Encapsulation of curcumin loaded chitosan nanoparticle within poly (ε-caprolactone) and gelatin fiber mat for wound healing and layered dermal reconstitution

Hybrid electrospun fiber containing bioactive molecules, which offer the ability to deliver the cells into the wound bed, will help to achieve a high therapeutic effect. In this study, an electrospun polycaperlactone (PCL) and gelatin (Gela) scaffold containing curcumin loaded chitosan nanoparticle (NCs/Cur) was used to evaluate in vivo wound healing ability of the fabricated scaffolds. The electrospun hybrid scaffold seeded with human endometrial stem cells (EnSCs) showed desirable biocompatibility with the host immune system and wound healing ability in a full-thickness excisional animal model. The constructs were characterized for structural, mechanical and biochemical properties. Fourier transform infrared spectroscopy (FTIR) confirmed all typical absorption characteristics of PCL and Gela polymers as well as NCs and Cur. The results showed the perfect contact angle, wettability and degradability of hybrid fiber scaffolds with the good mechanical and structural characteristics including shape uniformity, pore size and porosity. The cell attachment and proliferation on the PCL/Gela/NCs/Cur was higher than PCL and PCL/Gela scaffolds. In term of the capability of hybrid scaffold and EnSCs in histological analysis, this novel tissue-engineered construct could be suggested as a skin substitute to repair injured skin and regenerative medicine application.

Enhanced sciatic nerve regeneration by poly-L-lactic acid/multi-wall carbon nanotube neural guidance conduit containing Schwann cells and curcumin encapsulated chitosan nanoparticles in rat

The main aim of this study was to improve the efficacy of peripheral nerve regeneration by an artificial neural guidance conduit (NGC) as a carrier to transplant allogeneic Schwann cells (SCs) and curcumin encapsulated chitosan nanoparticles (nanocurcumin). The conduit was prepared by poly-L-lactic acid (PLLA) and surface-modified multi-wall carbon nanotubes (mMWCNT) and filled with SCs and nanocurcumin. SCs play an important role in the regeneration of injured peripheral nerve and controlled curcumin release can decrease SCs apoptosis, and enhance the regeneration and functional recovery of injured peripheral nerves. The mechanical properties, contact angle, and cell biocompatibility experiments showed that the optimized concentration of mMWCNT inside PLLA wall of conduits was 0.15 wt%. The drug release experiments showed slower release of curcumin from nanocurcumin samples compared to nanocurcumin encapsulated inside NGC wrapped fibrin gel sample. It was found that simultaneous using of both SCs and curcumin inside NGC had a significant role in sciatic nerve regeneration in vivo. Histological examination revealed a significant increase in the number of axons in injured sciatic nerve following treatment by SCs and nanocurcumin compared to negative control group. Histological evaluation also revealed a significant decrease in the number of vessels in fibrin groups compared to positive control group. The results showed that there was no significant difference between the reaction time and sciatic functional index (SFI) values of rats with injured sciatic nerve treated by NGC/SCs/nanocurcumin sample and autograft sample. In conclusion, our results strongly showed that PLLA/mMWCNT nanofibrous conduit filled with fibrin gel containing SCs and nanocurcumin is a proper strategy for improving nerve regeneration after a nerve transaction in the rat.

Autocrine VEGF mediates the antiapoptotic effect of CD154 on CLL cells

CD154 is an important regulator of chronic lymphocytic leukaemia (CLL)-cell survival. In CLL, high serum levels of VEGF are a feature of advanced disease, and we and others have previously shown that CLL cells produce and secrete this growth factor. Since CD154 stimulates VEGF production in other cell types, and VEGF is known to promote cell survival, we examined whether the cytoprotection of CLL cells by CD154 involves VEGF. We report for the first time that treatment of CLL cells with CD154 results in increased VEGF production and demonstrate involvement of NF-kappaB in this process. Moreover, we show that CD154-induced CLL-cell survival is reduced by anti-VEGF-neutralising antibody and by inhibiting VEGF receptor (VEGFR) signalling with SU5416. However, addition of exogenous VEGF alone or blocking secreted autocrine VEGF had little or no effect on CLL-cell survival. We therefore conclude that CLL-cell cytoprotection in the presence of CD154 requires combined signalling by both CD40 and VEGFR. This combined signalling and resulting cytoprotection were shown to involve NF-kappaB activation and increased survivin production. In conclusion, our findings identify autocrine VEGF as an important mediator of the antiapoptotic effect of CD40 ligation, and thus provide new insights into CLL-cell rescue by CD154 in lymphoreticular tissues.

