Does Sericin, as a Novel Pleurodesis Agent, Have Higher Effectiveness Compared to Talcum Powder, Doxycycline, and Silver Nitrate Pleurodesis?

INTRODUCTION: The usefulness of sericin as pleurodesis agent has previously been described. Present study aims to compare sericin pleurodesis regarding success, effectiveness, tolerability, and side-effects. METHODS: Adult, 12-week-old Wistar-albino rats (n=60), divided to five groups as sericin, talcum-powder, doxycycline, silver-nitrate and control. Agents were administrated through left thoracotomy, rats sacrificed twelve-days after. RESULTS: Highest ratio of collagen fibers was observed in sericin group, and the intensity was higher than talcum-powder group (p<0.05). Compared to silver nitrate, sericin group displayed better mesothelial reaction, and multi-layer mesothelium was also better (p<0.05). Foreign body reaction and emphysema were less frequent in sericin group (p<0.05). The presence of biological tissue in parenchyma was less prominent in sericin group (p<0.05). Foreign body reaction on thoracic wall was less common in sericin group (p<0.05). Presence of biological tissue glue in thoracic wall was less prominent in sericin group (p<0.05). Glomerular degeneration was lower in sericin group compared to the silver nitrate group (p<0.05), and tubular degeneration was less common in sericin group than talcum group (p<0.05). Pericarditis was less common in sericin group compared to the other groups (p<0.05). CONCLUSION: As an intrinsic, natural glue protein, sericin protects the lung parenchyma and tissues, and its glue-like characteristics enable pleurodesis. The success of sericin in pleurodesis was demonstrated in the present study based on investigations of the pleurae. Being cost-effective and better tolerated agent associated with a low potential of side effects, sericin is more effective, less expensive and provides more lung parenchyma protection.

[Influence of Four Kinds of PPCPs on Micronucleus Rate of the Root-Tip Cells of Vicia-faba and Garlic].

In order to determine the degree of biological genetic injury induced by PPCPs, the genotoxic effects of the doxycycline (DOX), ciprofloxacin (CIP), triclocarban (TCC) and carbamazepine (CBZ) in the concentration range of 12.5-100 mg · L⁻¹ were studied using micronucleus rate and micronucleus index of Vicia-fabe and garlic. The results showed that: (1) When the Vicia-faba root- tip cells were exposed to DOX, CIP, TCC and CBZ, micronucleus rates were higher than 1.67 ‰ (CK1), it was significantly different from that of the control group (P < 0.05), and the micronucleus index was even greater than 3.5; With the increasing concentrations of the PPCPs, the micronucleus rates first increased and then decreased. (2) When the garlic root tip cells were exposed to DOX, CIP, TCC and CBZ respectively, the micronucleus rates were less than those of the Vicia-faba, while in most treatments significantly higher than that of the control group (0.67‰). The micronucleus index was higher than 3.5 in the groups exposed to CIP with concentrations of 25, 50, 100 mg · L⁻¹ and TCC and CBZ with concentrations of 25 mg · L⁻¹; With the increase of exposure concentrations, the micronucleus rate showed a trend of first increasing and then decreasing as well. (3) Under the same experimental conditions, the cells micronucleus rates of the garlic cells caused by the four tested compounds were significantly lower than those of Vicia-faba. (4) The micronucleus index of the root tip cells of Vicia-faba and garlic treated with the four kinds of compounds followed the order of CIP > CBZ > TCC > DOX. These results demonstrated that the four compounds caused biological genetic injury to root-tip cells of Vicia-faba and garlic, and the genetic damage caused to garlic was significantly lower than that to Vicia-faba. The damages caused by the four kinds of different compounds were also different.

Forward Programming of Cardiac Stem Cells by Homogeneous Transduction with MYOCD plus TBX5.

