Anti-aging effect of nifuroxazide on skin changes of aged male rat models via modulating immunoreactivity of IL-6/NF-κB/Caspase-3.

PURPOSE: To evaluate nifuroxazide's (NIF's) anti-aging characteristics in a skin-aging rat model for the first time in order to create effective preventive measures and anti-aging skin therapies. MATERIALS AND METHODS: Thirty randomly selected aged male rats were assorted into three equal groups; aged control group, treated NIF I, aged rats were treated with NIF (10mg/kg, orally once daily for 14 consecutive days), and treated NIF II, aged rats were treated with NIF (20mg/kg, orally once daily for 14 consecutive days). Skin samples were obtained from the dorsal skin of the aged male rats and processed for tissue biochemical MDA, histological (Hx&E and Masson's Trichrome stains), and immunohistochemical (IL-6, NF-κB, and caspase-3) analysis. RESULTS: Group I aged male albino rat skin illustrated evident distorted epidermis and dermis, disorganization of collagen fibers with marked multiple spaces of collagen fibers loss in the dermis, marked reduction of total epidermal thickness and mean area percent of collagen fibers, elevated tissue MDA level and strong positive IL-6, NF-κB, and caspase-3 immune reaction. The anti-aging benefits of NIF on skin aging are demonstrated by a marked improvement in histological alterations in the form of a well-organized epidermis and dermis, most collagen fibers in the dermis appear closely packed, significant elevation of total epidermal thickness and mean area percent of collagen fibers, a significant decrease of tissue MDA level, and immunoexpression of the inflammatory markers, IL-6, and NF-κB, and the apoptotic marker caspase-3. CONCLUSIONS: This study found that group III, which received 20mg/kg of NIF, experienced more pronounced and noticeable improvements in skin aging than group II, which received 10mg/kg of NIF.

MicroRNAs and cytokines as potential predictive biomarkers for COVID-19 disease progression.

Host microRNAs can influence the cytokine storm associated SARS-CoV-2 infection and proposed as biomarkers for COVID-19 disease. In the present study, serum MiRNA-106a and miRNA-20a were quantified by real time-PCR in 50 COVID-19 patients hospitalized at Minia university hospital and 30 healthy volunteers. Profiles of serum inflammatory cytokines (TNF-α, IFN-γ, and IL-10) and TLR4 were analyzed by Eliza in patients and controls. A highly significant decrease (P value = 0.0001) in the expressions of miRNA-106a and miRNA-20a was reported in COVID-19 patients compared to controls. A significant decrease in the levels of miRNA-20a was also reported in patients with lymphopenia, patients having chest CT severity score (CSS) > 19 and in patients having O2 saturation less than 90%. Significantly higher levels of TNF-α, IFN-γ, IL-10 and TLR4 were reported in patients compared to controls. IL-10 and TLR4 levels were significantly higher in patients having lymphopenia. TLR-4 level was higher in patients with CSS > 19 and in patients with hypoxia. Using univariate logistic regression analysis, miRNA-106a, miRNA-20a, TNF-α, IFN-γ, IL-10 and TLR4 were identified as good predictors of disease. Receiver operating curve showed that the downregulation of miRNA-20a in patients having lymphopenia, patients with CSS > 19 and patients with hypoxia could be a potential biomarker with AUC = 0.68 ± 0.08, AUC = 0.73 ± 0.07 and AUC = 0.68 ± 0.07 respectively. Also, ROC curve showed accurate association between the increase of serum IL-10 and TLR-4 and lymphopenia among COVID-19 patients with AUC = 0.66 ± 0.08 and AUC = 0.73 ± 0.07 respectively. ROC curve showed also that serum TLR-4 could be a potential marker for high CSS with AUC = 0.78 ± 0.06. A negative correlation was detected between miRNA-20a with TLR-4 (r = - 0.30, P value = 0.03). We concluded that, miR-20a, is a potential biomarker of COVID-19 severity and blockade of IL-10 and TLR4 may constitute a novel therapy for COVID-19 patients.

Comparative study on the therapeutic effects of bone marrow mesenchymal stem cells versus platelet rich plasma on the pancreas of adult male albino rats with streptozotocin-induced type 1 diabetes mellitus.