Measurement of absorbed doses near metal and dental material interfaces irradiated by x- and gamma-ray therapy beams

Soft-tissue damage adjacent to dental restorations is a deleterious side effect of radiation therapy which is associated with low-energy electron scatter from dental materials of high electron density. This study was designed to investigate the enhancement of dose to soft tissue (or water) close to high electron-density materials and to measure the detailed lateral and depth-dose profiles in soft-tissue-simulating polymer adjacent to planar interfaces of several higher atomic-number materials: 18-carat gold dental casting alloy; Ag-Hg dental amalgam alloy; Ni-Cr dental casting alloy; and natural human tooth structure. Interleaved stacks of calibrated thin radiochromic dosimeter films and tissue-simulating polymer were used for these measurements. Assemblies of these polymer-dosimeter stacks on both sides of the dental materials were irradiated in one fixed direction by collimated 60Co gamma-ray or 10 MV x-ray beams directed perpendicularly to the material interfaces. In another test, designed to simulate more closely therapeutic treatment conditions, a phantom constructed on both sides of a row of restored and unrestored whole teeth (restoration materials: gold alloy crown; Ni-Cr alloy crown; Ag-Hg mesial-occlusal-distal (MOD) amalgam filling; unrestored tooth) was irradiated in one fixed direction by the collimated photon beams. Results indicate that the dose-enhancement in 'tissue' is as great as a factor of 2 on the backscatter side adjacent to gold and a factor of 1.2 adjacent to tooth tissue, but is insignificant on the forward-scatter side because of the predominant effect of attenuation by the high-density, high atomic-number absorbing material.

Regulation of histamine H1 receptor coupling by dexamethasone in human cultured airway smooth muscle

1. The regulation of histamine-induced [3H]-inositol phosphate and intracellular calcium responses in human cultured airway smooth muscle cells was studied. 2. Histamine induced concentration-dependent [3H]-inositol phosphate formation (EC50 4 microM). This response was inhibited by a range of selective H1 receptor antagonists but not by the H2-selective antagonist, tiotidone or the H3 receptor-selective antagonist, thioperamide, indicating that an H1 receptor is involved in this response in human cultured airway smooth muscle cells. 3. Preincubation of human cultured airway smooth muscle cells with concentrations of dexamethasone > 10 nM for 22 h produced concentration-dependent inhibition of histamine-induced inositol phosphate formation. The maximum inhibition observed was 45% of the response in control cells. The inhibitory effect of dexamethasone was itself reversed by prior exposure to the glucocorticoid receptor antagonist, RU38486 (10 microM). Preincubation for 22 h with 1 microM dexamethasone produced inhibition of the inositol phosphate response to histamine to all concentrations of histamine inducing significant inositol phosphate formation in these cells. In contrast, the response to the G protein activator, NaF (0.1-20 mM) was unaltered by preincubation with dexamethasone. 4. Preincubation of human airway smooth muscle cells with 1 microM dexamethasone for time periods of < 6 h failed to inhibit histamine-induced inositol phosphate formation in human airway smooth muscle cells. 5. Histamine also induced concentration-dependent elevation of intracellular calcium levels in Fura 2-loaded human airway smooth muscle cells. This response was inhibited by preincubation with 1 microM dexamethasone. 6. We conclude that signal transduction through the H1 receptor in human airway smooth muscle is subject to regulation by dexamethasone and that this may in part account for the protective effect of dexamethasone against spasmogen-induced contractile responses in the airways.

