Repetitive Doses Research Articles

A systems biology approach to propose a new mechanism of regulation of repetitive prophylaxis of stable iodide on sodium/iodide symporter (NIS)

Our group showed that repetitive dose of potassium iodide (KI) for eight days offers an efficient protection for exposure to repeated radioactive emissions without adverse effects on adult rats. However, differential expression of genes implicated in Wolff-Chaikoff effect was observed. To understand the Wolff-Chaikoff regulation and its molecular constituents during repetitive administration of KI, a biochemical reaction network was constructed as a “geographical” map of the thyrocyte depicting iodide and thyroid hormone synthesis. Path analysis of the network has been performed to investigate the presence of a regulatory circuit of the node iodide to the node “nis transcription”. NIS is responsible for the uptake of KI and plays an important role in the Wolff-Chaikoff effect. The map is a source for the most updated information about iodide and thyroid hormone metabolism. Based on this map, we propose a hypothesis that shows a putative mechanism behind NIS regulation and KI uptake.

The use of dexamethasone in animals: implication for fertility, pregnancy and extrapolation of the animal data to humans

Exposure to dexamethasone causes numerous changes in various biological systems including the reproductive system and this has huge implication on fertility and pregnancy. Maternal dexamethasone administration promotes foetal lung maturation and thermoregulation in premature foetuses. This indication makes dexamethasone a drug of choice in maternal and neonatal human and veterinary health care. In addition, dexamethasone is widely used in human and veterinary medicine as potent anti-inflammatory, immunosuppressive and analgesic drug in all age categories. Although the safety profile of short term dexamethasone treatment has been established, there has been growing concern about the long term effects of dexamethasone therapy and its implication on fertility and pregnancy in animals and humans. Most of the indications or uses in humans are extrapolated from animal data. This necessitates the need to provide review updates of current literature on dexamethasone use in humans and animals as there are many intrinsic differences between humans and animals. The review provides an overview of dexamethasone uses, its merits and demerits on animal pregnancy and fertility and implication on extrapolation of the animal data to humans. The review is based on a comprehensive literature search of relevant materials between 1969 and 2016 as well as authors’ personal manuscript/abstract files and citations of known references and discussed according to the multidisciplinary clinical experience of the authors. Although low-dose dexamethasone treatment has been used in veterinary and human clinics for many years and produced no severe effect on vital functions, repetitive high dose or long-term therapy may be associated with more serious sequelae on fertility and pregnancy. While no animal truly recapitulates human pregnancy and fertility, it is recommended that results from animal data be subjected to rigorous preclinical pharmacokinetic scaling processes to justify possible extrapolation to humans. Keywords: Animals, Dexamethasone, Fertility, Humans, Pregnancy

Influence of Dichloroacetate Treatment on the Contributions of Rodent Brain, Heart, Liver and Kidney in the Expression of GSTZ1

