Effect of spontaneous exercise on antioxidant capacity in rat muscles determined by electron spin resonance

AIMS

The effect of physical activity on antioxidant capacity in muscle remains unknown. This study investigated the effect of spontaneous exercise on antioxidant capacity in rat muscles determined by electron spin resonance (ESR), which is a technique for the direct detection of free radicals.

METHODS

Ten-week-old male Wistar rats were housed individually in cages with a running wheel. Rats were classified as high activity (HA), middle activity (MA) or low activity group (LA), based on an assessment of running distance covered over a 23-week period. After 23 weeks of housing, soleus (Sol), plantaris (Pl), gastrocnemius [deep/surface portions (GasD/GasS)] and heart (Hrt) muscles were isolated, and scavenging activity against superoxide anions (O(2)(*-)) and hydroxyl radicals (HO(*)) was determined by ESR using a spin-trap chemical. The citrate synthase (CS) activity was used as a marker of mitochondrial oxidative phosphorylation capacity.

RESULTS

Among the parameters measured, only O(2)(*-) scavenging activity in GasD significantly correlated with the running distance. The highest scavenging activity was observed in Hrt of HA rats. The O(2)(*-) scavenging activity in Pl of MA rats was significantly higher than that of LA rats. The O(2)(*-) scavenging activity of Sol and GasS was not significantly different between the three groups. Furthermore, the HO(*) scavenging activity of any muscle specimens was similar among the three groups and did not correlate with running distance at all. CS activity did not significantly differ between the three groups.

CONCLUSION

These data suggest that O(2)(*-) scavenging activity in specific types of muscle tissues would increase especially in spontaneously active animals. However, HO(*) scavenging activity would not.

Crescentic glomerulonephritis associated with renal cell carcinoma after cancer immunotherapy

A 59 year-old woman showed rapidly progressive glomerulonephritis during immunotherapy for metastatic renal cell carcinoma. She received unilateral nephrectomy and cytotoxic T lymphocyte (CTL) therapy for the treatment of retroperitoneal lymph node metastasis of renal cell carcinoma. With CTL therapy, her retroperitoneal lymph node mass decreased in size. One year after the third round of CTL therapy, her serum creatinine was increased and massive proteinuria occurred. Her renal biopsy specimen revealed necrotizing and crescentic glomerulonephritis with immune complex deposition. Her retroperitoneal lymph node mass continued to decrease in size. Consequently, for the purpose of avoiding interfering with the CTL therapy, we performed double filtration plasmapheresis (DFPP) monotherapy for removal of immune complexes without using immunosuppressive drugs or prednisolone. After 24 sessions of DFPP, her serum IgG was reduced from 3,942 mg/dL to 2,400 mg/dL, and proteinuria (from 9.0 g/day to 0.9 g/day) and renal function (serum creatinine; from 5.6 mg/dL to 2.2 mg/dL) also improved. However, 3 months after the final DFPP, she expired due to perforation of the colon. The autopsy sample of the kidney showed that most of the glomeruli were obsolescent, but immunoglobulin depositions were reduced and necrotizing lesions were diminished. In the patients with RPGN associated with renal cell carcinoma, renal functional recovery has not been observed upon immunosuppressive treatment. Consequently, plasmapheresis is considered to be one of the effective and safe methods for patients with this association. We also discuss previous reports of RPGN associated with renal cell carcinoma, or RPGN after cancer immunotherapy.

Nutcracker syndrome associated with severe anemia and mild proteinuria

A 70-year-old man was referred to our hospital with the chief complaint of gross hematuria. Urinalysis revealed gross hematuria (3+, RBC 100/HPF or more) and mild proteinuria (3+, 1.8 g/day) with no urinary casts. Computed tomography of the abdomen showed compression of the left renal vein between the superior mesenteric artery and the aorta. Ultrasonography showed an increased flow velocity at the stenotic portion of the left renal vein. An aortography and selective left renal arteriography showed that there was no evidence of tumor vessels or arterial abnormalities in the arterial phase. However, the venous phase revealed a stenosis of the left renal vein just lateral to the aorta as well as a reflux of contrast material toward the left gonadal vein which was dilated. In addition, cystoscopy revealed left ureteral bleeding. Based on these findings, we made the diagnosis of gross hematuria caused by nutcracker syndrome (NCS). We concluded that the main cause of the anemia and proteinuria in our patient was leakage of blood and this is confirmed by the relationship of red blood cells to protein in the urine because we proved whole blood and plasma protein loss in the urine by calculation. Fourteen months after discharge, both the gross hematuria and proteinuria spontaneously disappeared. This case strongly suggested that the first therapy for hematuria and proteinuria with NCS should be observation.