UNLABELLED: Adult cardiac stem cells (CSCs) express many endogenous cardiogenic transcription factors including members of the Gata, Hand, Mef2, and T-box family. Unlike its DNA-binding targets, Myocardin (Myocd)-a co-activator not only for serum response factor, but also for Gata4 and Tbx5-is not expressed in CSCs. We hypothesised that its absence was a limiting factor for reprogramming. Here, we sought to investigate the susceptibility of adult mouse Sca1+ side population CSCs to reprogramming by supplementing the triad of GATA4, MEF2C, and TBX5 (GMT), and more specifically by testing the effect of the missing co-activator, Myocd. Exogenous factors were expressed via doxycycline-inducible lentiviral vectors in various combinations. High throughput quantitative RT-PCR was used to test expression of 29 cardiac lineage markers two weeks post-induction. GMT induced more than half the analysed cardiac transcripts. However, no protein was detected for the induced sarcomeric genes Actc1, Myh6, and Myl2. Adding MYOCD to GMT affected only slightly the breadth and level of gene induction, but, importantly, triggered expression of all three proteins examined (α-cardiac actin, atrial natriuretic peptide, sarcomeric myosin heavy chains). MYOCD + TBX was the most effective pairwise combination in this system. In clonal derivatives homogenously expressing MYOCD + TBX at high levels, 93% of cardiac transcripts were up-regulated and all five proteins tested were visualized. IN SUMMARY: (1) GMT induced cardiac genes in CSCs, but not cardiac proteins under the conditions used. (2) Complementing GMT with MYOCD induced cardiac protein expression, indicating a more complete cardiac differentiation program. (3) Homogeneous transduction with MYOCD + TBX5 facilitated the identification of differentiating cells and the validation of this combinatorial reprogramming strategy. Together, these results highlight the pivotal importance of MYOCD in driving CSCs toward a cardiac muscle fate.

Intravitreal administration of known phototoxicants in the rabbit fails to produce phototoxicity: implications for phototoxicity testing of intravitreally administered small molecule therapeutics.

CONTEXT: Intravitreal (ITV) dosing has become a clinically important route of administration for the treatment of uveitis, endophthalmitis, retinal vein occlusion, diabetic macular edema and age-related macular degeneration. Despite this, there are no validated non-clinical models of phototoxicity for ITV products. OBJECTIVE: The objective of this study was to develop an ITV rabbit model of phototoxicity for use in assessing the photosafety of small molecules therapeutics. MATERIALS AND METHODS: Dutch Belted rabbits were intravitreally injected bilaterally with four known phototoxicants: 8-methoxypsoralen, lomefloxacin, doxycycline and stannsoporfrin. Triescence(®), a non-phototoxic triamcinolone acetonide steroid formulation designed for ITV administration, was used as a negative control. One eye was then irradiated with solar-simulated ultraviolet radiation for 30 min, 1 h after dosing, while the other eye was occluded, serving as a non-irradiated control. RESULTS: Despite the direct administration of known phototoxicants into the vitreous, no evidence of ocular phototoxicity was observed in any dose group. Direct (non-phototoxic) retinal toxicity was observed in the doxycycline dose group only. CONCLUSION: These data suggest that the posterior segment of the rabbit eye is protected against phototoxicity by anatomical and/or physiological mechanisms, and is not a useful model for the assessment of phototoxicity of intravitreally administered molecules.

Effectiveness and preclinical safety profile of doxycycline to be used "off-label" to induce therapeutic transgene expression in a phase I clinical trial for glioma.

