Lipid-Based Liquid Crystals As Carriers for Antimicrobial Peptides: Phase Behavior and Antimicrobial Effect

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Biochemical and epidemiological investigations of non-steroidal anti-inflammatory drug usage and related side effects in equids

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in equine veterinary practice. These drugs exert their effect by inhibiting cyclooxygenase (COX) enzymes, which control prostaglandin production, a major regulator of tissue perfusion. Two isoforms of COX enzymes exist: COX-1 is physiologically present in tissues, while COX-2 is up-regulated during inflammation and has been indicated as responsible for the negative effects of an inflammatory response. Evidence suggests that NSAIDs that inhibit only COX-2, preserving the physiological function of COX-1 might have a safer profile. Studies that evaluate the effect of NSAIDs on COX enzymes are all performed under experimental conditions and none uses actual clinical patients. The biochemical investigations in this work focus on describing the effect on COX enzymes activity of flunixin meglumine and phenylbutazone, two non-selective COX inhibitors and firocoxib, a COX-2 selective inhibitor, in clinical patients undergoing elective surgery. A separate epidemiological investigation was aimed at describing the impact that the findings of biochemical data have on a large population of equids. Electronic medical records (EMRs) from 454,153 equids were obtained from practices in the United Kingdom, United States of America and Canada. Information on prevalence and indications for NSAIDs use was extracted from the EMRs via a text mining technique, improved from the literature and described and validated within this Thesis. Further the prevalence of a clinical sign compatible with NSAID toxicity, such as diarrhoea, is reported along with analysis evaluating NSAID administration in light of concurrent administration of other drugs and comorbidities. This work confirms findings from experimental settings that NSAIDs firocoxib is COX-2 selective and that flunixin meglumine and phenylbutazone are non-selective COX inhibitors and therefore their administration carries a greater risk of toxicity. However the impact of this finding needs to be interpreted with caution as epidemiological data suggest that the prevalence of toxicity is in fact small and the use of these drugs at the labelled dose is quite safe.

Antimicrobial effect of polymeric biomaterials for bone infection treatment

Dissertação de mestrado em Bioquímica, apresentada à Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2016.

Studies of antihypertensive drug persistence and adherence in the Glasgow Blood Pressure Clinic