Glomerular crescents predominantly express cadherin-catenin complex in pauci-immune-type crescentic glomerulonephritis

AIMS

To investigate the expression of the cadherin complex in human crescentic glomerulonephritis to elucidate the role of intercellular adherens junction molecules in crescent formation.

METHODS AND RESULTS

Immunostaining revealed cadherin complexes localized in Bowman's epithelial cells, but not in podocytes, of normal human glomeruli. Eight adult cases with myeloperoxidase anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA)-related (pauci-immune type) crescentic glomerulonephritis were examined on immunofluorescence microscopy with anti-pan cadherin, p120 catenin, and beta-catenin antibodies. The specimens provided six cellular crescents, 12 fibrocellular crescents, and four fibrotic crescents. Immunofluorescence was semiquantitatively estimated by the rate of the field of localization within the whole area of the crescent, according to the four-grade system [(-) - (++)]. All the tested molecules consisting of the cadherin complex were abundantly observed in cytokeratin-positive epithelial components in crescents, each with an equivalent area of localization. The expression of the cadherin complex was closely associated with that of cytokeratin and both diminished as the crescents developed from cellular to fibrotic.

CONCLUSIONS

The cadherin-catenin complex is a specific marker of Bowman's epithelial cells in human glomeruli. The cellular crescents in pauci-immune-type crescentic glomerulonephritis possess adherens junction molecules, indicating a principle parietal epithelial cell phenotype.

The antioxidant EPC-K1 ameliorates brain injury by inhibiting lipid peroxidation in a rat model of transient focal cerebral ischaemia

BACKGROUND

Cerebral ischaemia-reperfusion injury is associated with the generation of reactive oxygen species during the early phases of reoxygenation. EPC-K1, a phosphate diester of vitamins C and E, has been reported to possess potent hydroxyl radical scavenging activity. This study was performed to investigate the effectiveness of EPC-K1 in attenuating cerebral ischaemia-reperfusion injury in a rat model of transient focal cerebral ischaemia.

METHOD

We evaluated the efficacy of EPC-K1 by measuring the concentration of cerebral thiobarbituric acid reactive substances (TBARS), an indicator of the extent of lipid peroxidation by free radicals, and infarct size in rats subjected to one hour of cerebral ischaemia and 4, 24, or 72 hours of reperfusion.

FINDINGS

EPC-K1 significantly reduced both the cerebral TBARS level and the infarct size in a rat model of transient focal cerebral ischaemia. These results indicate that EPC-K1 administration during the early stages of reperfusion ameliorates ischaemic brain injury by inhibiting lipid peroxidation.

INTERPRETATION

This report is the first to describe the protective mechanism of EPC-K1 by measuring both the TBARS level and infarct size in a rat model of transient focal cerebral ischaemia, and may suggest a potential clinical approach for the treatment of ischaemic cerebrovascular disease.

A nonspectroscopic method to determine the photolytic decomposition pathways of 3-chloro-3-alkyldiazirine: carbene, diazo and rearrangement in excited state

C(60) acts as a mechanistic probe for the formation of carbene, diazo compound, and for the rearranged product via the excited state in the photolysis of 3-chloro-3-isopropyldiazirine and 3-chloro-3-chloromethyldiazirine. The carbene adds to C(60) to form methanofullerene, whereas the diazo compound adds to C(60) to form fulleroid. The olefin product arises as a result of the rearrangement in the excited state.