Metal-polysiloxane shields for radiation therapy of maxillo-facial tumors

In the treatment of some head and neck lesions with high-intensity radiation (teletherapy), an essential procedure is the application of an individually customized shielding appliance, which is designed, modeled, and formed into a working extra- or intraoral stent for the purpose of sparing healthy tissues. The present state of the art is slow and technique intensive, which can add to patient discomfort and inconvenience during molding and fabrication. A new formulation is described, which offers speed and ease of forming a moldable composite stent especially for intraoral use. Interleaved stacks of calibrated thin radiochromic film strips and soft-tissue-simulating plastic (polystyrene) layers gave a means of mapping one- or two-dimensional profiles of dose distributions adjacent to the high-density shielding materials using a spectrophotometer equipped with a gel scanner or a scanning laser-beam microdensitometer. Tests using collimated gamma-ray beams from a 60Co teletherapy unit were made in order to measure the dose distribution near interfaces of tissue-simulating polymer and the composite stent material with and without mixtures of metals (Ag-Cu and Sn-Sb). These results show that quickly formed composites made of a flexible resin with high concentrations of powdered spherical metal alloys provide effective custom-designed shielding, and, with a thin overlayer of the resin without metal, a diminished back-scattered radiation dose to normal tissues. An example of a successful formulation is a mixture of 90% by weight Ag-Cu alloy powder in a vinyl polysiloxane resin. This material is a moldable putty which, upon polymerization, forms a rigid elastomeric material, providing a half-value layer of approximately 2.5 to 2.8 cm for a gamma-ray beam from a 60Co source.

High porous electrospun poly(ε-caprolactone)/gelatin/MgO scaffolds preseeded with endometrial stem cells promote tissue regeneration in full-thickness skin wounds: An in vivo study

In the current study, electrospun poly(ε-caprolactone)-gelatin (PCL-Gel) fibrous scaffolds containing magnesium oxide (MgO) particles and preseeded with human endometrial stem cells (hEnSCs) were developed to use as wound care material in skin tissue engineering applications. Electrospun fibers were fabricated using PCL-Gel (1:1 [wt/wt]) with different concentrations of MgO particles (1, 2, and 4 wt%). The fibrous scaffolds were evaluated regarding their microstructure, mechanical properties, surface wettability, and in vitro and in vivo performances. The full-thickness excisional wound model was used to evaluate the in vivo wound healing ability of the fabricated scaffolds. Our findings confirmed that the wounds covered with PCL-Gel fibrous scaffolds containing 2 wt% MgO and preseeded with hEnSCs have nearly 79% wound closure ability while sterile gauze showed 11% of wound size reduction. Our results can be employed for biomaterials aimed at the healing of full-thickness skin wounds.

Kinetic studies of aflatoxin B1-glutathione conjugate formation in liver and kidneys of adult and weanling rats

Aflatoxin B1(AFB1)-glutathione(GSH) conjugation is the major pathway for the detoxification of aflatoxin metabolites. This reaction is catalysed by GSH S-transferase (GST) and play a major role in modulation of AFB1 adduct formation to nuclear DNA. Changes recorded in hepatic GST activity during development of rats can alter the balance between AFB1-GSH conjugation and AFB1-DNA adduct formation. Measurment of cytosolic GST using 1-chloro-2,4-dinitrobenzene (CDNB) as the substrate showed that the enzyme activity is initially lower in weanling tissues as compared to that of adults. But nevertheless hepatic and renal cytosolic GST activity is increased significantly in growing rats pretreated with AFB1. Kinetic studies of AFB1-GSH conjugate formation in kidneys and livers of the two-age groups of rats treated with a single i.p. dose of AFB1 (400 microg/kg b.w.) revealed that at the end of 24 h of AFB1 administration the rate of the conjugate formation in kidneys of immature rats was approximately twice of that measured in adults. Age-related differences in the GST activity as well as AFB1-GSH conjugation was more pronounced in kidneys. The conjugate formation in kidneys of growing rats during 6-24 h following AFB1 administration shows that urinary excretion of aflatoxin metabolites is relatively rapid in growing rats. The major portion of the AFB1-GSH is formed in liver but contribution of the renal tissue to the formation of detoxification metabolites can not be ruled out. These data demonstrate that aflatoxin metabolites are eliminated more efficiently from kidneys of a growing rat. AFB1-induced GST induction in renal tissues of growing animals during 24 h of the carcinogen administration could be considered as an important mechanism for GSH conjugate formation and aflatoxin detoxification. Therefore GST induction in response to hepatotoxic drugs can confer resistance to young animals being exposed for the first time to such drugs. It is also worthmentioning that the GST activity measured before AFB1 administration does not reflect the rate of AFB1 detoxification via GSH conjugation.

