Preclinical Study of 68Ga-DOTATOC: Biodistribution Assessment in Syrian Rats and Evaluation of Absorbed Dose in Human Organs

OBJECTIVES

Gallium-68 DOTA-DPhe1-Tyr3-Octreotide (68Ga-DOTATOC) has been applied by several European centers for the treatment of a variety of human malignancies. Nevertheless, definitive dosimetric data are yet unavailable. According to the Society of Nuclear Medicine and Molecular Imaging, researchers are investigating the safety and efficacy of this radiotracer to meet Food and Drug Administration requirements. The aim of this study was to introduce the optimized procedure for 68Ga-DOTATOC preparation, using a novel germanium-68 (68Ge)/68Ga generator in Iran and evaluate the absorbed doses in numerous organs with high accuracy.

METHODS

The optimized conditions for preparing the radiolabeled complex were determined via several experiments by changing the ligand concentration, pH, temperature and incubation time. Radiochemical purity of the complex was assessed, using high-performance liquid chromatography and instant thin-layer chromatography. The absorbed dose of human organs was evaluated, based on biodistribution studies on Syrian rats via Radiation Absorbed Dose Assessment Resource Method.

RESULTS

68Ga-DOTATOC was prepared with radiochemical purity of >98% and specific activity of 39.6 MBq/nmol. The complex demonstrated great stability at room temperature and in human serum at 37°C at least two hours after preparation. Significant uptake was observed in somatostatin receptor-positive tissues such as pancreatic and adrenal tissues (12.83 %ID/g and 0.91 %ID/g, respectively). Dose estimations in human organs showed that the pancreas, kidneys and adrenal glands received the maximum absorbed doses (0.105, 0.074 and 0.010 mGy/MBq, respectively). Also, the effective absorbed dose was estimated at 0.026 mSv/MBq for 68Ga-DOTATOC.

CONCLUSION

The obtained results showed that 68Ga-DOTATOC can be considered as an effective agent for clinical PET imaging in Iran.

Template-Directed Directionally Solidified 3D Mesostructured AgCl-KCl Eutectic Photonic Crystals

3D mesostructured AgCl-KCl photonic crystals emerge from colloidal templating of eutectic solidification. Solvent removal of the KCl phase results in a mesostructured AgCl inverse opal. The 3D-template-induced confinement leads to the emergence of a complex microstructure. The 3D mesostructured eutectic photonic crystals have a large stop band ranging from the near-infrared to the visible tuned by the processing.

Comparative Study on the Effects of Ceftriaxone and Monocytes on Recovery after Spinal Cord Injury in Rat

PURPOSE

Comparison between the efficacy of ceftriaxone and monocytes on improvement of neuron protection and functional recovery after spinal cord injury (SCI) in rat.

METHODS

Rats were randomly divided into three groups of ten. Spinal cord injury was performed on rats under general anesthesia using the weight dropping method. Ceftriaxone was injected intraperitoneally 200 mg/kg/day for seven days after SCI. Monocytes were injected 2 × 105 cells 4 days after SCI. Hind limb motor function was assessed using the Basso, Beattie and Bresnahan (BBB) scale. Corticospinal tract (CST) axons were traced by injection of biotin dextran amine (BDA) into the sensorimotor cortex.

RESULTS

There were statistically significant differences in BBB scores in ceftriaxone in comparison to both monocytes receiving and control groups. On the other hand there were statistically significant differences in axon counting in both ceftriaxone and monocytes receiving groups in comparison to control group.

CONCLUSION

Our findings suggest that ceftriaxone improves functional recovery more effective than monocytes in rats after SCI. These results are from an experimental model and validation is required for further investigation.

Design and synthesis of pH-sensitive polyamino-ester magneto-dendrimers: Surface functional groups effect on viability of human prostate carcinoma cell lines DU145

Novel pH-sensitive, biocompatible and biodegradable magneto-dendrimers with OH and/or NH2 functional groups based on poly amino-ester were synthesized for delivery of anti-cancer drugs. Magnetite nanoparticles (MNPs) were synthesized by the co-precipitation method and their surfaces were modified by 3-aminopropyl triethoxysilane. The first and second generations of the magneto-dendrimer with hydroxyl end groups were produced by sequential acrylation and Michael addition reactions using the required amounts of acryloyl chloride and diethanolamine, respectively. The dendrimer containing amino functional surface groups up to second generation was synthesized by the same method using the necessary amounts of acryloyl chloride and ethylenediamine. These dendrimers were fully characterized by the Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), dynamic light scattering (DLS) and zeta potential analysis, vibrating-sample magnetometer (VSM), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). In-vitro release profiles of the drug-loaded magnetic nanoparticles and their cytotoxicity assay were investigated at two pHs (7.4 and 5.8). The hydrolytic degradation behavior of magneto-dendrimers was evaluated in PBS buffer. Our research suggests that magneto-dendrimers having amine or hydroxyl functional groups could be considered as the suitable nanocarriers for therapy applications.