Mg@C72 MNDO/d evaluation of the isomeric composition

Temperature development of the relative stabilities of isomers of Mg@C72 (which has not yet been isolated) is computed using the recently introduced MNDO/d method. Four isomers originally considered for the Ca@C72 case are treated: one isolated-pentagon-rule (IPR) structure, two structures with a pair of adjacent pentagons, and one cage with a heptagon. The IPR structure comes as the lowest in MNDO/d potential energy, being rather closely followed by the two structures with a pentagon-pentagon pair. On the other hand, the structure with a heptagon is located too high in potential energy to be of any experimental significance. The entropy contributions are evaluated by the MNDO/d-based partition functions so that the relative concentrations can be treated accordingly. The computations suggest that if Mg@C72 is isolated, it should be a mixture of either two or three isomers. The prediction depends on temperature prehistory. If preparation takes place at temperatures of approximately 1000 K, two isomers should be produced. If temperatures are increased to approximately 2000 K, there will already be three isomers with significant relative concentrations. The study supplies a further interesting example of the profound role of enthalpy-entropy interplay in stabilities of isomeric fullerenic structures.

Synthesis, structure, electrochemistry, and spectroelectrochemistry of hypervalent phosphorus(V) octaethylporphyrins and theoretical analysis of the nature of the PO bond in P(OEP)(CH(2)CH(3))(O)

A variety of phosphorus(V) octaethylporphyrin derivatives of the type [P(OEP)(X)(Y)](+)Z(-) (OEP: octaethylporphyrin) (X = CH(3), CH(2)CH(3), C(6)H(5), F; Y = CH(3), CH(2)CH(3), OH, OCH(3), OCH(2)CH(3), On-Pr, Oi-Pr, Osec-Bu, NHBu, NEt(2), Cl, F, O(-); Z = ClO(4), PF(6)) were prepared. X-ray crystallographic analysis of eleven compounds reveals that the degree of ruffling of the porphyrin core becomes greater and the average P-N bond distance becomes shorter as the axial ligands become more electronegative. Therefore, the electronic effect of the axial substituents plays a major role in determining the degree of ruffling although the steric effect of the substituents plays some role. A comparison of the (1)H NMR chemical shifts for the series of [P(OEP)(CH(2)CH(3))(Y)](+)Z(-) complexes with those of the corresponding arsenic porphyrins, which possess a planar core, indicates a much smaller ring current effect of the porphyrin core in the severely ruffled phosphorus porphyrins. The electrochemistry, spectroelectrochemistry and ESR spectroscopy of the singly reduced compounds are also discussed. The OH protons of [P(OEP)(X)(OH)](+) are acidic enough to generate P(OEP)(X)(O) by treatment with aq dilute NaOH. X-ray analysis of P(OEP)(CH(2)CH(3))(O) reveals that the PO bond length is very short (1.475(7) A) and is comparable to that in triphenylphosphine oxide (1.483 A). The features of the quite unique hexacoordinate hypervalent compounds are investigated by density functional calculation of a model (Por)P(CH(2)CH(3))(O) and (Por)P(F)(O) (Por: unsubstituted porphyrin).

Antimicrobial susceptibility of Staphylococcus intermedius isolated from healthy and diseased dogs

A total of 90 strains of Staphylococcus intermedius isolated from dogs were examined for antimicrobial susceptibility. There were no significant differences in the distribution patterns of MICs between strains from 1982 to 1985 and those from 1999, and between strains from healthy dogs and those from diseased dogs. All of the strains were susceptible to ABPC, DMPPC, CEX, TDM, ERFX, BFLX, and FF at concentrations of 0.05 to 6.25 microg/ml. The MICs of OTC, KM, EM, AIV-TS, and LCM were distributed in a broad range of 0.1 to >100 microg/ml, indicating the existence of resistant as well as susceptible populations of S. intermedius. Thirty-three strains (36.7%) were resistant to one or more anitmicrobial agents such as OTC (n=32), KM (n=9), EM (n=7), AIV-TS (n=7), and LCM (n=7).