Glutathione transferase zeta 1 (GSTZ1)/maleylacetoacetate isomerase (MAAI) is a critical enzyme in tyrosine catabolism via its trans‐isomerization of maleylacetoacetate (MAA) and maleylacetone (MA). GSTZ1 also catalyzes the metabolism of dichloroacetate (DCA), an investigational drug utilized in the treatment of cancer and mitochondrial diseases. The pharmacology and toxicity of DCA are influenced, in part, by subject age. DCA is a mechanism‐based inactivator of GSTZ1, and repetitive DCA dosing results in the auto‐inhibition of DCA metabolism. Consequently, the chronic use of DCA in adults can lead to development of reversible peripheral neuropathy. However this effect is seldom observed in children, who metabolize DCA more quickly than adults. The tissue accumulation of DCA, MAA, and MA, due to GSTZ1 degradation, may be a mechanism responsible for DCA toxicity. Although liver is the main site of GSTZ1 expression and activity, extrahepatic tissues also express GSTZ1. Following a single dose of DCA to female rats, GSTZ1 expression and activity were reduced in liver to a greater extent than in kidney, brain and heart. However, the role of extrahepatic tissues in metabolism of DCA, MAA, and MA following repeated doses of DCA that mimic therapy has not been studied. Therefore, we examined the relative tissue expression of GSTZ1 following multiple doses of DCA. Adult female Sprague Dawley rats, 8 per group, and juvenile female Sprague Dawley rats, 4 per group, were treated with sodium DCA (100 mg/kg) or sodium acetate (100 mg/kg) by oral gavage daily for 8 consecutive days. On the 9th day the tissues were removed and used to prepare cytosolic and mitochondrial subcellular fractions. GSTZ1 expression was then assessed via Western blot using a polyclonal antibody to rat GSTZ1. In comparison to the same tissue in acetate‐treated adults, the expression of cytosolic GSTZ1 remaining in the liver, kidney, heart and brain of DCA‐treated adults was 2.8%, 9.8%, 8.6% and 5.7%, respectively, with liver retaining the highest expression at 0.030 ± 0.009 ng GSTZ1/μg protein (mean ± S.E.). Similarly, the expression of cytosolic GSTZ1 in DCA‐treated juveniles was greatest in liver (0.044 ± 0.014), whereas extrahepatic tissues were 20‐fold lower. Expression of mitochondrial GSTZ1 in DCA‐treated animals was highest in juvenile liver (0.016 ± 0.005) and adult kidney (0.048 ± 0.007). Considering the higher protein yield and larger size of the liver, compared with extrahepatic tissues, most DCA metabolism is expected to occur in the liver, even after repeated dosing. Given the greater proportion of liver to body weight in young rats, the hepatic metabolism of DCA is predicted to be augmented within this age group. This is consistent with the higher clearance of DCA in young populations, as children may retain a higher capacity for the GSTZ1‐catalyzed metabolism of DCA due to relative liver size.Support or Funding InformationSupported in part by the US Public Health Service GM 099871This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Efficient in vitro photodynamic inactivation using repetitive light energy density on Candida albicans and Trichophyton mentagrophytes.

We compared the effectiveness of a single irradiation vs repetitive irradiation of light, for in vitro photodynamic inactivation (PDI) of Candida albicans and Trichophyton mentagrophytes, by using methylene blue (MB) and rose bengal (RB) as photosensitizers (PS). MB from 5 to 60 μM and RB from 0.5 to 10 μM, with energy densities from 10 to 60 J/cm2, were tested in C. albicans. We further optimize the PDI by reducing the light energy density and PS concentration for the single irradiation experiments by using repetitive doses (two and three times). MB was tested in C. albicans and T. mentagrophytes, and RB was tested in C. albicans. MB-PDI and RB-PDI in C. albicans significantly reduced the number of colony-forming units per milliliter (CFU/mL) when compared to the control groups. Using a single irradiation, over 99% growth inhibition of C. albicans was obtained with MB at 20 μM-60 J/cm2, and with RB at 1 μM-30 J/cm2 and 5 μM-10 J/cm2. With repetitive doses, similar results were obtained by reducing several times the light energy density and the PS concentration for C. albicans and T. mentagrophytes. The results showed that RB was more effective than MB for C. albicans inactivation. In addition, it is possible to significantly reduce the amount of PS and light energy density requirements by using repetitive irradiations in both genera tested. It makes the technique less invasive and could reduce the side effects in people extremely sensitive to the PS or the light.

Human Cytomegaly Virus Immunoglobulin as an Early Adjunctive Therapy Increased CMV-Free Survival after Heart Transplantation