Detecting the frequency of aminoglycoside modifying enzyme encoding genes among clinical isolates of methicillin-resistant Staphylococcus aureus

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) plays an important role in causing many serious nosocomial infections. In this study, the antimicrobial susceptibility and the frequency of aminoglycoside modifying enzyme encoding genes among clinical isolates of methicillin-resistant Staphylococcus aureus was investigated from two university hospitals of Zanjan province of Iran.

METHODS

In this study, the antimicrobial susceptibility of MRSA isolates to various antibiotics was investigated by the disk diffusion method. Multiplex PCR assays were used for the determination of aminoglycoside modifying enzyme (AME) genes and staphylococcal cassette chromosome mec (SCCmec) types in MRSA strains.

RESULTS

All 58 MRSA isolates were sensitive to vancomycin. Resistance to penicillin G, oxacilin, gentamicin, erythromycin, clindamycin, kanamycin, and tobramycin was found in 96.4%, 98.3%, 51.7%, 53.4%, 55.2%, 62% and 58.6% of the isolates, respectively. The most prevalent AME genes were aac(6')/aph(2'') (48.3 %) followed by ant(4)-Ia (24%). The aph(3')-Ia gene was the least frequent AME gene among MRSA isolates (19%). Of the 58 tested MRSA isolates, 5 (8.6%) were harboured SCCmec type I, 11 (19%) SCCmec type II, 20 (34.5%) SCCmec type III, 17 (29.3%) SCCmec type IVa, 1 (1.7%) SCCmec type IVb, 2 (3.4%) SCCmec type IVc, 11 (19%) SCCmec type IVd, and, 18 (31%) SCCmec type V. Nineteen isolates were not typeable.

CONCLUSION

In conclusion, the aac (6')/aph (2'') was the most common aminoglycoside modifying enzyme gene and SCCmec type II and V were the most frequent types detected in hospital isolates, respectively.

Isolation and characterization of Borrelia burgdorferi strains from Ixodes ricinus ticks in the southern England

Introduction: Lyme disease is a bacterial infection caused by the spiral-shaped bacterium Borrelia burgdorferi. We investigated the presence and prevalence of Borrelia species in ticks from the southern England.

Methods: One hundred fifty-five cases (103 adult and 52 nymphal ticks) were collected from animal carcases. The midguts were removed, cultured in Barbour/Stoenner/Kelly II (BSK-II) and Barbour/ Stoenner/Kelly F (BSK-F) media and examined by IF, dark-field microscopy, and nested PCR.

Results: From a total 155 cultured ticks, two showed evidence of spirochetes and denoted as SO-1 and SO-2 strains. The availability of these two isolates enabled their antigenic characterization with SDS-PAGE and western blotting and comparison with two standard isolates. These studies identified six protein antigens with molecular weights of 18, 30, 39, 47, 60 and 88 kDa with particular promise for detecting specific immune responses to B. burgdorferi infection including Lyme disease. We also investigated the effect of repeated subculture on the antigenic pattern of UK isolate of B. burgdorferi.

Conclusion: As a result of this study, antigenic differences have been seen between the UK isolates and the foreign isolates used as laboratory standards.

An ultra-sensitive impedimetric immunosensor for detection of the serum oncomarker CA-125 in ovarian cancer patients

Effective treatment of ovarian cancer depends upon the early detection of the malignancy. Here, we report on the development of a new nanostructured immunosensor for early detection of cancer antigen 125 (CA-125). A gold electrode was modified with mercaptopropionic acid (MPA), and then consecutively conjugated with silica coated gold nanoparticles (AuNP@SiO2), CdSe quantum dots (QDs) and anti-CA-125 monoclonal antibody (mAb). The engineered MPA|AuNP@SiO2|QD|mAb immunosensor was characterised using transmission electron microscopy (TEM), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Successive conjugation of AuNP@SiO2, CdSe QD and anti-CA-125 mAb onto the gold electrode resulted in sensitive detection of CA-125 with a limit of detection (LOD) of 0.0016 U mL(-1) and a linear detection range (LDR) of 0-0.1 U mL(-1). Based on the high sensitivity and specificity of the immunosensor, we propose this highly stable and reproducible biosensor for the early detection of CA-125.

Artemia salina as a model organism in toxicity assessment of nanoparticles

BACKGROUND

Because of expanding presence of nanomaterials, there has been an increase in the exposure of humans to nanoparticles that is why nanotoxicology studies are important. A number of studies on the effects of nanomatrials in in vitro and in vivo systems have been published. Currently cytotoxicity of different nanoparticles is assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on different cell lines to determine cell viability, a tedious and expensive method. The aim of this study was to evaluate the Artemia salina test in comparison with the MTT assay in the assessment of cytotoxicity of nanostructures because the former method is more rapid and convenient and less expensive.

METHODS

At the first stage, toxicity of different nanoparticles with different concentrations (1.56-400 μg/mL) was measured by means of the brine shrimp lethality test. At the second stage, the effect of nanoparticles on the viability of the L929 cell line was assessed using the MTT assay. Experiments were conducted with each concentration in triplicate.