Role of nitric oxide in the synthesis of guanidinosuccinic acid, an activator of the N-methyl-D-aspartate receptor

BACKGROUND

We propose that reactive oxygen and argininosuccinic acid (ASA) form guanidinosuccinic acid (GSA). An alternative to this hypothesis is the so-called guanidine cycle, which consists of a series of hydroxyurea derivatives that serve as intermediates in a pathway leading from urea to GSA. We compare the role of the guanidine cycle to that of nitric oxide (NO) in the synthesis of GSA.

METHODS

The members of the guanidine cycle (hydroxyurea, hydroxylamine plus homoserine, L-canaline, and L-canavanine) were incubated with isolated rat hepatocytes. The known NO donors, NOR-2, NOC-7, and SIN-1, were incubated with ASA in vitro. Ornithine, arginine, or citrulline, which increase arginine, a precursor of NO, were incubated with isolated rat hepatocytes. GSA was determined by high-performance liquid chromatography.

RESULTS

None of guanidine cycle members except for urea formed GSA. SIN-1, which generates superoxide and NO formed GSA, but other simple NO donors, did not. Both carboxy-PTIO, a scavenger of NO, and dimethyl sulfoxide, a hydroxyl radical scavenger, completely inhibited GSA synthesis by SIN-1. GSA formation by SIN-1 reached a maximum at 0.5 mmol/L and decreased at higher concentrations. GSA synthesis, stimulated by urea in isolated hepatocytes, was inhibited by ornithine, arginine, or citrulline with ammonia, but not by ornithine without ammonia, where arginine production is limited.

CONCLUSION

GSA is formed from ASA and the hydroxyl radical. When arginine increased in hepatocytes, GSA synthesis decreased. These data suggest that increased NO, which results from high concentrations of arginine, or SIN-1 scavenges the hydroxyl radical. This may explain the decreased GSA synthesis in inborn errors of the urea cycle where ASA is decreased, and also the diminished GSA excretion in arginemia.

Relatively benign clinical course in asymptomatic patients with brugada-type electrocardiogram without family history of sudden death

INTRODUCTION

The incidence of sudden death or ventricular fibrillation (VF) in asymptomatic Brugada syndrome patients with a family history of sudden death is reported to be very high. However, there are few reports on the prognosis of asymptomatic Brugada syndrome patients without a family history of sudden death.

METHODS AND RESULTS

Eleven patients (all male; mean age 40.5 +/- 9.6 years, range 26 to 56) with asymptomatic Brugada-type ECG who had no family history of sudden death were evaluated. The degrees of ST segment elevation and conduction delay on signal-averaged ECG (SAECG) before and after pilsicainide were evaluated in all 11 patients. VF inducibility by ventricular electrical stimulation also was evaluated in 8 of 11 patients. Patients were followed for a period of 9 to 84 months (mean 42.5 +/- 21.6). The J point level was increased (V1: 0.19 +/- 0.09 mV to 0.36 +/- 0.23 mV; V2: 0.31 +/- 0.12 mV to 0.67 +/- 0.35 mV) by pilsicainide. Conduction delay was increased (total QRS: 112.2 +/- 6.3 msec to 131.7 +/- 6.3 msec; under 40 microV: 42.0 +/- 8.5 msec to 52.7 +/- 12.7 msec; last 40 msec: 17.4 +/- 5.9 microV to 10.4 +/- 6.1 microV) on SAECG by pilsicainide. VF was induced in only 1 of 8 patients. None of the patients had syncope or sudden death during a mean follow-up of 42.5 +/- 21.6 months.

CONCLUSION

This study suggests that asymptomatic patients with Brugada-type ECG who have no family history of sudden death have a relatively benign clinical course.