Purpose There is still an ongoing discussion whether a prophylactic or a preemptive therapy against cytomegalovirus (CMV) is superior to reduce the incidence of CMV viremia, acute rejections (AR) or cardiac allograft vasculopathy (CAV) after heart transplantation (HTx). Thus, we evaluated different CMV treatment strategies in this setting. Methods HTx patients (n=56) were retrospectively studied regarding the end points of CMV-free survival viremia, AR, and CAV. The average follow-up was 4.15 years (355 days up to 7.5 years). Patients were classified into 3 groups according to their CMV therapy: preemptive therapy (PRE, n=19), prophylactic drug monotherapy (PROM, either valganciclovir for 3 months or early single dose of 1mg/kg/BW of CMV immunoglobulin, CMVIG, 2 weeks post-HTx, n=18) or prophylactic double drug therapy (PROD, valganciclovir for 3 months plus early single dose of CMVIG, n=19). For statistical analysis X2, X2-log-rank and T-Tests were used. Results Median patient survival was similar: PRE-group 2243 days, PROM-group 2417 days, and PROD-group 2410 days, respectively. However, the median CMV-viremia free survival was different among the groups: 1817 days in the PROD-group, 1459 days in the PROM-group and 1482 in the PRE-group (p=0.52). A subanalysis of patients with high risk for CMV infection (donor+/ recipient-CMV status) the CMV-free survival was significantly higher when patients received double prophylaxis therapy compared to the other two groups (p<0.01). Whether the incidence of AR nor of CAV was not significantly influenced by the choice of CMV treatment regimen. Antiviral medication was discontinuated in 10.5% PRE-group, 38.9% PROM-group, and 31.6% PROD-group, respectively. Conclusion Our study results suggest that early therapy with CMVIG as adjunct to antiviral treatment could prolong CMV-free survival in patients with CMV risk of infection. If a repetitive CMVIG dosing post-HTx will further reduce CMV infection needs to be explored in the future. There is still an ongoing discussion whether a prophylactic or a preemptive therapy against cytomegalovirus (CMV) is superior to reduce the incidence of CMV viremia, acute rejections (AR) or cardiac allograft vasculopathy (CAV) after heart transplantation (HTx). Thus, we evaluated different CMV treatment strategies in this setting. HTx patients (n=56) were retrospectively studied regarding the end points of CMV-free survival viremia, AR, and CAV. The average follow-up was 4.15 years (355 days up to 7.5 years). Patients were classified into 3 groups according to their CMV therapy: preemptive therapy (PRE, n=19), prophylactic drug monotherapy (PROM, either valganciclovir for 3 months or early single dose of 1mg/kg/BW of CMV immunoglobulin, CMVIG, 2 weeks post-HTx, n=18) or prophylactic double drug therapy (PROD, valganciclovir for 3 months plus early single dose of CMVIG, n=19). For statistical analysis X2, X2-log-rank and T-Tests were used. Median patient survival was similar: PRE-group 2243 days, PROM-group 2417 days, and PROD-group 2410 days, respectively. However, the median CMV-viremia free survival was different among the groups: 1817 days in the PROD-group, 1459 days in the PROM-group and 1482 in the PRE-group (p=0.52). A subanalysis of patients with high risk for CMV infection (donor+/ recipient-CMV status) the CMV-free survival was significantly higher when patients received double prophylaxis therapy compared to the other two groups (p<0.01). Whether the incidence of AR nor of CAV was not significantly influenced by the choice of CMV treatment regimen. Antiviral medication was discontinuated in 10.5% PRE-group, 38.9% PROM-group, and 31.6% PROD-group, respectively. Our study results suggest that early therapy with CMVIG as adjunct to antiviral treatment could prolong CMV-free survival in patients with CMV risk of infection. If a repetitive CMVIG dosing post-HTx will further reduce CMV infection needs to be explored in the future.

Safety Assessment of Potential Probiotic Lactobacillus fermentum MTCC-5898 in Murine Model after Repetitive Dose for 28Days (Sub-Acute Exposure).

Safety assessment of probiotic Lactobacillus fermentum MTCC-5898 (LF) with three doses (107, 109, and 1011cfu/day/animal) was carried on Swiss albino mouse weanlings for 28days using oral route. Health status of animals was monitored by physical assessment of body weight, organ indices, and histological appearances of liver and intestine along with measurement of hematological parameters (Hb, WBC, RBC count, MCHC, MCV, MCH), biochemical analytes in blood involving glucose, serum enzymes (ALT, AST and LDH), urea, creatinine, and lipid profile (total cholesterol, triglycerides, HDL, VLDL, LDL, and atherogenic index). LF showed no adverse effects on above parameters of general health status after continuous consumption for the experimental period. On the other hand, significant increase (p ≤ 0.05) in TGF-β (regulatory cytokine) and considerable decrease (p ≤ 0.05) in IFN-γ (pro-inflammatory cytokine) without any major changes in IL-4 and IL-12 in intestinal fluid on consumption of 109cfu/animal/day confirmed its dose-specific response for immune homeostasis. Further, safety of LF was also confirmed by insignificant changes in release of FITC-dextran (4kDa) in blood on its consumption than control group where only saline was given orally. Moreover, significantly (p ≤ 0.05) increased mRNA expression of claudin-1 and MUC-2 in intestinal epithelial cells on feeding L. fermentum further supported FITC-dextran permeability data which otherwise showed increased flux of FITC-dextran in blood on consumption of E. coli (109cfu/animal/day) due to intestinal damage. Thus, in vivo results confirmed that Lactobacillus fermentum MTCC 5898 is safe and non-toxic to weanling mice and may be considered for functional food application after clinical testing.