Hypertension (HTN) is a major risk factor for cardiovascular diseases including stroke, coronary heart disease (CHD), chronic renal failure, peripheral vascular disease, myocardial infarction, congestive heart failure and premature death. The prevalence of HTN in Scotland is very high and although a high proportion of the patients receive antihypertensive medications, blood pressure (BP) control is very low. Recommendations for starting a specific antihypertensive class have been debated between various guidelines over the years. Some guidelines and HTN studies have preferred to start with a combination of an antihypertensive class instead of using a single therapy, and they have found greater BP reductions with combination therapies than with monotherapy. However, it has been shown in several clinical trials that 20% to 35% of hypertensive patients could not achieve the target BP, even though they received more than three antihypertensive medications. Several factors were found to affect BP control. Adherence and persistence were considered as the factors contributing the most to uncontrolled hypertension. Other factors such as age, sex, body mass index (BMI), alcohol intake, baseline systolic BP (SBP), and the communication between physicians and patients have been shown to be associated with uncontrolled BP and resistant hypertension. Persistence, adherence and compliance are interchangeable terms and have been used in the literature to describe a patient’s behaviour with their antihypertensive drugs and prescriptions. The methods used to determine persistence and adherence, as well as the inclusion and exclusion criteria, vary between persistence and adherence studies. The prevalence of persistence and adherence have varied between these studies, and were determined to be high in some studies and low in others. The initiation of a specific antihypertensive class has frequently been associated with an increase or decrease in adherence and persistence. The tolerability and efficacy of the initial antihypertensive class have been the most common methods of explaining this association. There are also many factors that suggest a relationship with adherence and persistence. Some factors in previous studies, such as age, were frequently associated with adherence and persistence. On the other hand, relationships with certain factors have varied between the studies. The associations of age, sex, alcohol use, smoking, baseline systolic blood pressure (SBP) and diastolic BP (DBP), the presence of comorbidities, an increase in the number of pills and the relationship between patients and physicians with adherence and persistence have been the most commonly investigated factors. Most studies have defined persistence in terms of a patient still taking medication after a period of time. A medication possession ratio (MPR) ≥ 80 has been used to define compliance. Either of these terminologies, or both, have been used to estimate adherence. In this study, I used the same definition for persistence to identify patients who have continued with their initial treatment, and used persistence and MPR to define patients who adhered to their initial treatment. The aim of this study was to estimate the prevalence of persistence and adherence in Scotland. Also, factors that could have had an effect on persistence and adherence were studied. The number of antihypertensive drugs taken by patients during the study and factors that led to an increase in patients being on a combination therapy were also evaluated. The prevalence of resistance and BP control were determined by taking the BP after the last drug had been taken by persistent patients during five follow-up studies. The relationship of factors such as age, sex, BMI, alcohol use, smoking, estimated glomerular filtration rate (eGFR), and albumin levels with BP reductions for each antihypertensive class were determined. Information Services Division (ISD) data, which includes all antihypertensive drugs, were collected from pharmacies in Scotland and linked to the Glasgow Blood Pressure Clinic (GBPC) database. This database also includes demographic characteristics, BP readings and clinical results for all patients attending the GBPC. The case notes for patients who attended the GBPC were reviewed and all new antihypertensive drugs that were prescribed between visits, BP before and after taking drugs, and any changes in the hypertensive drugs were recorded. A total of 4,232 hypertensive patients were included in the first study. The first study showed that angiotensin converting enzyme inhibitor (ACEI) and beta-blockers (BB) were the most prescribed antihypertensive classes between 2004 and 2013. Calcium channel blockers (CCB), thiazide diuretics and angiotensin receptor blockers (ARB) followed ACEI and BB as the most prescribed drugs during the same period. The prescription trend of the antihypertensive class has changed over the years with an increase in prescriptions for ACEI and ARB and a decrease in prescriptions for BB and diuretics. I observed a difference in antihypertensive class prescriptions by age, sex, SBP and BMI. For example, CCB, thiazide diuretics and alpha-blockers were more likely to be prescribed to older patients, while ACEI, ARB or BB were more commonly prescribed for younger patients. In a second study, 4,232 and 3,149 hypertensive patients were included to investigate the prevalence of persistence in the Scottish population in 1- and 5-year studies, respectively. The prevalence of persistence in the 1-year study was 72.9%, while it was only 62.8% in the 5-year study. Those patients taking ARB and ACEI showed high rates of persistence and those taking diuretics and alpha blockers had low rates of persistence. The association of persistence with clinical characteristics was also investigated. Younger patients were more likely to totally stop their treatment before restarting their treatment with other antihypertensive drugs. Furthermore, patients who had high SBP tended to be non-persistent. In a third study, 3,085 and 1,979 patients who persisted with their treatment were included. In the first part of the study, MPR was calculated, and patients with an MPR ≥ 80 were considered as adherent. Adherence rates were 29.9% and 23.4% in the 1- and 5-year studies, respectively. Patients who initiated the study with ACEI were more likely to adhere to their treatments. However, patients who initiated the study with thiazide diuretics were less likely to adhere to their treatments. Sex, age and BMI were different between the adherence and non-adherence groups. Age was an independent factor affecting adherence rates during both the 1- and 5-year studies with older patients being more likely to be adherent. In the second part of the study, pharmacy databases were checked with patients' case notes to compare antihypertensive drugs that were collected from the pharmacy with the antihypertensive prescription given during the patient’s clinical visit. While 78.6% of the antihypertensive drugs were collected between clinical visits, 21.4% were not collected. Patients who had more days to see the doctor in the subsequent visit were more likely to not collect their prescriptions. In a fourth study, 3,085 and 1,979 persistent patients were included to calculate the number of antihypertensive classes that were added to the initial drug during the 1-year and 5-year studies, respectively. Patients who continued with treatment as a monotherapy and who needed a combination therapy were investigated during the 1- and 5-year studies. In all, 55.8% used antihypertensive drugs as a monotherapy and 44.2% used them as a combination therapy during the 1-year study. While 28.2% of patients continued with treatment without the required additional therapy, 71.8% of the patients needed additional therapy. In all, 20.8% and 46.5% of patients required three different antihypertensive classes or more during the 1-year and 5-year studies, respectively. Patients who started with ACEI, ARB and BB were more likely to continue as monotherapy and less likely to need two more antihypertensive drugs compared with those who started with alpha-blockers, non-thiazide diuretics and CCB. Older ages, high BMI levels, high SBP and high alcohol intake were independent factors that led to an increase in the probability of patients taking combination therapies. In the first part of the final study, BPs were recorded after the last drug had been taken during the 5 year study. There were 815 persistent patients who were assigned for this purpose. Of these, 39% had taken one, two or three antihypertensive classes and had controlled BP (controlled hypertension [HTN]), 29% of them took one or two antihypertensive classes and had uncontrolled BP (uncontrolled HTN), and 32% of the patients took three antihypertensive classes or more and had uncontrolled BP (resistant HTN). The initiation of an antihypertensive drug and the factors affecting BP pressure were compared between the resistant and controlled HTN groups. Patients who initiated the study with ACEI were less likely to be resistant compared with those who started with alpha blockers and non-thiazide diuretics. Older patients, and high BMI tended to result in resistant HTN. In the second part of study, BP responses for patients who initiated the study with ACEI, ARB, BB, CCB and thiazide diuretics were compared. After adjusting for risk factors, patients who initiated the study with ACEI and ARB were more respondent than those who took CCB and thiazide diuretics. In the last part of this study, the association between BP reductions and factors affecting BP were tested for each antihypertensive drug. Older patients responded better to alpha blockers. Younger patients responded better to ACEI and ARB. An increase in BMI led to a decreased reduction in patients on ACEI and diuretics (thiazide and non-thiazide). An increase in albumin levels and a decrease in eGFR led to decreases in BP reductions in patients on thiazide diuretics. An increase in eGFR decreased the BP response with ACEI. In conclusion, although a high percentage of hypertensive patients in Scotland persisted with their initial drug prescription, low adherence rates were found with these patients. Approximately half of these patients required three different antihypertensive classes during the 5 years, and 32% of them had resistant HTN. Although this study was observational in nature, the large sample size in this study represented a real HTN population, and the large pharmacy data represented a real antihypertensive population, which were collected through the support of prescription data from the GBPC database. My findings suggest that ACEI, ARB and BB are less likely to require additional therapy. However, ACEI and ARB were better tolerated than BB in that they were more likely to be persistent than BB. In addition, users of ACEI, and ARB have good BP response and low resistant HTN. Linkage patients who participated in these studies with their morbidity and mortality will provide valuable information concerning the effect of adherence on morbidity and mortality and the potential benefits of using ACEI or ARB over other drugs.