Quantification of the selective retention of palladium octabutoxynaphthalocyanine, a potential photothermal drug, in mouse tissues

Palladium octabutoxynaphthalocyanine (PdNc(OBu)8) is a potential photothermal therapy (PTT) agent, absorbing strongly in the near-infrared region with no ability to induce photodynamic-type sensitisation (unlike many related napthalocyanines). We report here on the application of high pressure liquid chromatography (HPLC) with near-infrared absorption detection for the determination of the tissue accumulation and clearance of PdNc(OBu)8 in a tumour-bearing mouse model (Balb/c mice with EMT6 carcinoma tumour). Due to its insolubility in aqueous-based solvents, the drug was delivered intraperitoneally in a Cremophor-containing vehicle. Good selective accumulation of the drug into the tumour versus muscle or skin is observed, with the best combination of selectivity and tumour concentration occurring at 24-72 h after drug administration. Clearance times are quite long. Comparison with other similar drugs as reported in the literature indicates that the Cremophor-containing vehicle is likely in large part responsible for the observed pharmacokinetic behaviour. This drug shows potential for PTT and will be investigated further for therapy in this animal model.

Coronavirus disease 2019 and stroke in Iran: a case series and effects on stroke admissions

OBJECTIVE

The coronavirus disease 2019 pandemic has affected healthcare systems around the globe and massively impacted patients with various non-infectious, life-threatening conditions. Stroke is a major neurological disease contributing to death and disability worldwide, and is still an ongoing issue during the pandemic. Here we investigate the impact of the coronavirus disease 2019 outbreak on stroke manifestations, treatment courses, the outcome of stroke patients, and the hospitalization rate in a referral center for stroke management in Tehran, Iran.

METHODS

We extracted data regarding 31 stroke patients (10 patients with laboratory-confirmed coronavirus disease 2019) and compared the demographic and pathological characteristics of the patients with or without coronavirus disease 2019 infection. The association of demographic/pathological characteristics of stroke patients during the coronavirus disease 2019 pandemic and a corresponding period during the previous year (49 patients) and an earlier period during the same year as the pandemic (50 patients) was also evaluated.

RESULTS

The absolute number of admissions decreased about 40% during the coronavirus disease 2019 pandemic. Except for the stroke severity (P = 0.002), there were no significant changes in the demographic and pathological characteristics of the stroke patients during the three studied periods. A significantly higher mean of age (75.60 ± 9.54 versus 60.86 ± 18.45; P = 0.007), a significant difference in the type of stroke (P = 0.046), and significantly higher stroke severity (P = 0.024) were observed in stroke patients with coronavirus disease 2019 compared with those of stroke patients without coronavirus disease 2019. Treatment approaches, duration of hospitalization, and mortality rates did not differ significantly.

CONCLUSIONS

This report shows that the pandemic caused the number of acute stroke admissions to plummet compared to other periods. Although the pandemic did not affect the treatment plans and care of the patients, stroke cases with coronavirus disease 2019 had higher age, more large vessel ischemic stroke, and more severe stroke. Further studies are urgently needed to realize the probable interaction of the coronavirus disease 2019 pandemic and the neurologic disease.

MALDI-TOF MS analysis of a library of polymerizable cyclodextrin derivatives

Polymerizable cyclodextrin derivatives (PCDs) have been proposed as candidates for use in dental therapeutics (Bowen, 1996; Bowen and Reed, 1997). Here, PCD "libraries" were synthesized by quasi-random reactions of 6 moles of methacrylic anhydride plus 6 moles of cyclic glutaric anhydride per mole of beta-cyclodextrin (BCD) in solution. BCD has 21 reactive sites on each of its molecules. These proportions were based on probability calculations, which predicted that the products should have a minimum of 2 polymerizable substituents and acidic ligand groups on practically every one of the diverse product molecules. Matrix-assisted laser desorption/ionization (MALDI) time of flight (TOF) mass spectrometry (MS) gave valuable information regarding the masses of molecular ions representing the molecules that made up the PCD libraries. For the MALDI-TOF MS analyses, small samples were analyzed by the successive application of 3 solutions to the sample holder: the matrix in acetone, the products in water, and sodium trifluoroacetate in water. The resulting spectra had > 40 envelopes of mass peaks above background. The ionic-abundance peak heights had quasi-Gaussian configurations, with central peaks having masses in the neighborhood of 2000 g/mol (Daltons). Regardless of structural permutations within each peak, the range of these peaks was between about 1500 g/mol and 2900 g/mol. This range of masses was in accord with, but perhaps somewhat more narrow than, that predicted by the statistical method, which was based on equal reactivity of all hydroxyl groups. Analysis by MALDI-TOF MS gave valuable data regarding the masses, structures, and characteristics of the products formed and provided unanticipated information to facilitate improvements in future PCD syntheses.