Immune tolerance attenuates gut dysbiosis, dysregulated uterine gene expression and high-fat diet potentiated preterm birth in mice

Preterm delivery accounts for 85% of perinatal morbidity and mortality. Although the consumption of a high-fat diet leads to exaggerated proinflammatory responses and, in pregnant women, increased rates of spontaneous preterm birth, the underlying mechanisms remain unclear. We sought to elucidate the mechanisms by which maternal consumption of a high-fat diet leads to a dysregulated immune response and, subsequently, spontaneous preterm birth. We performed 16S ribosomal RNA sequencing of DNA extracted and amplified from stool samples and compared the gut microbiomes of lipopolysaccharide-induced pregnant mice that were maintained on a high-fat diet compared to a normal control diet. Next, we sequenced the uterine transcriptomes of the mice. To test the effect of dampening of the immune response on the microbiome, transcriptome, and risk of spontaneous preterm birth, we induced immune tolerance with repetitive subclinical doses (0.2 mg/kg/week for 8 weeks) of endotoxin and performed 16S ribosomal RNA and uterine transcriptome sequencing on these immunotolerized mice. High-fat diet potentiates lipopolysaccharide-induced preterm birth by affecting the maternal gut microbiome and uterine transcriptome and reduces antioxidant capacity in a murine model. High-fat diet consumption also increases the colonization of the gut by 5 immunogenic bacteria and decreases colonization by Lachnospiraceae_NK4A136_group. Uteri from high-fat diet mice had increased expression of genes that stimulate the inflammatory-oxidative stress axis, autophagy/apoptosis, and smooth muscle contraction. Repetitive endotoxin priming protects high-fat diet dams from spontaneous preterm birth, increases colonization of the gut by Lachnospiraceae_NK4A136_group, decreases levels of immunogenic bacteria in the gut microbiome, and reduces the number of dysregulated genes after high-fat diet consumption from 994 to74. High-fat diet-potentiated spontaneous preterm birth is mediated by increased inflammation, oxidative stress, and gut dysbiosis. The induction of immune tolerance via endotoxin priming reverses these effects and protects high-fat diet dams from spontaneous preterm birth. Based on this work, the role of immunomodulation as a novel therapeutic approach to prevent preterm birth among women who consume high-fat diets should be explored.

Comparison of intracervical Foley catheter used alone or combined with a single dose of dinoprostone gel for cervical ripening: a randomised study

Prostaglandins and intracervical catheters are similarly effective for cervical ripening and for an induction of labour (IOL). Studies comparing the combined use with either method alone have administered repetitive doses of prostaglandins vaginally, which may increase the risk of tachysystole and chorioamnionitis. These disadvantages may be offset by co-administering a single dose of prostaglandin. Women (n = 110) planned for IOL, ≥37 weeks of gestation and with a Bishop Score of ≤6 were randomised into two groups: intracervical Foley catheter alone or combined with dinoprostone gel (0.5 mg) for 12 hours followed by oxytocin. The primary outcome was the IDI and the others were: change in Bishop Score, caesarean section (CS) requirement, any complications and neonatal outcome. The baseline Bishop was ≤4 in all and >80% were nulliparous. The post-ripening Bishop was significantly higher (6.67 vs. 5.98; p = .045) and the IDI was significantly lower in the combined group (16 hours and 16 minutes vs. 20 hours 44 minutes, p = .002). The CS rate was similar (29.1 vs. 25.5%; p = .669). No woman had hyperstimulation or chorioamnionitis and the neonatal outcomes were similar. Thus, co-administering one dose of an intracervical PGE2 gel with Foley was superior to Foley alone for cervical ripening and IOL.Impact statementWhat is already known on this subject? Prostaglandins and intracervical balloon catheters used individually are similarly effective for ripening an unfavourable cervix prior to the induction of labour (IOL). A few studies which have compared their found it to result in a shorter cervical ripening time and induction delivery interval (IDI) as compared to prostaglandins alone, though chorioamnionitis was a concern. When compared to balloon catheter used alone, combined use was either similarly or more effective. The studies comparing combined use with either method used alone have administered repetitive doses of prostaglandins vaginally, which may increase the risk of tachysystole, and possibly of chorioamnionitis. Co-administering a single dose of prostaglandin with a balloon catheter may offset these disadvantages.What do the results of this study add? A combined method for cervical ripening using a single dose of intracervical dinoprostone gel (PGE2, 0.5 mg) coadministered with an intracervical Foley catheter was superior to Foley catheter alone. The combined method improved the Bishop score after 12 hours and reduced the IDI significantly compared to the Foley catheter alone; while the caesarean rate and neonatal outcomes were similar. No woman had chorioamnionits or hyperstimulation.What are the implications of these findings for clinical practice and/or further research? The combined methods for cervical ripening should be compared to individual methods in more women, and the combinations may explore the use of other single use prostaglandins like the dinoprostone vaginal insert or misoprostol tablets.