Applied evolution: An integrated approach to studying life history traits in response to drug selection

The use of chemical control measures to reduce the impact of parasite and pest species has frequently resulted in the development of resistance. Thus, resistance management has become a key concern in human and veterinary medicine, and in agricultural production. Although it is known that factors such as gene flow between susceptible and resistant populations, drug type, application methods, and costs of resistance can affect the rate of resistance evolution, less is known about the impacts of density-dependent eco-evolutionary processes that could be altered by drug-induced mortality. The overall aim of this thesis was to take an experimental evolution approach to assess how life history traits respond to drug selection, using a free-living dioecious worm (Caenorhabditis remanei) as a model. In Chapter 2, I defined the relationship between C. remanei survival and Ivermectin dose over a range of concentrations, in order to control the intensity of selection used in the selection experiment described in Chapter 4. The dose-response data were also used to appraise curve-fitting methods, using Akaike Information Criterion (AIC) model selection to compare a series of nonlinear models. The type of model fitted to the dose response data had a significant effect on the estimates of LD50 and LD99, suggesting that failure to fit an appropriate model could give misleading estimates of resistance status. In addition, simulated data were used to establish that a potential cost of resistance could be predicted by comparing survival at the upper asymptote of dose-response curves for resistant and susceptible populations, even when differences were as low as 4%. This approach to dose-response modeling ensures that the maximum amount of useful information relating to resistance is gathered in one study. In Chapter 3, I asked how simulations could be used to inform important design choices used in selection experiments. Specifically, I focused on the effects of both within- and between-line variation on estimated power, when detecting small, medium and large effect sizes. Using mixed-effect models on simulated data, I demonstrated that commonly used designs with realistic levels of variation could be underpowered for substantial effect sizes. Thus, use of simulation-based power analysis provides an effective way to avoid under or overpowering a study designs incorporating variation due to random effects. In Chapter 4, I 3 investigated how Ivermectin dosage and changes in population density affect the rate of resistance evolution. I exposed replicate lines of C. remanei to two doses of Ivermectin (high and low) to assess relative survival of lines selected in drug-treated environments compared to untreated controls over 10 generations. Additionally, I maintained lines where mortality was imposed randomly to control for differences in density between drug treatments and to distinguish between the evolutionary consequences of drug treatment versus ecological processes affected by changes in density-dependent feedback. Intriguingly, both drug-selected and random-mortality lines showed an increase in survivorship when challenged with Ivermectin; the magnitude of this increase varied with the intensity of selection and life-history stage. The results suggest that interactions between density-dependent processes and life history may mediate evolved changes in susceptibility to control measures, which could result in misleading conclusions about the evolution of heritable resistance following drug treatment. In Chapter 5, I investigated whether the apparent changes in drug susceptibility found in Chapter 4 were related to evolved changes in life-history of C. remanei populations after selection in drug-treated and random-mortality environments. Rapid passage of lines in the drug-free environment had no effect on the measured life-history traits. In the drug-free environment, adult size and fecundity of drug-selected lines increased compared to the controls but drug selection did not affect lifespan. In the treated environment, drug-selected lines showed increased lifespan and fecundity relative to controls. Adult size of randomly culled lines responded in a similar way to drug-selected lines in the drug-free environment, but no change in fecundity or lifespan was observed in either environment. The results suggest that life histories of nematodes can respond to selection as a result of the application of control measures. Failure to take these responses into account when applying control measures could result in adverse outcomes, such as larger and more fecund parasites, as well as over-estimation of the development of genetically controlled resistance. In conclusion, my thesis shows that there may be a complex relationship between drug selection, density-dependent regulatory processes and life history of populations challenged with control measures. This relationship could have implications for how resistance is monitored and managed if life histories of parasitic species show such eco-evolutionary responses to drug application.

