Involvement of cytochrome P450 1A in sanguinarine detoxication

Sanguinarine (SA), a member of the benzo[c]phenanthridine alkaloids, is a potent anti-microbial agent with anti-inflammatory and anti-neoplastic properties. However, toxicity of the alkaloid severely limits its medical applications. Recent report by Williams et al. implicated rat hepatic cytochrome P450 (CYP) 1A2 as a likely modulator of SA toxicity. Indeed, the in vitro toxicity of SA in primary culture of rat hepatocytes and human hepatic cell line HepG2, demonstrated as lactate dehydrogenase leakage and metabolic capability (MTT assay), was diminished following induction of CYP1A by 2,3,7,8-tetrachlorodibenzo-p-dioxin, 3-methylcholanthrene, and beta-naphtoflavone. Using microsomes containing recombinant CYP1A1 or CYP1A2 we show that SA causes non-competitive inhibition of the former and competitive inhibition of the latter as assessed by ethoxyresorufin de-ethylation (EROD). In human hepatic microsomes SA exhibits competitive inhibition of EROD activity with apparent K(i) of 2 microM, a value identical to that observed for CYP1A2 inhibition in recombinant system. Pre-incubation of SA with human liver microsomes resulted in time-dependent, but not dose-dependent decline in EROD activity suggesting CYP1A2 inhibition is not mechanism based. SA also inhibits activity of NADPH:CYP reductase, an enzyme required for CYP activity, with IC(50) very similar to that observed for EROD inhibition. Tentative mechanism for CYP1A involvement in decreased in vitro SA toxicity is discussed.     

Chemoprotective effect of plant phenolics against anthracycline-induced toxicity on rat cardiomyocytes. Part I. Silymarin and its flavonolignans

Silymarin, an extract of fl avonolignans from the dried fruits of milk thistle (Silybum marianum L. Gaertneri) and its constituents silibinin, dehydrosilibinin, silychristin and silydianin were tested for protective effects on rat cardiomyocytes exposed to doxorubicin. Silymarin and individual fl avonolignans did not exert cytotoxicity in the range 25-100 micro m (incubation 9 h). Dehydrosilibinin was tested only at 25 micro m concentration due to its low solubility. All substances increased the cell ATP level. Silymarin and fl avonolignans displayed a dose-dependent cytoprotection against doxorubicin (100 micro m, incubation 8 h). The protective effects of silymarin, silibinin, dehydrosilibinin and silychristin were comparable to that of dexrasoxane, while silydianin exerted the best protective effect. The ability of silymarin complex and its components to protect cardiomyocytes against doxorubicin-induced oxidative stress is due mainly to their cell membrane stabilization effect, radical scavenging and iron chelating potency.     

Eyelid abscess as a presenting sign of occult sinusitis

PURPOSE: To describe 5 patients who presented with eyelid abscesses whose subsequent workup revealed occult sinusitis. METHODS: We reviewed the medical records of 5 patients who presented with eyelid abscess. Common presenting signs and symptoms were identified. Successful diagnosis and treatment was accomplished in each case. RESULTS: All patients were in good general health and did not appear to be systemically ill. Eyelid swelling was the chief presenting complaint of each patient. None of the patients complained of fevers or chills. Each patient had an upper eyelid abscess. Symptoms suggestive of sinusitis included purulent nasal discharge and headache. With appropriate radiologic studies, extensive occult sinusitis was identified in each case. Two patients demonstrated a small defect in the bone between the infected frontal sinus and the eyelid. All patients received intravenous antibiotics followed by oral antibiotics, incision and drainage of the abscess, and, after ENT consultation, functional endoscopic sinus surgery. All patients improved after treatment, and none had permanent visual loss. CONCLUSIONS: Clinical suspicion of sinusitis may be aroused with a thorough history and examination. Radiographic evaluation and prompt treatment of both the eyelid abscess and the sinusitis can result in good outcomes for such patients.     

The management of strabismus in adults--III. The effects on disability.

INTRODUCTION: This is the third article in a series on the various facets of the management of strabismus in adults. Here, we give a broad overview of the types and severity of disability and provide initial validation of an instrument (questionnaire) to assess these disability aspects. METHODS: After undergoing strabismus surgery, 101 patients from 6 centers completed a 6-item questionnaire in which they rated both the before-surgery and after-surgery severity of problems associated with their strabismus, ranging from specific health, daily functioning, social interaction, concerns about the future, and self-image to job-related difficulties. RESULTS: The before-surgery outcomes showed significant variation across the 6 types of problems (P < 0.001), with "specific health" and "daily tasks" yielding the highest problem rating. Patients with diplopia reported more severe problems with "daily tasks" (P = 0.004) and "concerns about the future" (P = 0.026) than patients without diplopia. Overall, all problem ratings declined after surgery (P < 0.001), but patients who were not successfully aligned were left with higher problem ratings on "specific health" (P = 0.005), "daily tasks" (P = 0.003), and "social interaction" (P = 0.024). CONCLUSIONS: The results indicate a wide range of disability aspects in adult patients with strabismus, with moderate differences between patients with or without diplopia. Improvements in disability after surgery, as reflected by these ratings, should be taken into account when assessing the health value of adult strabismus management.     