BACKGROUND: The optimal treatment for autoimmune type 1 diabetes mellitus (T1DM) is endogenous regeneration of the pancreatic beta-cell. This can be achieved either by transplanting bone marrow mesenchymal stem cells (BMSCs) or injecting platelet-rich plasma (PRP). Current research reviewed a T1DM model and compared the effect of BMSCs on exocrine and endocrine pancreas portions versus PRP. MATERIALS AND METHODS: Rats were divided into four groups: Control group, Diabetic group (single streptozotocin dose 60 mg/kg IP), Diabetic + PRP group (PRP, 0.5 mL/kg SC twice weekly/4 weeks given to diabetic rats) and Diabetic + BMSCs group (1 mL of PKH26 labelled MSCs suspension in buffer phosphate solution, 3 × 106 cells/mL IV to diabetic rats). Glucose, amylase and lipase levels were calculated and pancreases were designed for light, electron microscopic, immunohistochemistry, morphometry and statistical analysis. RESULTS: Diabetic rats exhibited elevated glucose, decreased amylase and lipase compared to control rats. In addition, variable histological degenerative changes in the form of congested blood vessels have been identified with a significant increase in the mean area percentage of collagen, a significant decrease in the diameter of the islets, the number of cells in the islets of Langerhans and the number of zymogen granules. Ultrastructural findings exhibited distorted Golgi apparatus morphology, degenerated mitochondria, pyknotic nuclei, and few secretory beta-cell granules. CONCLUSIONS: Administration of BMSCs to diabetic group significantly increased the number of cells and diameter of Langerhans islets and the number of zymogen granules compared to Diabetic group as well as Diabetic + PRP group. BMSCs could be considered more efficient than PRP in the treatment of type 1 diabetes.

Effect of preservative-free and preserved prostaglandin analogues on the histology of cornea of adult male guinea pigs following repeated exposure.

BACKGROUND: Glaucoma is a group of eye diseases that can cause vision loss. Prostaglandin analogues (PGAs) are known to be first-line treatment for patients with glaucoma. Latanoprost is a good, efficient and well-tolerated PGA that is currently available as latanoprost with benzalkonium chloride (BAC) (Xalatan) and preservative-free (PF) prostaglandin analogue latanoprost (Monopost). Lately, using PF anti-glaucoma agents has been considered an essential procedure for enhancing glaucoma care. This study aimed to analyse the histological changes within the corneal tissue with the use of currently available preserved prostaglandins-derived eye drops and PF prostaglandin analogue. MATERIALS AND METHODS: In this study, 40 male guinea pigs were divided into four equal groups. Control group, Latanoprost with 0.02% BAC-treated group, Recovery group and PF latanoprost-treated group. After 2 months, the corneal tissues of guinea pigs were prepared for light and electron microscopic studies; morphometric and statistical studies were performed. RESULTS: Our results indicated that guinea pigs treated with latanoprost with BAC exhibited ocular surface changes: there was epithelial thinning with desquamation, the stroma showed irregularly arranged collagen fibres and small keratocytes. Morphometrically, there was a marked decrease in the thickness of epithelium and number of keratocytes. Negative periodic acid Schiff (PAS) reaction was observed in some parts of the epithelial basement membrane. The epithelium gave a strong positive immunoreactivity for Bcl-2-associated X protein (BAX). Guinea pigs left to recover exhibited improvement, while treatment of animals with PF latanoprost resulted in nearly normal corneal structure. CONCLUSIONS: In conclusion, PF prostaglandin anti-glaucoma medication seems to be better and have protective effect on cornea of male guinea pigs than prostaglandins with BAC preservative.

Emergency department mortality: Fair and square.