Improvement of the oral praziquantel anthelmintic effect by cyclodextrin complexation

Schistosomiasis is a parasitic disease which kills a half million people per year, a I I over the world. Praziquantel (PZQ) is the drug-of-choice for schistosomiasis because of its effectiveness, ease of administration, and low cost. However, poor solubility restricts its delivery, especially via the oral route. In this study, we describe beta-cyclodextrin (beta-CD) complexation as an alternative to improve the PZQ bioavailability. Physicochemical analysis were performed to characterize the inclusion complex formed between PZQ and beta-CD. Differential scanning calorimetry (DSC) thermograms and morphological analysis using scanning electronic microscopy (SEM) gave evidences of the complex formation. Diffusion NMR experiments allowed determination of the fraction of PZQ bound to beta-CD (37%) and the association constant (941 +/- 47 M(-1)). The in vivo evaluation of the complexation on the effect of PZQ was performed on mice infected with Schistosoma mansoni (BH strain); after 15 days of treatment with the PZQ:beta-CD complex the efficacy, evaluated by the number of remaining alive worms, was 99%, against 59% elicited by plain PZQ.

Effect of myrrh and thyme on Trichinella spiralis enteral and parenteral phases with inducible nitric oxide expression in mice

Trichinellosis is a serious disease with no satisfactory treatment. We aimed to assess the effect of myrrh ( Commiphora molmol ) and, for the first time, thyme ( Thymus vulgaris L.) against enteral and encysted (parenteral) phases of Trichinella spiralis in mice compared with albendazole, and detect their effect on inducible nitric oxide synthase (iNOS) expression. Oral administration of 500 mg/kg of myrrh and thyme led to adult reduction (90.9%, 79.4%), while 1,000 mg/kg led to larvae reduction (79.6%, 71.3%), respectively. Administration of 50 mg/kg of albendazole resulted in adult and larvae reduction (94.2%, 90.9%). Positive immunostaining of inflammatory cells infiltrating intestinal mucosa and submucosa of all treated groups was detected. Myrrh-treated mice showed the highest iNOS expression followed by albendazole, then thyme. On the other hand, both myrrh and thyme-treated groups showed stronger iNOS expression of inflammatory cells infiltrating and surrounding encapsulated T. spiralis larvae than albendazole treated group. In conclusion, myrrh and thyme extracts are highly effective against both phases of T. spiralis and showed strong iNOS expressions, especially myrrh which could be a promising alternative drug. This experiment provides a basis for further exploration of this plant by isolation and retesting the active principles of both extracts against different stages of T. spiralis.

Synthesis, characterization, and preliminary application of new biocompatible nanogels useful as anticancer drug delivery systems

253 p.