Oxidative stress and platelet function in multiple myeloma and renal insufficiency: clinical relations of different tests

Hemorrhagic tendency is frequent in uremic patients and is often associated with prolonged bleeding time and decreased platelet functions in vitro. Similarly, in multiple myeloma, platelet functions are affected, mainly by the inhibitory effect of paraprotein. We have studied patients with renal insufficiency and multiple myeloma to investigate the possible relation of oxidative stress to platelet functions, adhesion and aggregation activity. We observed diminished platelet aggregation response to collagen, ADP and thrombin receptor-activating peptide (TRAP) in both groups of patients as compared with normals. The adhesion of platelets to fibrin dimers was also diminished. Malondialdehyde concentration as a criterion of oxidative stress was significantly enhanced in both groups of patients together with increased concentrations of vitamins A and E. It seems to be possible that oxidative stress contributes to modification of adhesion proteins and fibrinogen and, thus, augments the observed inhibitory influence of vitamin E on platelet aggregation and adhesion. In conclusion, the concerted influence of both malondialdehyde and vitamins A and E can contribute to diminished platelet functions in renal insufficiency and augment the inhibitory influence of paraprotein on platelet functions in multiple myeloma.     

The role of cerebrospinal fluid hypocretin measurement in the diagnosis of narcolepsy and other hypersomnias

CONTEXT: Narcolepsy, a neurological disorder affecting 1 in 2000 individuals, is associated with HLA-DQB1*0602 and low cerebrospinal fluid (CSF) hypocretin (orexin) levels. OBJECTIVES: To delineate the spectrum of the hypocretin deficiency syndrome and to establish CSF hypocretin-1 measurements as a diagnostic tool for narcolepsy. DESIGN: Diagnosis, HLA-DQ, clinical data, the multiple sleep latency test (MSLT), and CSF hypocretin-1 were studied in a case series of patients with sleep disorders from 1999 to 2002. Signal detection analysis was used to determine the CSF hypocretin-1 levels best predictive for International Classification of Sleep Disorders (ICSD)-defined narcolepsy (blinded criterion standard). Clinical and demographic features were compared in narcoleptic subjects with and without low CSF hypocretin-1 levels. SETTING: Sleep disorder and neurology clinics in the United States and Europe, with biological testing performed at Stanford University, Stanford, Calif. PARTICIPANTS: There were 274 patients with narcolepsy; hypersomnia; obstructive sleep apnea; restless legs syndrome; insomnia; and atypical hypersomnia cases such as familial cases, narcolepsy without cataplexy or without HLA-DQB1*0602, recurrent hypersomnias, and symptomatic cases (eg, Parkinson disease, depression, Prader-Willi syndrome, Niemann-Pick disease type C). The subject group also included 296 controls (healthy and with neurological disorders). INTERVENTION: Venopuncture for HLA typing, lumbar puncture for CSF analysis, primary diagnosis using the International Classification of Sleep Disorders, Stanford Sleep Inventory for evaluation of narcolepsy, and sleep recording studies. MAIN OUTCOME MEASURES: Diagnostic threshold for CSF hypocretin-1, HLA-DQB1*0602 positivity, and clinical and polysomnographic features. RESULTS: HLA-DQB1*0602 frequency was increased in narcolepsy with typical cataplexy (93% vs 17% in controls), narcolepsy without cataplexy (56%), and in essential hypersomnia (52%). Hypocretin-1 levels below 110 pg/mL were diagnostic for narcolepsy. Values above 200 pg/mL were considered normal. Most subjects with low levels were HLA-DQB1*0602-positive narcolepsy-cataplexy patients. These patients did not always have abnormal MSLT. Rare subjects without cataplexy, DQB1*0602, and/or with secondary narcolepsy had low levels. Ten subjects with hypersomnia had intermediate levels, 7 with narcolepsy (often HLA negative, of secondary nature, and/or with atypical cataplexy or no cataplexy), and 1 with periodic hypersomnia. Healthy controls and subjects with other sleep disorders all had normal levels. Neurological subjects had generally normal levels (n = 194). Intermediate (n = 30) and low (n = 3) levels were observed in various acute neuropathologic conditions. CONCLUSIONS: Narcolepsy-cataplexy with hypocretin deficiency is a genuine disease entity. Measuring CSF hypocretin-1 is a definitive diagnostic test, provided that it is interpreted within the clinical context. It may be most useful in cases with cataplexy and when the MSLT is difficult to interpret (ie, in subjects already treated with psychoactive drugs or with other concurrent sleep disorders).     

