slow the progression of atherosclerotic process in this group of patients.

Glutathione S-transferase, similar to sigma class, from skin secretions of Xenopus laevis.

Using glutathione affinity chromatography followed by isoelectrofocusing, we purified from the skin secretion of Xenopus laevis an isoenzyme of glutathione S-transferase with an apparent subunit molecular mass of 22.5 kDa and an isoelectric point at pH 5.1. Its N-terminal amino acid sequence was highly similar to that of the sigma class glutathione S-transferase, which previously was demonstrated to have a glutathione-dependent prostaglandin D2 synthase activity. Immunohistochemistry analysis revealed that the isoenzyme was located in the cytoplasm of granular gland cells.

Multiple unfolded states of glutathione transferase bbGSTP1-1 by guanidinium chloride.

Inactivation, dissociation, and unfolding of the homodimeric glutathione transferase (bbGSTP1-1) from Bufo bufo embryos were investigated at equilibrium, using guanidinium chloride (GdmCl) as denaturant. Protein transitions were monitored by enzyme activity, intrinsic fluorescence, far UV circular dichroism, glutaraldehyde cross-linking, and gel-filtration chromatography. At low denaturant concentrations (less than 0.5 M), reversible inactivation of the enzyme occurs. At denaturant concentrations between 0.5 and 1.5 M the enzyme progressively dissociates into structured monomers. At higher denaturant concentrations the monomers unfold completely. Refolding studies indicate that a total reactivation occurs only by starting from the enzyme denatured at concentrations below 0.5 M. The enzyme denatured at GdmCl concentrations higher than 0.5 M only partially refolds. Globally our results indicate that unfolding of the amphibian bbGSTP1-1 is a multistep process, i.e., inactivation of the structured dimer, dissociation into partially structured monomers, followed by complete unfolding.

Characterization of toad liver glutathione transferase.

The major form of glutathione transferase from the toad liver previously designed as Bufo bufo liver GST-7.6 (A. Aceto, B. Dragani, T. Bucciarelli, P. Sacchetta, F. Martini, S. Angelucci, F. Amicarelli, M. Miranda and C. Di Ilio, Biochem. J. 289 (1993) 417-422) has been characterized. According to its partial amino acid sequence, the toad enzyme may be included in the pi class GST and named bbGST P2-2. However, bbGST P2-2 appears to be immunologically, structurally and kinetically distinct from any other members of pi family, including bbGST P1-1, suggesting that it may constitute a subset of pi class GST. The data support the hypothesis that the transition from aquatic to terrestrial life causes a switch of the GST amphibian pattern promoting the expression of a GST form (bbGST P2-2) able to counteract, with higher efficiency, the toxic effects of reactive metabolites of oxidative metabolism and those of hydrophobic xenobiotics.

Purification and characterization of three Pi class glutathione transferase from monkey (Macaca fascicularis) placenta.

Three forms of glutathione transferase (GST) with an apparent isoelectric point of pH 4.65 (GST I), 4.75 (GST II) and 4.9 (GST III) were resolved from the monkey (Macaca fascicularis) placenta after GSH-affinity chromatography followed by chromatofocusing. Substrate specificity, immunological reactivity, as well as N-terminal aminoacid sequences indicate that the three enzymes belongs to the pi class of GST. Reverse phase HPLC analysis indicates that the three GST arise from the combination of two different subunits eluting respectively at 29.60 +/- 0.10 min and 32.43 +/- 0.13 min. GST I is an homodimer of the 29.60 +/- 0.10 min subunit, GST III is an homodimer of the 32.43 +/- 0.13 min subunit, whereas the GST II is an heterodimer of the 29.60 +/- 0.10 min and 32.43 +/- 0.13 min subunits. Our results strongly suggest that unlike human, multiple forms of pi class GST exist in monkey placenta.

Interaction of glutathione transferase P1-1 with captan and captafol.

Glutathione transferase (GST, EC 2.5.1.18) P1-1 was strongly inhibited by captan and captafol in a time- and concentration-dependent manner. The IC50 values for captan and captafol were 5.8 microM and 1.5 microM, respectively. Time-course inactivation of GSTP1-1 by two pesticides was prevented by 3 microM of hexyl-glutathione, but not by methylglutathione. The fact that the inactivated enzyme recovered all the 5,5'-dithiobis(2-nitrobenzoic acid) titrable thiol groups, with concomitant recovery of all its original activity after treatment with 100 microM dithiothreitol, suggested that captan and captafol were able to induce the formation of disulfide bonds. That the inactivation of GSTP1-1 by captan and captafol involves the formation of disulfide bonds between the four cysteinil groups of the enzymes was confirmed by the SDS-PAGE experiments on nondenaturant conditions. In fact, on SDS-PAGE, GSTP1-1 as well as the cys47ala, cys101ala, and cys47ala/cys101ala GSTP1-1 mutants treated with captan and captafol showed several extra bands, with apparent molecular masses higher and lower than the molecular mass of native GSTP1-1 (23.5 kDa), indicating that both intra- and inter-subunit disulfide bonds were formed. These extra bands returned to the native 23.5 kDa band with concomitant restoration of activity when treated with dithiothreitol.

Alteration of glutathione transferase subunits composition in the liver of young and aged rats submitted to hypoxic and hyperoxic conditions.

In the present work, we have studied glutathione transferase (GST) activity and GST subunits distribution in the liver of young and aged rats kept under hypoxic or hyperoxic normobaric conditions as model of oxidative stress. A significant decrease of GST activity was detected in young hypoxic rat liver, whereas a significant increase occurred in aged hypoxic liver. No significant alteration of activity was obtained in both young and aged rat livers subjected to hyperoxic treatment. Substrate specificity measurements, SDS/PAGE analysis and reverse-phase HPLC, of GSH-affinity purified fractions were used to study the changes in the GST subunits pattern occurring in the liver of rat as a consequence of hypoxic and hyperoxic treatment. The results demonstrate that young and aged rat liver has a different constitutive GST subunit pattern which are markedly and differentially altered in hypoxia or hyperoxia. The hyperoxic treatment caused an increase of GST subunit 3 in aged, but not in young liver. In aged liver, both the hypoxic and hyperoxic treatment produced a decrease of GST subunit 4. After hypoxic treatment GST subunit 3 significantly increased in both young and aged liver. GST subunit 1a increased in both young and adult liver after hyperoxia. Following hypoxia a decrease of subunit 1a was seen in both young and aged liver. After hypoxic treatment, subunit 6 doubled in young, but not in aged, livers. It was concluded that the alterations in GST subunit expression occurring in the liver as a consequence of hypoxic or hyperoxic treatment respond to the necessity of a better protection of liver against the products of oxidative metabolism.