Healing effect of Terminalia chebula Retz extract on second-degree burns in rats

Purpose: To investigate the healing effect of Terminalia chebula Retz Extract (TCRE) on seconddegree burns in rats. Methods: Male Sprague Dawley (SD) rats, weighing 200 – 220 g, were subjected to deep seconddegree skin burns by electrical scald instrument. The animals were divided into three groups as follows: (1) second-degree burns model (control) group, (2) burns model treated with 1 % silver sulfadiazine (SSD) group, and (3) burns model treated with 100 mg·mL-1 TCRE group. On days 3, 7 and 14 following the administration of the drug/extract, the wound area and histopathological changes in rat epidermis were evaluated for the various groups. The minimum inhibitory concentration (MIC) of TCRE on Staphyloccocus aureus, Pseudomonas aeruginosa and Escherichia coli were also assessed separately. Results: On day 14, the mean wound area of TCRE treatment group (0.25 ± 0.06 cm2) was significantly smaller than that of the control rats (2.71 ± 0.20 cm2, p < 0.01). The histological results indicate that the inflammatory cells disappeared and were replaced by new granulation tissue in the group treated with 100 mg·mL-1 TCRE by day 14. Compared with SSD group rats, the inflammatory cells and fibroblast and granulation tissues of burnt rats treated with 100 mg·mL-1 TCRE were same as those of rats that had no burns. The antibacterial results revealed that the MIC of TCRE on Staphyloccocus aureus, Pseudomonas aeruginosa and Escherichia coli was 3.13, 12.5 and 6.25 mg·mL-1, respectively. Conclusion: Terminalia chebula Retz. has potentials to be developed as an effective medicinal herb for the treatment of second-degree burns.

Effect of Arisaema erubescens (Wall) Schott rhizome extract on rheumatoid arthritis

Purpose: To investigate the anti-arthritic activity of the water extract of Rhizoma Arisaematis (WERA) using a collagen II -induced arthritis (CIA) rat model. Methods: CIA was induced in male Sprague-Dawley rats by intradermal injection of bovine collagen II in Complete Freund’s Adjuvant. The rats were treated with daily oral doses of WERA (100, 200, and 400 mg/kg) for 21 consecutive days. Methotrexate (MTX, 3 mg/kg), used as a positive control, was administered orally 2 times/week for 3 weeks. The severity of arthritis was evaluated using indices of paw swelling, arthritic score, body weight, thymus index, and spleen index. In addition, the serum levels of IL-1β, IL-6, IL-10, and TNF-α were measured. Results: All doses of WERA significantly inhibited paw edema (p < 0.01), decreased arthritis scores (p < 0.01) and spleen index (p < 0.05), and alleviated the weight loss associated with CIA in rats. Furthermore, TNF-α, IL-1β, and IL-6 serum levels were significantly decreased (p < 0.05) by all doses of WERA. By contrast, IL-10 serum levels were markedly increased (p < 0.05). Conclusion: WERA exerts therapeutic effects in CIA in rats by decreasing the serum levels of TNF-α, IL-1β, IL-6 and IL-10, suggesting WERA may be an effective candidate drug for treating human rheumatoid arthritis.

Anticonvulsant and sedative effect of Fufang Changniu pills and probable mechanism of action in mice

Purpose: To investigate the anticonvulsant and sedative effects of Fufang Changniu Pills (FCP) and its probable mechanism of action in mice. Methods: The water decoction of FCP was prepared and the main constituents were determined by high performance liquid chromatography (HPLC). The anticonvulsant activities of FCP were evaluated by maximal electroshock (MES) and pentylenetetrazole (PTZ)-induced seizures in mice. Pentobarbital sodium-induced sleeping time and locomotor activity measurements were performed to evaluate the sedative effects of FCP in mice. Finally, PTZ-induced chronic seizures were established, and expressions of gamma-aminobutyric acid A receptor (GABA-A) and glutamic acid decarboxylase 65 (GAD65) in the brains of the mice were assayed by western blot in order to explore the probable mechanisms of action of the drug. Results: Gallic acid, liquiritin, cinnamyl alcohol, cinnamic acid and glycyrrhizic acid were detected in FCP decoction. FCP (50, 100 and 200 mg/kg) showed significant anticonvulsant and sedative effects on epileptic mice induced by MES (p < 0.05) and PTZ (p < 0.05). Moreover, pentobarbital sodium-induced sleeping time and locomotor activity tests showed that FCP possesses sedative effect (p < 0.05). Western blot data indicate that FCP significantly up-regulated GABA-A and GAD 65 in the brains of chronic epileptic rats (p < 0.05). Conclusion: FCP has significant anticonvulsant and sedative effects, and the mechanism of its action may be related to the up-regulation of GABA-A and GAD 65 in mice brain.