OBJECTIVE: This study explored the therapeutic approaches used for end-of-life (EOL) patients admitted to the emergency department (ED) and examined whether the decision to perform life-extending treatment (LET) or to allow natural death (AND) depends on patient characteristics, medical staff variables, and ED setting. METHODS: A retrospective archive study was conducted from January 2015 to December 2017 in the ED of a tertiary hospital. The study sample were 674 EOL patients who had died in the ED. For each patient, data were collected and measured for dying process (LET vs. AND), patient characteristics, ED-setting variables, and medical-staff characteristics. RESULTS: The proportion of EOL patients undergoing LET increased from 18.1% in 2015 to 25.9% in 2016 and to 30.3% in 2017 (p = .010), and a quarter of them were treated by emergency medical services. Males tended to receive LET more than females (p < .001). An association was found between Jewish physicians and nurses and AND (p = .001). Heavier workload in the ED and greater severity of the triage classification predicted more LET (OR-1.67, CI = 1.05-1.76, p = .003 and OR = 1.42, CI-0.60-0.81, p < .001, respectively). Receiver operating characteristic analysis showed that patient characteristics contributed most crucially to the therapeutic approaches (C statistic 0.624-0.675, CI-0.62-0.71). CONCLUSIONS: The therapeutic approach used for EOL patients in the ED depends on variables in all three treatment layers: patient, medical staff, and ED setting. Applicable national programs should be developed to ensure that no external factors influence the dying-process decision.

Steroid therapy in children with fulminant hepatitis A.

Fulminant hepatic failure is a life-threatening disease. Hepatitis A virus (HAV) can cause fulminant hepatic failure and death in about 0.2% of cases. Extensive destruction of infected hepatocytes by immune-mediated lysis is thought to be the cause. We aimed to evaluate the use of steroid therapy in children with fulminant HAV. This study included 33 children with fulminant HAV in two groups. Steroid group: comprised of 18 children who received prednisolone (1 mg/kg/d) or its equivalent dose of methylprednisolone, and the nonsteroid group: comprised another 15 children who did not receive steroid therapy. Age and sex were matched for both groups (P > .05), and they were comparable regarding baseline clinical and laboratory characteristics. Of the steroid group, 15 patients survived and 3 died, while in the nonsteroid group, 4 patients survived and 11 died (P = .001). Of the living patients, 15 of 19 (78.9%) received steroids while only 3 of 14 (21.4%) of the dead patients received steroids (P = .001). Stepwise regression analysis showed that steroid therapy was the only independent variable associated with recovery (P = .001). Steroid therapy in children with fulminant HAV associated significantly with improved outcome and survival. Future studies on a larger population size are strongly recommended.

Serum levels of psoriasin (S100A7) and koebnerisin (S100A15) as potential markers of atherosclerosis in patients with psoriasis.

BACKGROUND: Psoriasin (S100A7) and koebnerisin (S100A15) are proinflammatory proteins upregulated in psoriasis, but their relation to atherosclerosis remains unclear. AIM: To evaluate the role of serum psoriasin and koebnerisin as possible markers for subclinical atherosclerosis in patients with psoriasis. METHODS: Serum levels of psoriasin and koebnerisin were measured by ELISA in 45 patients with psoriasis and in 45 healthy controls (HCs). Intima-media thickness (IMT) of the right and left common carotid arteries was measured to detect the presence of subclinical atherosclerosis. Clinical severity of psoriasis was estimated using the Psoriasis Area and Severity Index (PASI). RESULTS: Compared with HCs, patients with psoriasis had significantly higher levels of psoriasin (26.61 ± 22.45 ng/mL vs. 6.31 ± 1.68 ng/mL, P < 0.001) and koebnerisin (21.2 ± 13.12 ng/mL vs. 12.2 ± 4.67 ng/mL, P = 0.001), and significantly higher IMT values (1.07 ± 0.4 mm vs. 0.61 ± 0.1 mm, P < 0.001). A positive correlation was observed between IMT and PASI (r = 0.78, P < 0.001), serum psoriasin (r = 0.48, P > 0.01) and serum koebnerisin (r = 0.48, P < 0.01). Patients with psoriasis with subclinical atherosclerosis had higher serum levels of koebnerisin compared with patients without subclinical atherosclerosis (P = 0.04), which was not observed for psoriasin (P = 0.94). CONCLUSION: Serum psoriasin and koebnerisin correlate with IMT, underlining their value as a potential link between psoriasis and atherosclerosis. In particular, koebnerisin seems to be a useful marker of subclinical atherosclerosis in patients with psoriasis.

Mouse Nudt13 is a Mitochondrial Nudix Hydrolase with NAD(P)H Pyrophosphohydrolase Activity.