Glioblastoma multiforme (GBM) is the most common malignant primary brain cancer in adults; it carries a dismal prognosis despite improvements in standard of care. We developed a combined gene therapy strategy using (1) herpes simplex type 1-thymidine kinase in conjunction with the cytotoxic prodrug ganciclovir to kill actively proliferating tumor cells and (2) doxycycline (DOX)-inducible Fms-like tyrosine kinase 3 ligand (Flt3L), an immune stimulatory molecule that induces anti-GBM immunity. As a prelude to a phase I clinical trial, we examined the efficacy and safety of this approach (Muhammad et al., 2010, 2012). In the present article, we investigated the efficacy and safety of the "off-label" use of the antibiotic DOX to turn on the high-capacity adenoviral vector (HC-Ad) encoding therapeutic Flt3L expression. DOX-inducible Flt3L expression in male Lewis rats was assessed using DOX doses of 30.8 mg/kg/day (low-DOX) or 46.2 mg/kg/day (high-DOX), which are allometrically equivalent (Voisin et al., 1990) to the human doses that are recommended for the treatment of infections: 200 or 300 mg/day. Naïve rats were intracranially injected with 1×10(9) viral particles of HC-Ad-TetOn-Flt3L, and expression of the therapeutic transgene, that is, Flt3L, was assessed using immunohistochemistry in brain sections after 2 weeks of DOX administration via oral gavage. The results show robust expression of Flt3L in the rat brain parenchyma in areas near the injection site in both the low-DOX and the high-DOX groups, suggesting that Flt3L will be expressed in human glioma patients at a DOX dose of 200 or 300 mg/day. These doses have been approved by the U.S. Food and Drug Administration to treat infections in humans and would thus be considered safe for an off-label use to treat GBM patients undergoing HC-Ad-mediated gene therapy in a phase I clinical trial.

The comparison of the effect of endodontic irrigation on cell adherence to root canal dentin.

The purpose of this study was to compare the effect of 10 different endodontic irrigation and chelating treatments on dental pulp stem cell (DPSC) attachment to root canal surfaces. Thirty-eight extracted human nondiseased single-canal teeth were cleaned and shaped using ProTaper and ProFile rotary instrumentation (Tulsa Dentsply, Tulsa, OK). The irrigation treatments investigated were 6% sodium hypochlorite, 2% chlorhexidine gluconate, Aquatine Endodontic Cleanser, and Morinda citrifolia juice. The irrigation treatments were used in conjunction with EDTA or MTAD. The instrumented teeth were immediately placed in cell culture with confluent DPSCs for 1 week. The number of attached DPSCs appeared to be correlated with the cytotoxicity of the root canal irrigating solution (analysis of variance, p < 0.0001). The presence or absence of the smear layer had little influence on DPSC activity (chi-square, p > 0.05). The results suggest that biocompatible irrigants are needed to promote DPSC attachment to root canal dentin, which is essential to accomplish some regenerative endodontic therapies.

[Retinal toxicity of intravitreal doxycycline. A pilot study]. / Toxicidad retiniana de doxiciclina intravítrea. Estudio piloto.

OBJECTIVE: To assess the retinal toxicity of varying concentrations of intravitreally administered doxycycline, a member of tetracycline family. METHODS: Fourteen New Zealand albino rabbits, divided into 5 groups, were used for this study. The initial concentration of doxycycline (100 mg) was titrated using 5% dextrose solution to the following concentrations in a volume of 0.1 ml: 2000 microg, 1000 microg, 500 microg, 250 microg, 125 microg, and 62.5 microg. Each concentration was injected into 2 rabbit eyes. Two control eyes received 0.1 ml of 5% dextrose solution. All animals were examined before and after injection using indirect ophthalmoscopy and slit-lamp biomicroscopy. Electroretinography (ERG) was performed on all animals prior to the intravitreal injection and 2 weeks post-injection. The animals were re-examined at this time by indirect ophthalmoscopy and slit-lamp biomicroscopy and were then subjected to euthanasia. Their eyes were enucleated and examined using light microscopy. RESULTS: The doxycycline injected group exhibited significant decreases in ERG of the eyes injected with 2000 microg, 1000 microg, 500 microg, and 250 microg/0.1 ml. No significant changes in the ERG were observed following the injection of lesser concentration levels. There were no signs of retinal toxicity on slit-lamp examination, indirect ophthalmoscopy, or light microscopy in all the eyes injected with doxycycline concentrations of 125 microg or lower. CONCLUSIONS: Doxycycline injected intravitreally appeared safe at concentrations of 125 microg/0.1 ml or less in albino rabbits. Intravitreal doxycycline may be beneficial, and is an inexpensive alternative drug which could be used in the treatment of bacterial endophthalmitis particularly against resistant Staphylococcus aureus organisms.