Proposal for a Revised Classification of the Depth of Neuromuscular Block and Suggestions for Further Development in Neuromuscular Monitoring

Proposal for a Revised Classification of the Depth of Neuromuscular Block and Suggestions for Further Development in Neuromuscular Monitoring

Steroid pretreatment of organ donors does not impact on early rejection and long-term kidney allograft survival: Results from a multicenter randomized, controlled trial.

Steroid pretreatment of deceased donors reduces inflammation in allografts and is recommended by organ procurement guidelines. The impact on long‐term graft outcome, however, remains elusive. In this multicenter randomized controlled trial, 306 deceased donors providing organs for 455 renal transplant recipients were randomized to 1000 mg of methylprednisolone or placebo prior to organ procurement (ISRCTN78828338). The incidence of biopsy‐confirmed rejection (Banff>1) at 3 months was 23 (10%) in the steroid group and 26 (12%) in the placebo group (P = .468). Five‐year functional graft survival was 84% and 82% for the steroid group and placebo group, respectively (P‐value = .941). The hazard ratio of functional graft loss was 0.90 (95% confidence interval 0.57‐1.42, P = .638) for steroid vs placebo in a multivariate Cox model. We did not observe effect modification by any of the predictors of graft survival and treatment modality. A robust sandwich estimate was used to account for paired grafts of some donors. The mean estimated GFR at 5 years was 47 mL/min per 1.73 m2 in the steroid group and 48 mL/min per 1.73 m2 in the placebo group (P = .756). We conclude that steroid pretreatment does not impact on long‐term graft survival. In a donor population with higher risk of delayed graft function, however, repetitive and higher doses of steroid treatment may result in different findings.

Surface-engineered polyethyleneimine-modified liposomes as novel carrier of siRNA and chemotherapeutics for combination treatment of drug-resistant cancers

Modification of nanoparticle surfaces with PEG has been widely considered the gold standard for many years. However, PEGylation presents controversial and serious challenges including lack of functionality, hindered cellular interaction, allergic reactions, and stimulation of IgM production after repetitive dosing that accelerates blood clearance of the nanoparticles. We report the development of novel liposomal formulations surface-modified with a low molecular weight, branched polyethyleneimine (bPEI)–lipid conjugate for use as an alternative to PEG. The formulations had very good stability characteristics in ion- and protein-rich mediums. Protein adsorption onto the liposomal surface did not interfere with the cellular interaction. bPEI-modified liposomes (PEIPOS) showed enhanced association with three different cell lines by up to 75 times compared to plain or PEGylated liposomes and were without carrier toxicity. They also penetrated the deeper layers of 3D spheroids. Encapsulating paclitaxel (PTX) into PEIPOS did not change its main mechanism of action. PEIPOS complexed and intracellularly delivered siRNAs and downregulated resistance-associated proteins. Finally, tumor growth inhibition was observed in a mouse ovarian xenograft tumor model, without signs of toxicity, in animals treated with the siRNA/PTX co-loaded formulation. These complex-in-nature but simple-in-design novel liposomal formulations constitute viable and promising alternatives with added functionality to their PEGylated counterparts.