The mammalian NUDT13 protein possesses a sequence motif characteristic of the NADH pyrophosphohydrolase subfamily of Nudix hydrolases. Due to the persistent insolubility of the recombinant product expressed in Escherichia coli, active mouse Nudt13 was expressed in insect cells from a baculovirus vector as a histidine-tagged recombinant protein. In vitro, it efficiently hydrolysed NADH to NMNH and AMP and NADPH to NMNH and 2',5'-ADP and had a marked preference for the reduced pyridine nucleotides. Much lower activity was obtained with other nucleotide substrates tested. K m and k cat values for NADH were 0.34 mM and 7 s-1 respectively. Expression of Nudt13 as an N-terminal fusion to green fluorescent protein revealed that it was targeted exclusively to mitochondria by the N-terminal targeting peptide, suggesting that Nudt13 may act to regulate the concentration of mitochondrial reduced pyridine nucleotide cofactors and the NAD(P)+/NAD(P)H ratio in this organelle and elsewhere. Future studies of the enzymology of pyridine nucleotide metabolism in relation to energy homeostasis, redox control, free radical production and cellular integrity should consider the possible regulatory role of Nudt13.

Modified Adenovirus Reduces De Novo Peritoneal Adhesions in Rats and Limits Off-Target Transfection. Role of EZH2 in Adhesion Formation.

AIM OF THE STUDY: Adenovector encoding tissue plasminogen activator (tPA) was shown to reduce experimental peritoneal adhesion. We investigated the targeting potential of our modified adenovector, its ability to reduce adhesions and the epigenetic role of histone methyltransferase EZH2 in adhesion formation. MATERIALS AND METHODS: Control lacZ, nonmodified tPA or modified tPA vectors were instilled in the peritoneal cavity after injury in de novo adhesions or after lysis of adhesions in recurrent adhesions. Adhesion severity was scored and adhesions and liver tissues were examined for adenovirus E4 gene and tPA mRNA expression. Levels of tPA, plasminogen activator inhibitor-1 (PAI-1), transforming growth factor-ß1 (TGF-ß1), and EZH2 expression were measured. RESULTS: E4 transcripts were detected in adhesions of nonmodified and modified and in livers of nonmodified but not in livers of modified de novo adhesions. Both nonmodified (p = 0.021) and modified vectors (p = 0.036) reduced the severity of de novo adhesions compared to lacZ vector. Levels of tPA in nonmodified (p = 0.021) and modified adhesions (p = 0.001) were elevated while PAI-1 (p = 0.013 and p = 0.001, respectively) and TGF-ß1 levels (p = 0.002 and p = 0.016, respectively) were reduced compared with lacZ group. All vectors were not expressed in recurrent adhesions and severity score were not different among groups. EZH2 levels were elevated in de novo nontreated (p = 0.001) and was further increased in recurrent (p = 0.001) nontreated adhesions compared with noninjured peritoneum. CONCLUSION: Modified adenovirus successfully targeted de novo adhesions but not liver tissues and reduced the severity of de novo adhesions. EZH2 is involved in the development and progression of peritoneal adhesions.

Towards the bioequivalence of pressurised metered dose inhalers 1: design and characterisation of aerodynamically equivalent beclomethasone dipropionate inhalers with and without glycerol as a non-volatile excipient.

A series of semi-empirical equations were utilised to design two solution based pressurised metered dose inhaler (pMDI) formulations, with equivalent aerosol performance but different physicochemical properties. Both inhaler formulations contained the drug, beclomethasone dipropionate (BDP), a volatile mixture of ethanol co-solvent and propellant (hydrofluoroalkane-HFA). However, one formulation was designed such that the emitted aerosol particles contained BDP and glycerol, a common inhalation particle modifying excipient, in a 1:1 mass ratio. By modifying the formulation parameters, including actuator orifice, HFA and metering volumes, it was possible to produce two formulations (glycerol-free and glycerol-containing) which had identical mass median aerodynamic diameters (2.4µm±0.1 and 2.5µm±0.2), fine particle dose (⩽5µm; 66µg±6 and 68µg±2) and fine particle fractions (28%±2% and 30%±1%), respectively. These observations demonstrate that it is possible to engineer formulations that generate aerosol particles with very different compositions to have similar emitted dose and in vitro deposition profiles, thus making them equivalent in terms of aerosol performance. Analysis of the physicochemical properties of each formulation identified significant differences in terms of morphology, thermal properties and drug dissolution of emitted particles. The particles produced from both formulations were amorphous; however, the formulation containing glycerol generated particles with a porous structure, while the glycerol-free formulation generated particles with a primarily spherical morphology. Furthermore, the glycerol-containing particles had a significantly lower dissolution rate (7.8%±2.1%, over 180min) compared to the glycerol-free particles (58.0%±2.9%, over 60min) when measured using a Franz diffusion cell. It is hypothesised that the presence of glycerol in the emitted aerosol particles altered solubility and drug transport, which may have implications for BDP pharmacokinetics after deposition in the respiratory tract.

