Recent advances in targeting malaria with nanotechnology-based drug carriers

Malaria, as one of the most common human infectious diseases, remains the greatest global health concern, since approximately 3.5 billion people around the world, especially those in subtropical areas, are at the risk of being infected by malaria. Due to the emergence and spread of drug resistance to the current antimalarials, malaria-related mortality and incidence rates have recently increased. To overcome the aforementioned obstacles, nano-vehicles based on biodegradable, natural, and non-toxic polymers have been developed. Accordingly, these systems are considered as a potential drug vehicle, which due to their unique properties such as the excellent safety profile, good biocompatibility, tunable structure, diversity, and the presence of functional groups within the polymer structure, could facilitate covalent attachment of targeting moieties and antimalarials to the polymeric nano-vehicles. In this review, we highlighted some recent developments of liposomes as unique nanoscale drug delivery vehicles and several polymeric nanovehicles, including hydrogels, dendrimers, self-assembled micelles, and polymer-drug conjugates for the effective delivery of antimalarials.

Radiomics for classification of bone mineral loss: A machine learning study

PURPOSE

The purpose of this study was to develop predictive models to classify osteoporosis, osteopenia and normal patients using radiomics and machine learning approaches.

MATERIALS AND METHODS

A total of 147 patients were included in this retrospective single-center study. There were 12 men and 135 women with a mean age of 56.88±10.6 (SD) years (range: 28-87 years). For each patient, seven regions including four lumbar and three femoral including trochanteric, intertrochanteric and neck were segmented on bone mineral densitometry images and 54 texture features were extracted from the regions. The performance of four feature selection methods, including classifier attribute evaluation (CLAE), one rule attribute evaluation (ORAE), gain ratio attribute evaluation (GRAE) and principal components analysis (PRCA) along with four classification methods, including random forest (RF), random committee (RC), K-nearest neighbor (KN) and logit-boost (LB) were evaluated. Four classification categories, including osteopenia vs. normal, osteoporosis vs. normal, osteopenia vs. osteoporosis and osteoporosis+osteopenia vs. osteoporosis were examined for the defined seven regions. The classification model performances were evaluated using the area under the receiver operator characteristic curve (AUC).

RESULTS

The AUC values ranged from 0.50 to 0.78. The combination of methods RF+CLAE, RF+ORAE and RC+ORAE yielded highest performance (AUC=0.78) in discriminating between osteoporosis and normal state in the trochanteric region. The combinations of RF+PRCA and LB+PRCA had the highest performance (AUC=0.76) in discriminating between osteoporosis and normal state in the neck region.

CONCLUSION

The machine learning radiomic approach can be considered as a new method for bone mineral deficiency disease classification using bone mineral densitometry image features.

Radiation Exposure and Bell's Palsy: A Hypothetical Association

Bell's palsy is an idiopathic peripheral nerve palsy involving the facial nerve. It accounts for 60 to 75% of all cases of unilateral facial paralysis. The main mechanisms to induce BP remain unclear, but infection, ischemic condition and immunodeficiency may contribute to the development of Bell's palsy. Accumulating evidence has shown several factors can trigger the reactivation of latent HSV including psychological stressors, physical stressors and immunosuppression. Ionization and non-ionization radiations are of importance of physical stressors. Some data have shown radiation can reactivate HSVs. Based on preliminary studies showing radiation reactivation of HSVs, we aimed to hypothesize radiation (in both forms of ionization and non-ionization) may cause Bell's palsy. In the future, the role of radiotherapy, radiofrequency radiation from mobile phones and wireless devices in HSV reactivation and Bell's palsy should be investigated.

New physical approaches to treat cancer stem cells: a review

Cancer stem cells (CSCs) have been identified as the main center of tumor therapeutic resistance. They are highly resistant against current cancer therapy approaches particularly radiation therapy (RT). Recently, a wide spectrum of physical methods has been proposed to treat CSCs, including high energetic particles, hyperthermia (HT), nanoparticles (NPs) and combination of these approaches. In this review article, the importance and benefits of the physical CSCs therapy methods such as nanomaterial-based heat treatments and particle therapy will be highlighted.

Combination of H120 and 1/96 avian infectious bronchitis virus vaccine strains protect chickens against challenge with IS/1494/06 (variant 2)-like infectious bronchitis virus

Avian infectious bronchitis (IB) is a worldwide chicken disease, caused by avian infectious bronchitis virus (IBV) which infects all commercial poultry lines. The present study was done to evaluate protection caused by two different serotype vaccines (Massachusetts and 793/B) in order to evaluate protection against challenge with IS/1494/06-like virus (variant 2-like virus), which is prevalent in the Middle East. SPF chickens were divided into four groups (n = 20). First and second group as negative control group and non-vaccinated-challenged group received no vaccine. Groups 3 and 4 received H120-H120 and H120-1/96 IBV vaccine strains at the 1st and 14th day, respectively. Twenty one days after last vaccination, non-vaccinated-challenged group and vaccinated group were challenged using variant 2-like IBV. Serum samples were collected before challenge to measure humoral immune response of chickens. Five days after challenge, the tissue samples from the trachea, lungs and kidneys were taken to evaluate cilliary activity, viral load (quantitative real-time RT-PCR), and histopathological evaluation. Clinical sign scores were also recorded after challenge. Overall, the results showed a protective efficacy of the used vaccination program. Best cross protection (69.2%) was obtained in the H120-1/96 vaccinated group. Virus replication of the challenged virus in H120-1/96 group compared with H120-H120 group showed a significant reduction of viral load in trachea (1.5×103 compared to 503) and kidneys. Clinical sign scores of the challenged groups showed significant effect of the vaccination program to reduce clinical signs. The trachea pathological scores and histopathological findings in the lungs and kidneys also confirmed better protective efficacy of vaccinated groups. In conclusion, using combination of heterologous IBV vaccine serotypes (Massachusetts and 793/B) would be a better strategy to control variant 2-like viruses, but more evaluation is needed using other circulating isolates to find the best combination of vaccines.