New method for shielding electron beams used for head and neck cancer treatment

Shields and stents of metals with high atomic number, which are custom cast in molds from the melt, are the materials most widely used to protect surrounding tissues during treatment of skin or oral lesions with therapeutic electron beams. An improved fabrication method is to mix a polysiloxane-metal composite, which is readily cast at room temperature by combining a metal-powder/polysiloxane resin mixture with a hardening catalyst. The purpose of the present study is to compare the shielding effectiveness of two different metal-polysiloxane composites with that of conventional cast Lipowitz metal (50.1% Bi, 26.6% Pb, 13.3% Sn, 10% Cd). Also, a 2(3) factorial experiment was run to investigate the effects and interactions of metal particle size (20-microns vs 100-microns diameter), the atomic weight of the metal (304 stainless steel vs 70% Ag, 30% Cu alloy), and the presence or absence of a layer of unfilled polymer added to the forward-scatter side of the shield. The composites of different thicknesses were made by blending 90% (w/w) metal powder separately with 10% polysiloxane base and catalyst. A thin GafChromic dosimeter film was placed between the shielding material and a polystyrene base to measure the radiation shielding effect of composite disc samples irradiated with a 6-MeV electron beam normal to the flat surface of the disc. The results show that composite shields with the metal of higher atomic weight and density (Ag-Cu) combined with an additional unfilled layer are more effective than the stainless-steel composite with a similar additional unfilled layer, in terms of diminishing the dose at the surface of the polystyrene backing material.(ABSTRACT TRUNCATED AT 250 WORDS)

Glutathione-S-transferase subtypes α and π as a tool to predict and monitor graft failure or regeneration in a pilot study of living donor liver transplantation

Objective

Glutathione-S-Transferase (GST) subtype α and π are differentially expressed in adult liver tissue. Objective of the study was if GST α and p may serve as predictive markers for liver surgery, especially transplantations.

Methods

13 patients receiving living donor liver transplantation (LDLT) and their corresponding donors were analyzed for standard serum parameters (ALT, AST, gGT, bilirubin) as well as GST-α and -π before LDLT and daily for 10 days after LDLT. Patients (R) and donors (D) were grouped according to graft loss (R1/D1) or positive outcome (R2/D2) and above named serum parameters were compared between the groups.

Results

R1 showed significantly increased GST-α and significantly lower GST-π levels than R2 patients or the donors. There was a positive correlation between GST-α and ALT, AST as well as bilirubin and a negative correlation to γGT. However, γGT correlated positively with GST-π. Graft failure was associated with combined low GST-π levels in donors and their recipients before living donor liver transplantation.

Conclusion

Our data suggest that high GST-α serum levels reflect ongoing liver damage while GST-P indicates the capacity and process of liver regeneration. Additionally, GST-π may be useful as marker for optimizing donor and recipient pairs in living donor liver transplantation.