Towards the bioequivalence of pressurised metered dose inhalers 2. Aerodynamically equivalent particles (with and without glycerol) exhibit different biopharmaceutical profiles in vitro.

Two solution-based pressurised metered dose inhaler (pMDI) formulations were prepared such that they delivered aerosols with identical mass median aerodynamic diameters, but contained either beclomethasone dipropionate (BDP) alone (glycerol-free formulation) or BDP and glycerol in a 1:1 mass ratio (glycerol-containing formulation). The two formulations were deposited onto Calu-3 respiratory epithelial cell layers cultured at an air interface. Equivalent drug mass (∼1000ng or ∼2000ng of the formulation) or equivalent particle number (1000ng of BDP in the glycerol-containing versus 2000ng of BDP in the glycerol-free formulation) were deposited as aerosolised particles on the air interfaced surface of the cell layers. The transfer rate of BDP across the cell layer after deposition of the glycerol-free particles was proportional to the mass deposited. In comparison, the transfer of BDP from the glycerol-containing formulation was independent of the mass deposited, suggesting that the release of BDP is modified in the presence of glycerol. The rate of BDP transfer (and the extent of metabolism) over 2h was faster when delivered in glycerol-free particles, 465.01ng±95.12ng of the total drug (20.99±4.29%; BDP plus active metabolite) transported across the cell layer, compared to 116.17ng±3.07ng (6.07±0.16%) when the equivalent mass of BDP was deposited in glycerol-containing particles. These observations suggest that the presence of glycerol in the maturated aerosol particles may influence the disposition of BDP in the lungs.

Identification and evaluation of agents isolated from traditionally used herbs against Ophiophagus hannah venom.

The aim of this study was firstly to identify active molecules in herbs, that are traditionally used for the treatment of snake bite, such as Curcuma antinaia, Curcuma contravenenum, Andrographis paniculata, and Tanacetum parthenium; secondly to test similar structurally related molecules and finally to prepare and evaluate an efficient formulation against Ophiophagus hannah venom intoxification. Three labdane based compounds, including labdane dialdehyde, labdane lactone, and labdane trialdehyde and two lactones including 14-deoxy-11,12-didehydroandrographolide and parthenolide were isolated by column chromatography and characterised. Using the isolated rat phrenic nerve-hemidiaphragm preparation, the antagonistic effect of crude extracts, isolated compounds and prepared formulations were measured in vitro on the inhibition of the neuromuscular transmission. Inhibition on muscle contraction, produced by the 5 µg/mL venom, was reversed by test agents in organ bath preparations. A labdane trialdehyde, isolated from C. contravenenum, was identified as the best antagonising agent in the low micromolar range. Tests on formulations of the most potent C. contravenenum extract showed, that the suppository with witepsol H15 was an effective medicine against O. hannah venom. This study elucidated the active compounds, accounting for the antivenin activity of traditionally used herbs and suggested the most suitable formulation, which may help to develop potent medicines for the treatment of snake bite in the future.

Knowledge, attitudes and practices of primary health care physicians towards evidence-based medicine in Doha, Qatar.

Physicians worldwide are being encouraged to apply evidence-based medicine (EBM) to improve their clinical care. A cross-sectional questionnaire study was carried to determine the knowledge, attitudes and practices regarding EBM among 182 primary care physicians in Doha, Qatar. The current promotion of EBM was welcomed by most physicians (98.4%). While 92.2% had access to the Internet, this was mostly at home. The major perceived barriers to practising EBM in primary care were lack of free personal time (75.3%), limited resources and facilities (62.6%), no library in the locality (61.0%) and lack of training workshops and courses (61.0%). There was a statistically significant association between years since graduation and welcoming the EBM concept as well as with frequency of reading journals.