Delivery of recombinant adeno-associated virus by jet injection

The jet-injection technology was used for delivery of recombinant adeno-associated virus (rAAV). Although AAV-based vectors are an attractive tool in gene therapy, some methodological and technical problems of their targeted delivery remain to be solved. We tried to address some of these cell-targeting problems by using a new low-volume needleless injection device the Swiss Injector. First we tested, by electron microscopy, whether jet-injection would have any detrimental effect on rAAV particle integrity. Second, we compared transgene expression after infection of 293T cells with fired or control (non-fired) rAAV that expressed the green fluorescent protein (GFP), beta-galactosidase (beta-gal), the B7.1 molecule, and interleukin 2 (IL2). Third, an rAAV carrying the genes coding for beta-gal was jet-injected into mouse subcutaneous (s.c.) tumours. The staining of tumour cryosections revealed beta-gal expression 72 h after the delivery. Our study demonstrated the applicability of the Swiss Injector for the delivery of rAAV into tumour tissue without either vector particle integrity or the level of expression of the transgenes, as tested in vitro, being affected. The jet-injection technology could improve the distribution of vector particles in the tumour mass without leakage of liquid from the injection site.     

Alterations in mitochondria function and morphology in HT29 cells upon conditions inducing differentiation and apoptosis

Morphological and biochemical studies of HT29 cells treated with sodium butyrate and/or glucose-deprived revealed both apoptotic and differentiation response. The main apoptotic response was accompanied with an increase of floating cells. However, the ultrastructural analysis of adherent cells showed the typical apoptotic character of the nucleus in some of them. In addition, remarkable changes of mitochondria, assumed as early stages starting the apoptotic cascade, were observed. These changes were represented not only by alterations of mitochondrial morphology, but also by the number of mitochondria and their localization.     

Influence of the endothelial nitric oxide synthase polymorphism on the progression of autosomal dominant polycystic kidney disease and IgA nephropathy

BACKGROUND: The reason of variability of clinical course and progression to end-stage renal failure (ESRF) of two widespread chronic nephropathies-autosomal dominant polycystic kidney disease (ADPKD) and IgA nephropathy (IGAN) is not clear. The endothelial dysfunction is considered in the number of factors possibly influencing the prognosis of these nephropathies. Our study tried to verify the hypothesis that endothelial nitric oxide synthase (ecNOS) gene polymorphisms in intron 4 could have some relevance to the progression of ADPKD and/or IgA nephropathy. METHODS: We examined 128 Czech patients with ADPKD (62 males, 66 females) and 93 patients with IGAN (51 males, 42 females). As a control group we used 100 genetically unrelated healthy subjects (50 men, 50 women, mean age 51.2 +/- 8.2). The genomic DNA was amplified by polymerase chain reaction (PCR) and the products were separated on 1.5% agarose gel and visualized by ultraviolet transillumination. We compared homozygous subjects for ecNOSb allele with homozygous and heterozygous subjects for ecNOSa allele. RESULTS: The frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes were 19% (19/100) and 81% (81/100) in the control group. The frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes in ADPKD patients were: 26.6% (8/30) and 73.4% (22/30) in ADPKD patients with normal renal function, 30% (9/30) and 70% (21/30) in ADPKD with ESRF, 35.2% (18/51) and 64.8% (33/51) in young ADPKD patients, 60% (12/20) and 40% (8/20) in ADPKD patients with ESRF later than in 62 years. In IGAN the frequencies of ecNOSa/b + a/a and ecNOSb/b genotypes were 24% (12/50) and 76% (38/50) in IgA with normal renal function and 20.9 % (9/43) and 79.1% (38/43) in IgA with ESRF. Conclusion: Both in ADPKD and IGAN groups there was no significant difference in the frequencies of ecNOS genotypes between patients with normal renal function and age matched patients with ESRF and between patients with normal renal function and control group. The frequency of ecNOS a allele was significantly higher in a number limited group ADPKD patients with ESRF later than in 62 years (Chi-square test p < 0.05). This higher frequency of a allele among ADPKD patients with later onset of ESRF could suggest the trend of positive influence of a allele in ADPKD patients.