New surface-active comonomer for adhesive bonding

Previous studies have indicated that chemical and physical characteristics of aromatic amines can be influenced by the nature of their substituents. The experimental question examined in the present study relates to the effects of replacing specific hydrogen atoms with methyl groups in a surface-active comonomer utilized in adhesive bonding protocols. N-2-propionic acid-N-3-(2-hydroxy-1-methacryloxy)propyl-3,5-dimethylaniline sodium salt (N35A) was synthesized by an addition reaction of glycidyl methacrylate with the sodium salt of N-reaction of glycidyl methacrylate with the sodium salt of N-(3,5-dimethylphenyl)alanine, which was formed by alkaline hydrolysis of ethyl-N-(3,5-dimethylphenyl)alanate that was prepared by condensation of ethyl-2-bromopropionate with 3,5-dimethylaniline. 1H and 13C NMR spectra and analysis by mass spectroscopy were consistent with N35A after it had been recrystallized from acetone. Color stability and adhesion-promoting capability of N35A were compared with those of N-2-acetic acid-N-3-(2-hydroxy-1-methacryloxy)propyl-4-methylanaline sodium salt (Na-NTG-GMA), the latter being widely used in commercial bonding formulations. Both N35A and Na-NTG-GMA polymerized within a few minutes at 23 degrees C when dissolved in aliquots from a stock solution containing benzene 85 wt%, ethanol 14 wt%, and benzoyl peroxide 1.0 wt%; but with each at 0.018 molal concentration, the N35A suspension was more color-stable than that of the Na-NTG-GMA. In the protocol used, shear bond strengths of a hybrid composite to human dentin with N35A were 30.2 MPa, SD = 7.5 MPa, and with Na-NTG-GMA, 29.7 MPa, SD = 11.8 MPa(n = 7 each; t test, p = 0.93).

The effect of catalyst structure on the synthesis of a dental restorative monomer

The addition product of 2-hydroxyethyl methacrylate (HEMA) and pyromellitic dianhydride (PMDA), known as PMDM, is a mixture of two structural isomers. The para PMDM isomer--currently used in mediating adhesive bonding of restorative materials to hard tooth tissues--is a crystalline solid. The meta isomer is a liquid. In the synthesis of PMDM, the para isomer, which can be purified by crystallization, is usually present to the extent of only 50% of the product mixture. The effect of the amine catalyst structure was studied relative to its role in increasing the yield of the para isomer, either by a reduction in the amount of the meta isomer or by an increase in the extent of overall reaction. The chemical structure of the amine catalyst had an important role in the synthesis of PMDM and influenced the ratio of the isomers. Among aliphatic amines, especially noteworthy as catalysts that gave excellent yields of the para isomer in high purity were N,N-di-isopropyl-ethylamine and hexamethylenetetramine.

Enhanced sciatic nerve regeneration with fibrin scaffold containing human endometrial stem cells and insulin encapsulated chitosan particles: An in vivo study

BACKGROUND

Based on recent advances in tissue engineering and stem cell therapy in nervous system diseases treatments, this study aimed to investigate sciatic nerve regeneration using human endometrial stem cells (hEnSCs) encapsulated fibrin gel containing chitosan nanoparticle loaded by insulin (Ins-CPs). Stem cells and also Insulin (Ins), which is a strong signaling molecule in peripheral nerve regeneration, play an important role in neural tissue engineering.

METHODS

The fibrin hydrogel scaffold containing insulin loaded chitosan particles was synthesized and characterized. Release profiles of insulin from hydrogel was determined through UV-visible spectroscopy. Also, human endometrial stem cells encapsulated in hydrogel and its cell biocompatibility were assigned. Furthermore, the sciatic nerve crush injury was carried out and prepared fibrin gel was injected at the crush injury site by an 18-gage needle. Eight and twelve weeks later, the recovery of motor and sensory function and histopathological evaluation were assessed.

RESULTS

The in vitro experiments showed that the insulin can promote hEnSCs proliferation within a certain concentration range. Animals' treatment confirmed that developed fibrin gel containing Ins-CPs and hEnSCs significantly improves motor function and sensory recovery. Hematoxylin and Eosin (H&E) images provided from cross-sectional and, longitudinal-sections of the harvested regenerative nerve showed that regenerative nerve fibers had been formed and accompanied with new blood vessels in the fibrin/insulin/hEnSCs group.

CONCLUSION

Our results demonstrated that the prepared hydrogel scaffolds containing insulin nanoparticles and hEnSCs could be considered as a potential biomaterial aimed at regeneration of sciatic nerves.