A putative mechanism of the Sodium/Iodide Symporter regulation during repetitive administration of stable Iodide described by a Systems Biology approach

A single dose of potassium iodide (KI) against a prolonged exposure to repeated radioactivity might not be effective enough to protect the thyroid. Our group have shown that a repetitive dose of KI for eight days offers efficient protection without adverse effects in male rats [1].

A whole-food approach to the in vitro assessment of the antitumor activity of gazpacho

Gazpacho is a traditional cold soup of the Mediterranean diet consisting of a main base of fresh pureed tomato and other vegetables. Tomato and tomato products have demonstrated chemopreventive activity against several types of cancer through in vitro studies, and in animal and clinical research. Here we have applied a whole-food approach for the preclinical assessment of the antitumor potential of gazpacho. Colon cancer cells (HT-29) were exposed to growing concentrations of gazpacho previously digested in vitro to simulate the delivery of bioactive molecules to colon cells after food consumption. The cytotoxicity of gazpacho ingredients was also tested in independent experiments. Programmed cell death by apoptosis was detected by using a multiparametric analysis that combines image-based bright-field and fluorescence cytometry, intracellular ATP level determination and enzymatic activity of caspase-3/7. Modulation of gene expression of key regulatory genes (p53, Bcl-2, BAX, and cyclin D1) was also investigated. Our cytotoxicity data showed that in vitro digestion of samples allowed the delivery of bioactive levels of antitumor phytochemicals to cultured cells. Controlled experiments showed significant repetitive dose and time-response cytotoxicity of gazpacho. Gazpacho digestates caused net cell death of cultures suggesting synergic activity among phytochemicals from its vegetable ingredients. Multiparametric and genetic analyses showed that gazpacho digestates can trigger colon cancer cells death by apoptosis through the activation of caspase cascade. Our results show that coupled in vitro methodology employed can be applied to investigate the antitumor potential of complex food matrixes or combinations of foods in the diet.

Concomitant behavioral and prefrontal cortex neuronal responses following acute and chronic methylphenidate exposure in adolescent and adult rats

There is growing concern that the psychostimulant Methylphenidate (MPD) is being abused for cognitive enhancement and recreation by healthy adults and adolescents seeking to improve their work or academic performance. This study concomitantly recorded the behavioral and prefrontal cortex (PFC) neuronal activity in freely behaving animals exposed to acute and chronic MPD doses (0.6, 2.5, and 10.0 mg/kg MPD) in order to compare MPD effects on adult and adolescent rats. The PFC is one of the primary brain areas affected by MPD and the drug of choice for treating ADHD. Moreover, the PFC is one of the last brain areas to complete development, suggesting that the behavioral and neurophysiological response to MPD may differ in adolescents and adults. In both adult and adolescent animals, it was observed that the same repetitive (chronic) dose of either 0.6, 2.5, or 10.0 mg/kg MPD elicited behavioral sensitization in some animals and tolerance in others, experimental biomarkers indicating drug of abuse symptoms, and the majority of PFC units recorded in animals expressing behavioral sensitization or tolerance to chronic MPD exposure responded by increasing and decreasing their neuronal firing rate, respectively. Further, it was shown that high doses of 10.0 mg/kg MPD significantly modified adolescent behavioral activity but did not impact adults suggesting that adolescents may be more receptive to chronic MPD exposure. These findings raise concerns regarding the use and abuse of MPD in normal, healthy individuals and support the notion that the adolescent PFC is more susceptible than the adult PFC to neuromodulation from chronic MPD use.

Development and characterization of late-stage diabetes mellitus and -associated vascular complications