Knowledge, attitudes and practice of general practitioners towards complementary and alternative medicine in Doha, Qatar

A cross-sectional study of knowledge, attitudes and practice of general practitioners [GPs] towards complementary and alternative medicine [CAM] was conducted in Doha, Qatar. Out of 119 respondents, 39.1% reported poor knowledge about CAM. Self-reported knowledge was highest for counselling and psychotherapy [69.0%], diet and supplements [68.1%], acupuncture [45.2%], herbal medicine [47.3%] and massage [42.5%]. While 83.8% described their attitude to CAM as welcoming and 97.5% were interested to learn more about it, fewer [30.1%] had practised it before, referred patients [24.8%] or asked patients' about their use of CAM [34.8%]. Their own lack of knowledge and training in CAM was seen as a barrier to its use by 60.0% of the GPs

Knowledge, attitudes and practices of primary health care physicians towards evidence-based medicine in Doha, Qatar

Physicians worldwide are being encouraged ence-based medicine [EBM] to improve their clinical care. A cross-sectional questionnaire study was carried to determine the knowledge, attitudes and practices regarding EBM among 182 primary care physicians in Doha, Qatar. The current promotion of EBM was welcomed by most physicians [98.4%]. While 92.2% had access to the Internet, this was mostly at home. The major perceived barriers to practising EBM in primary care were lack of free personal time [75.3%], limited resources and facilities [62.6%], no library in the locality [61.0%] and lack of training workshops and courses [61.0%]. There was a statistically significant association between years since graduation and welcoming the EBM concept as well as with frequency of reading journals

Adenovirus-mediated overexpression of human tissue plasminogen activator prevents peritoneal adhesion formation/reformation in rats.

BACKGROUND: Tissue-plasminogen activator (tPA) demonstrated beneficial effects on peritoneal adhesion formation; however, its short half-life limits its continual fibrinolytic effect. Therefore, we delivered adenovirus encoding tPA to prevent adhesions. METHODS: Rats were subjected to peritoneal injury and assigned to two protocols. In de novo adhesion protocol, adenovirus encoding human tPA gene (Ad-htPA) was instilled after peritoneal injury in group 1 (n = 22), whereas group 2 received phosphate-buffered saline (PBS) (n = 24). In recurrent adhesion protocol, group 1 (n = 15) received the same Ad-htPA dose after adhesiolysis and group 2 (n = 13) received PBS. Adhesion severity was scored 1 week after ad-htPA instillation. Adhesions were analyzed for htPA mRNA by reverse transcription-polymerase chain reaction and levels of htPA, and fibrinolytic inhibitors PAI-1, TIMP-1, and TGF-beta1 were measured using enzyme-linked immunosorbent assay. RESULTS: htPA mRNA and protein were only expressed in adhesions from treated groups. A reduction in adhesion scores (P < .01) and in fibrinolytic inhibitors (P < .001) occurred in the treatment groups. Also, negative correlation was found (r = -.69, P < .01) between adhesion scores and htPA protein, but a positive correlation was found (r = .90, P < .01) between adhesion score and fibrinolytic inhibitors. No bleeding or wound complications were encountered. CONCLUSION: Administration of adenovector encoding htPA is safe and decreased de novo and recurrent peritoneal adhesions.

Angiotensin-converting enzyme inhibition and angiotensin AT(1)-receptor antagonism equally improve doxorubicin-induced cardiotoxicity and nephrotoxicity.

Doxorubicin (Dox) is a potent anticancer agent; its clinical use is limited for its marked cardiotoxicity and nephrotoxicity. The present study investigated the possible protective effect of telmisartan, an angiotensin AT(1)-receptor blocker versus captopril, an angiotensin-converting enzyme inhibitor, on Dox-induced cardiotoxicity and nephrotoxicity in rats. Rats were allocated into four groups. Control group, Dox group, Dox+telmisartan group, and Dox+captopril group. Cardiotoxicity and nephrotoxicity were assessed biochemically and histopathologically. Frozen heart and kidney specimens were used for estimation of lipid peroxides product (MDA), reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) and nitric oxide (NO). Expression of induced nitric oxide synthase (iNOS) was detected by immunohistochemistry. Coadministration of either telmisartan or captopril with Dox equally decreased the biochemical markers of both cardiotoxicity (LDH and CK-MP) and nephrotoxicity (urea and creatinine). Both telmisartan and captopril attenuated the effects of Dox on oxidative stress parameters and NO. Histopathologically, coadministration of either drug with Dox was able to attenuate Dox-induced myocardial fibrosis and renal tubular damage. Immunohistochemistry, expression of iNOS was increased in both cardiac and renal tissues. Both telmisartan and captopril significantly and equally attenuated the effect of Dox on all measured parameters. These results suggested that telmisartan has protective effects equal to that of captopril against Dox-induced cardiotoxicity and nephrotoxicity; implying that angiotensin II pathway plays a role in Dox-induced cardiac and renal damage. The protective effect of either drug relies, at least in part, on their antioxidant effects and decreased the expression of iNOS.