Simultaneous impact of atorvastatin and mesenchymal stem cells for glioblastoma multiform suppression in rat glioblastoma multiform model

Glioblastoma multiform (GBM) is known as an aggressive glial neoplasm. Recently incorporation of mesenchymal stem cells with anti-tumor drugs have been used due to lack of immunological responses and their easy accessibility. In this study, we have investigated the anti-proliferative and apoptotic activity of atorvastatin (Ator) in combination of mesenchymal stem cells (MSCs) on GBM cells in vitro and in vivo. The MSCs isolated from rats and characterized for their multi-potency features. The anti-proliferative and migration inhibition of Ator and MSCs were evaluated by MTT and scratch migration assays. The annexin/PI percentage and cell cycle arrest of treated C6 cells were evaluated until 72 h incubation. The animal model was established via injection of C6 cells in the brain of rats and subsequent injection of Ator each 3 days and single injection of MSCs until 12 days. The growth rate, migrational phenotype and cell cycle progression of C6 cells decreased and inhibited by the interplay of different factors in the presence of Ator and MSCs. The effect of Ator and MSCs on animal models displayed a significant reduction in tumor size and weight. Furthermore, histopathology evaluation proved low hypercellularity and mitosis index as well as mild invasive tumor cells for perivascular cuffing without pseudopalisading necrosis and small delicate vessels in Ator + MSCs condition. In summary, Ator and MSCs delivery to GBM model provides an effective strategy for targeted therapy of brain tumor.

Hydroxyl radical induced cross-linking between phenylalanine and 2-deoxyribose

Hydroxy radicals induce cross-linking between phenylalanine (Phe) and 2-deoxyribose (dR) via formation of corresponding free radical intermediates. The cross-linked products were separated and identified by capillary gas chromatography-mass spectrometry. When phenylalanine and 2-deoxyribose radicals were generated in a 1:1 ratio, the predominant interaction was between Phe and dR radicals while the Phe-Phe and dR-dR cross-links were less abundant. The newly discovered cross-link between 2-deoxyribose and phenylalanine may serve as a model for radiation or free radical induced cross-linking between DNA and proteins and in general between sugar moieties and amino acids.

Decrease in erythrocyte:plasma lithium ratio by concurrent administration of psychotropic drugs and lithium in mice

1. Previous studies paying attention to concurrent use of lithium (Li+) with a neuroleptic were not done under constant and controlled conditions. We were therefore encouraged to do a prospectively controlled study, presuming constant relevant factors, on concomitant use of Li+ with neuroleptic as well as other psychotropic agents. 2. The effects of concurrent administration of chlorpromazine, haloperidol, imipramine and carbamazepine with Li+ on the erythrocyte:plasma Li+ ratio and the intraerythrocyte Li+ concentration were studied in mice by using a new, direct method of measuring erythrocyte Li+ concentration. 3. All of the foregoing agents with the exception of carbamazepine were observed to significantly decrease the Li+ ratio. 4. Lack of any significant effect by carbamazepine on Li+ transport may be an indication of this drug's efficacy as a supplement in Li+ therapy of bipolar affective disorders. 5. The decrease in Li+ ratio observed with chlorpromazine, haloperidol and imipramine may be explained through the mechanism by which these drugs stabilize the cell membrane and consequently affect Li+ transport in erythrocytes. 6. Moreover, our study proves that, although the Li(+)-sodium countertransport mechanism does not exist in mice, the same interaction between Li+ and other psychotropic drugs is seen. It can be concluded that such interaction is not mediated through Li(+)-sodium countertransport. 7. It is suggested that, with concurrent use of a psychotropic drug and Li+, the amount of intraerythrocyte Li+ concentration be measured, instead of relying on the plasma Li+ concentration alone.

Effect of videotape for home instruction on the quality of life of tracheostomy patients: a randomized clinical trial

Background: Nowadays, some of the patients, such as the patients with tracheostomy are taken care of at home. The quality of life of these cases may decrease due to the appearance of changes, limitations caused by tracheostomy and improper care. Objectives: This research was performed in order to discover the effect of videotape for home instruction on the quality of life of tracheostomy cases. Patients and Procedure: A quasi-empirical research was carried out on 80 cases by a tracheotomy in Amir Elm Hospital and the Imam Khomeini Medical Center in Tehran. Patients were randomized into two teams of invasion and check through the randomized block design method. At the time of discharge and after a routine training from the clinical staff, the two groups completed a questionnaire regarding the demographic information and the sf-36 quality of life. Then, the intervention team was given a CD containing the routine training for patient care to watch at home. After two months, the participants completed the sf-36 questionnaires again, and the data were entered into SPSS version 20. The information was investigated by using the statistical tests. Findings: The statistical investigation demonstrated that the comparison between the two groups after the intervention in the overall quality of life (p = 0.003) and all the concepts included: the physical role (p = 0.02), the mental role (p = 0.01), energy and fatigue (p = 0.03), motion health (p = 0.005), social functioning (p = 0.06), disorder (p = 0. 001), common health percentage (p = 0.002) and physical functioning (p = 0.001) in the arbitration team, being higher than in the check one. Conclusion: Using the videotape education additionally to routine care has a significant effect on the improvement of the quality of life in these patients. Therefore, the use of this method is recommended as a complementary program for tracheostomy patients.