Preclinical investigation is the key mark of medical research, as the major breakthroughs including treatment of devastating diseases in biomedical research have been led by animal studies. Type 2 diabetes mellitus (T2DM) is a predominant metabolic disorder having high prevalence of morbidity worldwide which create an urgent need to understand the pathogenesis, complication and other possible influences by development of appropriate animal model. High-fat diet (HFD) fed animals (21 days) were treated with single cycle of repetitive dose (SCRD) of streptozotocin (STZ; 40, 30 and 20 mg/kg/per day in three respective group at 1st, 3rd, and 5th day) and double cycle of repetitive dose (DCRD) of streptozocin (STZ) (20, 10 and 5 mg/kg/per day in three respective group at 1st, 3rd, and 5th day in one cycle and 21st, 23rd, 25th day in second cycle of treatment) to induce late-stage diabetic complications. Induction of hyperglycemia was assessed by fasting and postprandial blood glucose, HbA1c, insulin, C-peptide, pancreatic β-cells and dyslipidaemia up to 12 weeks. Combined treatment of HFD and STZ (20 mg/kg) in the DCRD manner were significantly induced late-stage diabetic complication with sustained hyperglycaemia, no mortality, increased HbA1c and dyslipidaemia, reduced insulin, C-peptide and beta cells. Moreover, biochemical and histological assessment of micro and macrovascular tissues confirmed the significant cardio-renal injury, endothelial and hepatic damage. The study confirmed the development of chronic diabetic model in rat mimicked to clinical pathology with associated micro and macrovascular abnormalities which can further explore the molecular aspects of diseases.

Conventional Anti-glioblastoma Chemotherapy Affects Proteoglycan Composition of Brain Extracellular Matrix in Rat Experimental Model in vivo.

Temozolomide (TMZ) is a conventional chemotherapy drug for adjuvant treatment of glioblastoma multiforme (GBM), often accompanied by dexamethasone (DXM) to prevent brain oedema and alleviate clinical side effects. Here, we aimed to investigate an ability of the drugs to affect normal brain tissue in terms of proteoglycan (PG) composition/content in experimental rat model in vivo. Age- and brain zone-specific transcriptional patterns of PGs were demonstrated for 8, 60, and 120 days old rats, and syndecan-1, glypican-1, decorin, biglycan, and lumican were identified as the most expressed PGs. DXM treatment affected both PG core proteins expression (mainly syndecan-1, glypican-1, decorin, biglycan, lumican, versican, brevican, and NG2) and heparan sulphate (HS)/chondroitin sulphate (CS) content in organotypic brain slice culture ex vivo and experimental animals in vivo in a dose-dependent manner. TMZ treatment did not result in the significant changes in PG core proteins expression both in normal rat brain hippocampus and cortex in vivo (although generics did), but demonstrated significant effects onto polysaccharide HS/CS content in the brain tissue. The effects were age- and brain zone-specific and similar with the age-related PGs expression changes in rat brain. Combination of TMZ with DXM resulted in the most profound deterioration in PGs composition and content in the brain tissue both at core protein and glycosaminoglycan levels. Taken together, the obtained results demonstrate that conventional anti-glioblastoma therapy affects proteoglycan structure and composition in normal brain tissue, potentially resulting in deterioration of brain extracellular matrix and formation of the favourable tumorigenic niche for the expansion of the residual glioma cells. During the TMZ chemotherapy, dose and regimen of DXM treatment matter, and repetitive low DXM doses seem to be more sparing treatment compared with high DXM dose(s), which should be avoided where possible, especially in combination with TMZ.

Baculovirus capsid display in vaccination schemes: effect of a previous immunity against the vector on the cytotoxic response to delivered antigens

The baculovirus Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) infects lepidopteran invertebrates as natural hosts, although it also has been used as display vector for vaccine development. In this work, we evaluated the effectiveness of repetitive doses of AcMNPV-based vectors on the cytotoxic immune response specific to the capsid-displayed heterologous antigen ovalbumin (OVA). Our results demonstrate that baculovirus vectors induce a boosting effect in the cytotoxic immune response to OVA, making possible to recover the levels obtained in the primary response. Moreover, mice preimmunized with wild-type baculovirus showed a complete lack of antigen-specific CD8 cytotoxic T lymphocytes (CTLs) that may be related to the presence of antibodies directed to baculoviral surface proteins, particularly to GP64. However, baculovirus was able to induce the innate immune response in spite of a previous response against this vector, although some quantitative differences reflect a distinct activation of the immune cells in prime and boost. This is the first report in which the novel capsid display strategy is evaluated in prime-boost schemes to improve efficient CTL responses.