Protective effect of rhamnopyranosyl vanilloyl isolated from Scrophularia ningpoensis Hemsl (Scrophulariaceae) root against acute liver injury in mice

Purpose: To investigate the protective effect of rhamnopyranosyl vanilloyl (RV) from Scrophularia ningpoensis root against tetrachloromethane (CCl4)-induced acute liver injury (ALI) in mice. Methods: RV was isolated from S. ningpoensis by column chromatography. ALI model of mice was established by intraperitoneal injection of CCl4. Liver index, liver function indices, as well as serum alanine transaminase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) were evaluated. Lipid peroxidation (LPO)-related indices, including malonaldehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Apoptotic proteins (Bcl-2, Bax and caspase-3) in liver tissue were determined by enzyme-linked immunosorbent assay (ELISA) and Western blot. Results: After treatment with RV (10, 20 or 40 mg/kg), liver index (5.65 - 5.21 vs. 6.68 %), ALT (90.18 - 79.68 vs. 112.47 U/L), AST (64.44 - 57.63 vs. 75.41 U/L) and TBIL (2.68 - 1.95 vs. 3.21 U/L) activities, as well as MDA (3.58 - 2.88 vs. 4.13 μmol/g), Bax and caspase-3 levels significantly (p < 0.05 or 0.01) decreased, compared with those in control group. After treatment with RV (10, 20 or 40 mg/kg), GSH (16.58 - 22.14 vs. 12.34 μmol/g), Bcl-2, SOD (86.45 - 107.61 vs. 68.43 U/mg) and GSH-Px (295.64 - 329.47 vs. 268.49 U/mg) levels or activities significantly (p < 0.05 or 0.01) increased, compared with those in control group. Conclusion: RV has protective effect against CCl4-induced ALI in mice, and the mechanisms involve the inhibition of LPO and apoptosis in liver cells. Thus, RV is a potential drug for the treatment of liver injury

Effect of Prunella vulgaris L extract on hyperprolactinemia in vitro and in vivo

Purpose: To investigate the anti-hyperprolactinemic activity of Prunella vulgaris L. extract (PVE) in vivo and in vitro. Methods: Rats were given intraperitoneal (i. p.) metoclopramide (MCP, 150 mg/kg daily) for 10 days to prepare hyperprolactinemia (hyperPRL) model. Bromocriptine was used as positive control drug. High (5.6 g/kg), medium (2.8 g/kg) and low (1.4 g/kg) doses of PVE were administered to hyperPRL rats. The effect of PVE on serum prolactin (PRL), estradiol (E2), progesterone (PGN), follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were investigated in the rats. MMQ cells derived from rat pituitary adenoma cells and GH3 cells from rat pituitary lactotropictumoral cells were used for in vitro experiments. The effect of PVE on PRL secretion were studied in MMQ cells and GH3 cells respectively. Results: Compared with the control group (446.21 ± 32.43 pg/mL), high (219.23 ± 10.62 pg/mL) and medium (245.47 ± 13.52 pg/mL) reduced PRL level of hyperPRL rats significantly (p 0.05). In MMQ cells, treatment with 5 mg/mL PVE or 10 mg/mL PVE) significantly suppressed PRL secretion and synthesis at 24h compared with controls (p < 0.01). Consistent with D2- action, PVE did not affect PRL in rat pituitary lactotropic tumor-derived GH3 cells that lack the D2 receptor expression, compared with controls. Conclusion: PVE showed anti-hyperPRL activity and can potentially be used for the treatment of hyperprolactinemi, but further studies are required to ascertain this

Parasitology of juvenile mullet (Mugil liza) and effect of formaldehyde on parasites and host