Hemodialysis does not influence the peroxidative state already present in uremia

Hemodialysis (HD) patients are exposed to high oxidative stress, however, the nature of this stress is still unclear. In this study, we employed a specific lipid peroxidative product, phosphatidylcholine hydroperoxide (PCOOH), and evaluated the peroxidative effect of end stage renal disease by measuring thiobarbituric acid reactive substances (TBARS) and PCOOH in both plasma and erythrocyte membrane. We also surveyed plasma TBARS and PCOOH before and after HD sessions thereby assessing oxidative stress by a single HD procedure. The plasma TBARS level of healthy controls was 2.9 +/- 0.4 nmol/ml. Those of HD patients before and after HD session were 5.1 +/- 1.4 and 3.1 +/- 0.5 nmol/ml, respectively, and the pre-HD plasma TBARS levels were significantly higher than those of controls and after HD. The plasma PCOOH concentration of patients before HD was 119.7 +/- 58.4 pmol/ml and was significantly higher than that of controls which was 88.6 +/- 14.3 pmol/ml. After HD, the plasma PCOOH level decreased to 103.2 +/- 36.0 pmol/ml, which was still significantly higher than that of controls. In erythrocytes, the PCOOH level of patients was 259.3 +/- 105.4 nmol/g RBC and was significantly higher than that of controls with 88.6 +/- 32.0 nmol/g RBC. Analyzed with respect to the cause of renal disease, the polycystic kidney disease patients showed significantly lower plasma PCOOH levels than the others. These results suggest that there is an increase of lipid peroxidation in both plasma and erythrocytes of HD patients, though this oxidative stress was not brought about by HD.

Biosynthesis of methylguanidine in the hepatic peroxisomes and the effect of the induction of peroxisomal enzymes by clofibrate

A state of peroxidation is one of the factors contributing to uremia. For example, we have reported that certain species of reactive oxygen, particularly the hydroxyl radical, play an important role in the biosynthesis of methylguanidine which contributes to toxicity in patients with uremia. However, it is uncertain which enzymes are involved in the synthesis of methylguanidine from creatinine. In this study, we attempt to show methylguanidine synthesis in the presence of peroxisomal enzymes that catalyze the beta-oxidation of fatty acids. In addition, we investigate the effect of clofibrate, which induces peroxisomal enzymes or glutathione peroxidase activity, on methylguanidine synthesis in the peroxisomal fraction. Male Wistar rats were fed with the chow containing 0.5% clofibrate to induce peroxisomal enzymes and control rats were fed with ordinary laboratory chow. Peroxisomal fractions were obtained from liver homogenates by centrifugation, and incubated with creatinine in 0.1 M potassium phosphate buffer pH 7.4 at 37 degrees C. Results show that methylguanidine is synthesized from creatinine concomitant with the synthesis of hydrogen peroxide from endogenous substrates in the peroxisomal fraction. This methylguanidine synthesis is inhibited by the addition of dimethylsulfoxide, glutathione, or sodium azide (p < 0.01). The rate of methylguanidine synthesis in clofibrate-treated rats was significantly less than that in control rats (p < 0.02). These results suggest that methylguanidine is synthesized in the peroxisomal fraction, and reactive oxygen species which are generated through this enzymatic reaction, participate in methylguanidine synthesis. Moreover, the induction of a scavenger system, especially glutathione peroxidase takes precedent over the generation of reactive oxygen species in peroxisomes treated with clofibrate.

Changes in cochlear electrical stimulation induced Fos expression in the rat inferior colliculus following deafness

Fos immunoreactive (IR) staining was used to examine changes in excitatory neuronal activity in the rat inferior colliculus (IC) between normal hearing and 21 day deaf rats evoked by basal or apical monopolar cochlear electrical stimulation. The location of evoked Fos IR neurons was consistent with expected tonotopic areas. The number of Fos IR cells increased as stimulation intensity increased in both normal and 21 day deaf animals. Stimulation at 1. 5x threshold evoked fewer Fos IR cells in 21 day deafened animals compared to normal hearing animals. At 5x and above, however, significantly increased numbers of Fos IR neurons (in a larger grouping) were evoked in 21 day deafened animals compared to normal hearing animals. Another group of animals had 7 days of deafness followed by 14 days of chronic basal cochlear electrical stimulation. In this group basal monopolar stimulation at 5x evoked not only a greater number of Fos IR neurons, compared to normal hearing animals, but the location of their grouping was slightly shifted to a more dorso-lateral region in the contralateral IC, compared to the normal hearing and 21 day deaf groups. These observations indicate that both deafness and chronic electrical stimulation may alter central auditory processing.