Caudate nucleus neurons participate in methylphenidate function: Behavioral and neuronal recordings from freely behaving adolescent rats

Methylphenidate (MPD) is the most commonly prescribed psychostimulant for the treatment of attention-deficit hyperactivity disorder (ADHD). MPD acts on brain structures of the reward/motivation system, including the caudate nucleus (CN). The objective of this study was to investigate the acute and chronic dose response effects of MPD on CN neurons in freely behaving adolescent rats. Semi-microelectrodes were implanted into the CN of one hundred and sixty-three adolescent male Sprague-Dawley rats. On experimental day one (ED1), each rat was injected with 0.8 ml saline followed by an injection of MPD (0.6, 2.5, or 10.0 mg/kg). Behavioral and neuronal recordings of 60 min followed each injection. Throughout ED2-6, each rat remained in its home cage and received daily injections of a specific dose of MPD. ED7-9 consisted of a three-day washout period during which no injections were given. On the last day (ED10), each rat was returned to the testing chamber in its home cage and an identical protocol was performed as on ED1. The same repetitive (i.e. chronic) dose of MPD elicited behavioral sensitization in some animals and behavioral tolerance in others. After chronic MPD exposure, CN units recorded from rats expressing behavioral sensitization responded mainly with increased neuronal firing rates. Conversely, rats expressing behavioral tolerance responded mainly with decreased neuronal firing rates. These findings suggest a direct correlation between the behavioral and CN neurophysiological response to chronic MPD in adolescent animals.

Preemptive Analgesia in Total Knee Arthroplasty: Comparing the Effects of Single Dose Combining Celecoxib with Pregabalin and Repetition Dose Combining Celecoxib with Pregabalin: Double-Blind Controlled Clinical Trial.

Acute pain is the most common early complication after total knee arthroplasty causing delayed mobilization and increased demands of morphine, leading to higher operative cost. Several studies have assessed the effectiveness, side-effects, and ease of use of various analgesics. Preemptive analgesia with combined celecoxib and pregabalin has been reported to yield positive outcomes. In this randomized, double-blind controlled clinical trial, 30 subjects underwent surgery for total knee arthroplasty using 15-20mg bupivacaine 5% epidural anesthesia. All subjects were divided into three groups. Group 1 was given celecoxib 400mg and pregabalin 150mg 1 hour before the operation, Group 2 was given celecoxib 200mg and pregabalin 75mg twice daily starting from 3 days before the operation, and Group 3 was given a placebo. The outcome was measured with Visual Analog Scale, knee range of motion, and postoperative mobilization. There was a significant difference in postoperative morphine usage between the groups that were administered with preemptive analgesia and the placebo group, but no significant difference was found between Group 1 and Group 2 that were given preemptive analgesia at different doses. ROM and postoperative mobilization were not significantly different among the three groups. Two patients in the first group, one patient in the second group, and one patient in the third group developed nausea. Preemptive analgesia is proven to reduce postoperative usage of morphine independent of the dosage. We recommend the use of combined celecoxib and pregabalin as preemptive analgesia after the total knee arthroplasty procedure. This trial is registered with NCT03523832 (ClinicalTrials.gov).

Visual Attention Affects the Amplitude of the Transcranial Magnetic Stimulation-associated Motor-evoked Potential: A Preliminary Study With Clinical Utility.

The transcranial magnetic stimulation (TMS)-elicited motor-evoked potential (MEP) is a valuable measure for clinical evaluations of various neurological disorders and is used to determine resting motor threshold for repetitive TMS dosing. Although MEP amplitude is primarily associated with motor system function, there is evidence that nonmotor factors may also influence amplitude. This experiment tested the hypotheses that manipulation of 2 factors (visual attention, cognitive regulation) in human participants would significantly affect MEP amplitude. Blocks of MEPs were recorded from the dominant right hand as participants (N=20) were instructed to shift their visual attention (toward and away from the hand) and cognitively regulate the MEPs (rest, attenuate MEP amplitude, potentiate MEP amplitude) using their thoughts (6 blocks, 20 pulses/block, randomized, 110% resting motor threshold). MEP amplitude was significantly affected by the direction of visual attention; looking away from the hand led to higher amplitudes (P=0.003). The relationship with cognitive regulation was nonsignificant. The significant effect of visual attention on MEP suggests that this should be a standardized parameter in clinical and research studies. These data underscore the importance of rigorous reporting of methods and use of standardized practices for MEP acquisition and TMS dosing to ensure consistent clinical measurement and treatment.