The Impact of Bolus Rheology on Physiological Swallowing Parameters Derived by Pharyngeal High-Resolution Manometry Impedance

BACKGROUND

The shear rheology of ingested fluids influences their pharyngo-esophageal transit during deglutition. Thus, swallowed fluids elicit differing physiological responses due to their shear-thinning profile.

METHODS

Two hydrocolloid fluids, xanthan gum (XG) and sodium carboxymethylcellulose gum (CMC), were compared in 10 healthy adults (mean age 39 years). Manometry swallowing assessments were performed using an 8-French catheter. Swallows were analyzed using the Swallow Gateway web application (www.swallowgateway.com). Grouped data were analyzed by a mixed statistical model. The coefficient of determination (r2) assessed the relationship between measures and bolus viscosity (SI units, mPa.s) at shear rates of 1-1000 s-1.

KEY RESULTS

Rheology confirmed that the thickened fluids had similar viscosities at 50 s-1 shear rate (XG IDDSI Level-1, 2, and 3 respectively, 74.3, 161.2, and 399.6 mPa.s vs. CMC Level-1, 2, and 3 respectively 78.0, 176.5, and 429.2 mPa.s). However, at 300 s-1 shear, CMC-thickened fluids exhibited approximately double the viscosity (XG Level-1, 2, and 3 respectively 19.5, 34.4, and 84.8 mPa.s vs. CMC Level-1, 2, and 3 respectively, 41.3, 80.8, and 160.2 mPa.s). In vivo swallows of CMC, when compared to XG, showed evidence of greater flow resistance, such as increased intrabolus pressure (p < 0.01) and UES Integrated Relaxation Pressure (UESIRP, p < 0.01) and shorter UES Relaxation Time (p < 0.05) and Bolus Presence Time (p < 0.001). The apparent fluid viscosity (mPa.s) correlated most significantly with increasing UESIRP (r2 0.69 at 50 s-1 and r2 0.97 at 300 s-1, p < 0.05).

CONCLUSION

Fluids with divergent shear viscosities demonstrated differences in pharyngeal function. These physiological responses were linked to the shear viscosity and not the IDDSI level.

Characteristics of TPT initiation and completion among people living with HIV

BACKGROUND

TB preventive treatment (TPT) reduces morbidity and mortality among people living with HIV (PLHIV). Despite the successful scale-up of TPT in Malawi, monitoring and evaluation have been suboptimal. We utilized the Malawi Population-Based HIV Impact Assessment (MPHIA) 2020-2021 survey data to estimate TPT uptake and completion among self-reported HIV-positive persons.

METHODS

We estimated the proportion of HIV-positive respondents who had ever undergone TPT, and determined the percentage of those currently on TPT who had completed more than 6 months of treatment. Bivariate and multivariable logistic regression were performed to calculate the odds ratios for factors associated with ever-taking TPT. All variables were self-reported, and the analysis was weighted and accounted for in the survey design.

RESULTS

Of the HIV+ respondents, 38.8% (95% CI 36.4-41.3) had ever taken TPT. The adjusted odds of ever taking TPT were 8.0 and 5.2 times as high in the Central and Southern regions, respectively, compared to the Northern region; 1.9 times higher among those in the highest wealth quintile, and 2.1 times higher for those on antiretroviral therapy >10 years. Of those currently taking TPT, 56.2% completed >6 months of TPT.

CONCLUSION

These results suggest low TPT uptake and >6 months' completion rates among self-reported HIV+ persons. Initiatives to create demand and strengthen adherence would improve TPT uptake.