Cytokines and T-cell responses in superantigen-related glomerulonephritis following methicillin-resistant Staphylococcus aureus infection

BACKGROUND

We have previously reported that 10 patients who developed glomerulonephritis (GN) in association with methicillin-resistant Staphylococcus aureus (MRSA) infection showed a marked increase in DR+CD4+ and DR+CD8+ subsets of T cells and in T cells expressing several T-cell receptor (TCR) V beta+cells, perhaps representing V beta-specific T-cell activation by MRSA-derived superantigens (Kidney Int 1995; 47: 207-216). In this study we examine cytokine levels, T-lymphocyte subsets, natural killer NK cells, memory T cells, and the expression of IL-2 receptors in order to better understand the role of bacterial superantigens and cytokines in the pathogenesis of MRSA-associated GN.

METHODS

Twenty-two patients with MRSA infection who later developed GN caused by staphylococcal enterotoxin were evaluated immunologically in comparison with patients whose MRSA infection was not followed by GN (non-GN group) and normal individuals.

RESULTS

Among peripheral lymphocytes, the frequency of T cells expressing several TCR V betas, especially V beta 5-family TCR, was higher in the GN group than in both the non-GN group and the normal healthy control group. GN patients also showed increased serum levels of several cytokines, including tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), IL-2, IL-6, IL-8, and IL-10, which have been implicated in the onset of nephritis. Memory cells, and IL-2 receptors also were elevated in the GN group.

CONCLUSION

These results suggest that T cells activated by MRSA-derived staphylococcal enterotoxins and subsequent production of cytokines may play an important role in the pathogenesis of MRSA-associated GN.

Apolipoprotein E allele-dependent antioxidant activity in brains with Alzheimer's disease

Thiobarbituric acid-reactive substances (TBARS), an index of lipid peroxidation, were assayed in postmortem brain. Basal TBARS levels were increased and oxidative stimulation produced more TBARS in AD relative to control brains. In addition, apolipoprotein E isoforms showed differing antioxidant activities, with E2 > E3 > E4, suggesting that the lowest antioxidant activity of E4 could contribute to its association with AD.

Novel germline mutations in the PTEN tumour suppressor gene found in women with multiple cancers

Germline mutations in PTEN can predispose people to Cowden syndrome (CS) and Bannayan-Ruvalcaba-Riley (BRR) syndrome, rare, autosomal dominantly inherited neoplastic disorders. To determine whether germline mutations in PTEN contribute to genetic predisposition to multiple primary tumours within the general population, we conducted a nested case-control study, among 32 826 members of the prospective Nurses' Health Study cohort; cases were women with more than one primary tumour at different anatomical sites. We screened all nine exons of PTEN and flanking intronic splice sites for all 103 eligible cases using SSCP and sequencing. We observed two novel germline heterozygous missense mutations in exon 5 in five of the cases; three were V119L and two were V158L. Neither mutation was observed in 115 controls free of diagnosed cancer (p = 0.02). Both mutants showed partial tumour suppressor activity when compared to wild type PTEN when transfected into a PTEN null breast cancer cell line. The phenotype was cell line specific suggesting that genetic background affects growth suppression activity of the mutants. These data provide evidence that germline mutations in PTEN may be a more frequent predisposing factor for cancers in women than previously suggested.

Effects of methotrexate and cyclophosphamide on polyamine levels in various tissues of rats

The effects of methotrexate (MTX) and cyclophosphamide (CYP) on body weight, organ weight, and the concentration of putrescine, spermidine, and spermine in 14 different tissues were measured in rats that had been given these compounds for 5 consecutive days. These three polyamines in both the thymus and spleen of rats treated with MTX and CYP showed a statistically significant decrease. Further, putrescine in the seminal vesicles, kidney, liver, and small intestine of MTX-treated rats, and in the prostate, seminal vesicles, kidney, heart, liver, small intestine, and lung of CYP-treated rats, spermidine in the prostate, seminal vesicles, testis, thymus, spleen, kidney, heart, small intestine, and skeletal muscle of CYP-treated rats, and spermine in the prostate, seminal vesicles, kidney, heart, small intestine, and stomach of CYP-treated rats showed statistically significant decreases. Recognition of the significance of polyamine levels and attention to their response in anti-cancer drug therapy may have clinical implications.