Dynamics of a truncated prion protein, PrP(113-231), from (15)N NMR relaxation: order parameters calculated and slow conformational fluctuations localized to a distinct region.

Prion diseases are associated with the misfolding of the prion protein (PrP(C)) from a largely alpha-helical isoform to a beta-sheet rich oligomer (PrP(Sc)). Flexibility of the polypeptide could contribute to the ability of PrP(C) to undergo the conformational rearrangement during PrP(C)-PrP(Sc) interactions, which then leads to the misfolded isoform. We have therefore examined the molecular motions of mouse PrP(C), residues 113-231, in solution, using (15)N NMR relaxation measurements. A truncated fragment has been used to eliminate the effect of the 90-residue unstructured tail of PrP(C) so the dynamics of the structured domain can be studied in isolation. (15)N longitudinal (T(1)) and transverse relaxation (T(2)) times as well as the proton-nitrogen nuclear Overhauser effects have been used to calculate the spectral density at three frequencies, 0, omega(N,) and 0.87omega(H). Spectral densities at each residue indicate various time-scale motions of the main-chain. Even within the structured domain of PrP(C), a diverse range of motions are observed. We find that removal of the tail increases T(2) relaxation times significantly indicating that the tail is responsible for shortening of T(2) times in full-length PrP(C). The truncated fragment of PrP has facilitated the determination of meaningful order parameters (S(2)) from the relaxation data and shows for the first time that all three helices in PrP(C) have similar rigidity. Slow conformational fluctuations of mouse PrP(C) are localized to a distinct region that involves residues 171 and 172. Interestingly, residues 170-175 have been identified as a segment within PrP that will form a steric zipper, believed to be the fundamental amyloid unit. The flexibility within these residues could facilitate the PrP(C)-PrP(Sc) recognition process during fibril elongation.

Colchicine inhibits intimal hyperplasia and leukocyte VEGF expression in dogs.

BACKGROUND: Restenosis due to intimal hyperplasia following percutaneous transluminal angioplasty limits its long-term efficacy. We evaluated the effect of colchicine on the development of intimal hyperplasia following balloon angioplasty and on the vascular endothelial growth factor (VEGF) expression in leukocytes. MATERIAL AND METHODS: Adult dogs underwent balloon angioplasty of the right iliofemoral artery. Group 1 served as control, while groups 2 and 3 (six animals per group) received 0.1 and 0.5 mg/kg/d of colchicine p.o., respectively, starting 2 d before angioplasty and continued for 14 d. Before angioplasty and at day 14, blood samples were collected for drug toxicity analysis and the determination of leukocyte expression of VEGF. Animals were euthanized and iliofemoral arteries were perfusion fixed in situ and processed for histological and morphometric analysis. RESULTS: Balloon angioplasty without colchicine resulted in 446% (P < 0.001), 111% (P = 0.7), and 267% (P < 0.001) increase in intimal and medial thickness and intima/media ratio compared with contralateral uninjured iliofemoral arteries. Low-dose and high-dose colchicine resulted in 32% and 58% reduction in intima/media ratio, respectively (both P < 0.001). VEGF expression in leukocytes of control group was up-regulated (40%), but was down-regulated by 12% and 55%, respectively, in low-dose and high-dose colchicine groups at 2 wk after angioplasty compared with preangioplasty expression. The results of complete blood count and serum transaminases and creatinine were within normal range. CONCLUSION: This study demonstrates that oral colchicine for 2 wk significantly reduces intimal hyperplasia following balloon angioplasty in dogs through down-regulation of leukocyte VEGF expression and without apparent toxicity.