RESULTS

The results obtained from both tests (A. salina test and MTT assay) did not have statistically significant differences (P>0.05).

CONCLUSIONS

These findings suggest that the A. salina test may expedite toxicity experiments and decrease costs, and therefore, may be considered an alternative to the in vitro cell culture assay.

Highly cadmium tolerant fungi: their tolerance and removal potential

BACKGROUND

Soil and effluent of lead and zinc industries contain high concentration of cadmium. The present study was conducted to isolate tolerant fungal strains from cadmium -polluted sites in Zanjan province, Iran.

METHODS

Cadmium tolerance and bioremediation capacity of seven isolates including Aspergilus versicolor, Aspergillus fumigatus, Paecilomyces sp.9, Paecilomyces sp.G, Terichoderma sp, Microsporum sp,Cladosporium sp were determined.

RESULTS

Minimum inhibitory concentration values among 1,000-4,000 mg l-(1)proved great ability of isolated strains to survive in cadmium polluted environments. The most tolerant fungi, Aspergilus versicolor, showed tolerance index of 0.8 in 100 mg l-(1) cadmium agar media. Fungal resistance against cadmium is depended directly on strain's biological function. A. versicolor was found to bioaccumulate over7 mg of cadmium per 1 g of mycelium, followed by 5.878, 5.243, and 5.075, 4.557 by Paecilomyces sp, Aspergilus fumigatus, Microsporum sp and Terichoderma sp, respectively.

CONCLUSION

It can be noted that tolerance of the strains appears to be independent from bioaccumulation capacity. Finally, the results indicated that A. versicolor could be a prospective candidate for bioremediation processes.

Ultrasonics in isocyanide-based multicomponent reactions: a new, efficient and fast method for the synthesis of fully substituted 1,3,4-oxadiazole derivatives under ultrasound irradiation

A fast and convenient approach to the synthesis of fully substituted 1,3,4-oxadiazoles via three-component reaction of aromatic carboxylic acids, acenaphthoquinone, and (N-isocyanimino)triphenylphosphorane under ultrasound irradiation is described. Furthermore, a series of compounds were synthesized and characterized by melting point, IR, NMR and MS. Utilization of easy reaction conditions, very high to excellent yields, and short reaction times makes this manipulation potentially very useful.

Effect of nanosilver on thermal and mechanical properties of acrylic base complete dentures

OBJECTIVE

Polymethyl methacrylate (PMMA), widely used as a prosthodontic base, has many disadvantages, including a high thermal expansion coefficient and low thermal conductivity, a low elasticity coefficient, low impact strength and low resistance to fatigue. This study aimed to make an in vitro comparison of the thermal conductivity, compressive strength, and tensile strength of the acrylic base of complete dentures with those of acrylic reinforced with nanosilver.

MATERIALS AND METHODS

For this study, 36 specimens were prepared. The specimens were divided into three groups of 12; which were further divided into two subgroups of control (unmodified PMMA) and test (PMMA mixed with 5 weight% nanosilver).The results were analysed by Independent t-test.

RESULTS

This study showed that the mean thermal conductivity and compressive strength of PMMA reinforced with nanosilver were significantly higher than the unmodified PMMA (P<0.05), while the tensile strength decreased significantly after the incorporation of nanosilver (P<0.05).

CONCLUSION

Considering our results suggesting the favorable effect of silver nanoparticles on improving the thermal conductivity and compressive strength of PMMA, use of this material in the palatal area of maxillary acrylic resin dentures is recommended.

Molecular detection of Brucella species in patients suspicious of Brucellosis from Zanjan, Iran

Brucella is an intracellular pathogen capable of infecting animals and humans. The aim of this study was to identify Brucella spp in sera of high risk individuals by a polymerase chain reaction (PCR)-based method. A total of 180 patients suspected to have Brucellosis were examined by serological tests. To establish a PCR protocol for diagnosis of active brucellosis, DNA was extracted from the serum samples by using a commercial kit. PCR amplification was done for detection of Brocella DNA using BCSP31 target gene and IS711 locus. The PCR assay showed that an amplicon of 223 bp was obtained in 73.8% (133/180) of the tested sera using primers (B4/B5) derived from a gene encoding the 31-kDa Brucella abortus antigen. In another PCR, an amplicon of 498 bp was obtained in 63.8% (115/180) of the samples using Brucella abortus-specific primers derived from a locus adjacent to the 3'-end of IS711, and also an amplicon of 731 bp was produced in 4.4% (8/180) of the tested samples using Brucella melitensis-specific primers. When the Wright method was used as a gold standard, the sensitivity and specificity of the PCR technique for genus identification were found to be 96 and 80.7%, respectively. However, the sensitivity value obtained with the species-specific PCR method was 82%, and specificity was similar to that previous reported. This is the first report of a high frequency of Brucella abortus in patients suspicious of Brucellosis from the Zanjan province.