Few studies have been performed with parasites of marine and estuarine fish in southern Brazil. In the present study, unpublished results show the ways of parasitism of juvenile mullet by parasites. The toxicity of formaldehyde and the effectiveness of this chemotherapy in controlling parasites in reared juvenile mullet Mugil liza were also studied. Juvenile mullets (1 +/- 0.26 g; 4.1 +/- 0.4 cm) were exposed to different concentrations of 37% formaldehyde: control group and five formaldehyde concentrations which were tested: T1 (13.5), T2 (21.6), T3 (40.5), T4 (81) and T5 (135) mg L-1 with 8 fish per repetition in triplicate. To verify the drug effectiveness in parasitic control, juvenile mullets were exposed to 1 h prophylactic bath of 37% formaldehyde with a control group and five formaldehyde concentrations: T1 (67.5), T2 (135), T3 (270), T4 (405) and T5 (540) mg L-1, 8 fish per repetition in triplicate. Ligophorus cf. uruguayensis (Monogenoidea: Ancyrocephalidae) and Solostamenides cf. platyorchis (Monogenoidea: Microcotylidae) were identified in the gills. Digenea and Nematoda were observed in the intestines. This is the first occurrence of S. cf. platyorchis in Brazil. During the toxicity test, the LC50-96 h was estimated at 20.77 mg L-1 of formaldehyde. During the 1 h formaldehyde prophylactic bath, all parasites were eliminated in formaldehyde concentrations between 135 and 540 mg L-1. High survival rate was observed in all treatments. Values of prevalence and intensity of infestation observed in this study showed the potential damage caused by Monogenoidea to mullet. Formaldehyde baths with 135 mg L-1 are recommended to control Monogenoidea in mullet and the safe limits for formaldehyde use were presented. Besides, the endoparasites were tolerant to formaldehyde exposure. (C) 2012 Elsevier B.V. All rights reserved.

STUDIES OF FUNCTIONALIZED NANOPARTICLES FOR SMART SELF-ASSEMBLY AND AS CONTROLLED DRUG DELIVERY

This dissertation is related to the studies of functionalized nanoparticles for self-assembly and as controlled drug delivery system. The whole topic is composed of two parts. In the first part, the research was conducted to design and synthesize a new type of ionic peptide-functionalized copolymer conjugates for self-assembly into nanoparticle fibers and 3D scaffolds with the ability of multi-drug loading and governing the release rate of each drug for tissue engineering. The self-assembly study confirmed that such peptide-functionalized amphiphilic copolymers underwent different self-assembly behavior. The bigger nanoparticles were more easily assembled into nanoparticle fibers and 3D scaffolds with larger pore size, while the smaller nanoparticle underwent faster self-assembly to form more compact 3D scaffolds with smaller porosity but more stable structure. Controlled release studies confirmed the ability of governing simultaneous release of different model drugs with independent release rate from a same scaffold. Cytotoxicity tests showed that all synthesized peptides, copolymers and peptide-copolymer conjugates were biocompatible with SW-620 cell lines and NIH3T3 cell lines. This new type of self-assembled scaffolds combined the advantages of peptide nanofibers and versatile controlled release of polymeric nanoparticles to achieve simultaneous multi-drug loading and controlled release of each drug, uniform distribution and flexibility of hydrogel scaffolds. The investigations in second part were first to design and synthesize organic biocide-loaded nanoparticles for low-leaching wood preservation using a cost-effective one-pot method to synthesize amphiphilic chitosan-g-PMMA nanoparticles loading with ~25-28 wt.% of the fungicide tebuconazole with particle size of ~100 nm diameter by FESEM. FESEM analysis confirmed efficient penetration of nanoparticles throughout the treated wooden stake with dimension of 19 × 19 × 455 mm^3. Leaching studies showed that biocide introduced into sapwood via nanoparticles leached only ~9% compared with the amount leached from tebuconazole solution-treated control, while soil jar tests showed that the nanoparticle-treated wood blocks were effectively protected from biological decay tested against G. trabeum, a brown rot fungus. Copper oxide nanoparticles with and without polymer stabilizers were also investigated to use as inorganic wood preservatives to clarify the factor affecting copper leaching from treated wood. Copper oxide nanoparticles with uniform diameters of ~10 nm and ~50 nm were prepared, and the leachates from southern pine sapwood treated with these nanoparticles were analyzed. It was found by TEM and EDS analysis that significant numbers of nanoparticles leached from the treated wood. The 50 nm nanoparticles leached slightly less than a soluble copper salt control, but 10 nm nanoparticles leached substantially more than the control. The effect of polymer stabilizers on nanoparticle leaching was also investigated. Results showed that polymer stabilizers increased leaching. The trends showed that nanoparticle size was a major factor in copper leaching.