Pathogenicity characteristics of an Iranian variant-2 (IS-1494) like infectious bronchitis virus in experimentally infected SPF chickens

Avian infectious bronchitis (IB) is a major cause of economic loss to the poultry industry. IB virus primarily affects respiratory tract, but strains differ in their tropism for such other target organs as kidneys and alimentary tract. The objective of this study was to estimate the pathogenicity of an Iranian IB virus (IBV) variant (variant-2) which is one of the most prevalent isolates circulating in Iranian poultry farms. SPF chickens were intranasally inoculated with 104 EID50/0.1 ml of the virus. Sera, fecal swabs, and different tissue samples were collected on different days post infection. Clinical signs, gross pathology, and histological changes were recorded. The amount of virus genome was quantified in different tissues and feces using quantitative real-time PCR assay. The highest viral loads were detected in the feces and cecal tonsils. Real-time PCR results demonstrated variant-2 tropism for respiratory tract, digestive system and renal tissue that is due to its epitheliotropic nature. This is the first pathogenicity study of Iranian variant-2 virus. Based on histology observations and clinical signs this isolate was classified as a nephropathogenic IBV. Further knowledge of IBV pathogenesis permits to perform more effective prevention practice.

Uterine leiomyoma and its association with menstrual pattern and history of depo-medroxyprogesterone acetate injections

BACKGROUND AND AIM

Despite the high prevalence of uterine leiomyoma, according to recent review studies there is uncertainty and a paucity of information regarding its predisposing or protective factors. The aim of this study was to assess the possible association between menstrual cycle pattern and occurrence of surgically treated myomas and also to check if depo-medroxyprogesterone acetate (DMPA) injection earlier in reproductive life can affect the later occurrence of myomas needing surgical treatment.

METHODS

In a case-control study in Ardabil, 85 women with definite diagnosis of surgically treated uterine leiomyoma and 154 community controls were enrolled. Possible predictors of myoma including menstrual cycle and menstrual bleeding patterns were assessed. Data were analyzed using SPSS software (SPSS, IBM, Somers, NY). Odds ratios were used as the main statistic in assessing the strength of observed associations.

RESULTS

Mean age of the participants was 41.8 ± 8.5 years. Length of menstrual cycle was associated with myoma and a higher likelihood of myoma was observed among those having shorter menstrual cycles (P < 0.05). Number of menstrual bleeding days was also associated with surgically treated myoma and longer bleeding periods increased the likelihood of myoma (P < 0.05). Only one of the eight women who had a history of depo-medroxyprogesterone acetate injections had developed surgically treated uterine leiomyoma and the others belonged to the control group without a history of surgical treatment for uterine leiomyoma.

CONCLUSION

Menstrual cycle pattern is associated with developing leiomyomas requiring surgical treatment. DMPA, other than its role in myoma treatment, is also assumed to have a role in preventing myomas, but due to the small sample size in this study, larger scale prospective trials are needed in the future.

Simultaneous spectrophotometric determination of paracetamol, phenylephrine and chlropheniramine in pharmaceuticals using chemometric approaches

BACKGROUND AND THE PURPOSE OF THE STUDY

The linear multivariate calibration models such as principal components regression (PCR) and partial least squares regressions (PLS1 and PLS2) due to the mathematical simplicity and physical or chemical interpretability are sufficient and generally preferred method for analysis of multicomponent drugs. In this study, simultaneous determination of paracetamol, phenylephrine and chlorpheniramine in pharmaceuticals using chemometric methods and UV spectrophotometry is reported as a simple alternative technique.

MATERIAL AND METHODS

Principal components regression (PCR) and partial least squares regressions (PLS1 and PLS2) were used for chemometric analyses of data obtained from the spectra of paracetamol, phenylephrine and chlorpheniramine between wavelengths of 200 to 400 nm at several concentrations within their linear ranges. The analytical performance of these chemometric methods were characterized by relative prediction errors and recoveries (%) and compared with each other.

RESULTS

PCR, PLS1 and PLS2 were successfully applied to a tablet formulation, with no interference from excipients as indicated by the recovery. However, the PLS1 shows better results due to its flexibility and mathematical principals.

CONCLUSION

The proposed methods are simple and rapid requiring no separation step, and can be easily used as an alternative in the quality control of drugs.

Soft-modeling based spectrofluorimetric study of simultaneous equilibria

A two-way soft resolution method will fail when applied to a simultaneous equilibria system due to rank deficiency in its concentration profiles. Increasing the dimensionality of measurements from two-way to three-way data can be used to overcome this problem. Simultaneous dissociation of two weak acids is considered as a model for simultaneous equilibria. Three-way data obtained from excitation-emission spectrofluorimetric monitoring of a pH-metric titration is analyzed using a proper combination of well-known soft-modeling methods. Multivariate curve resolution-alternating least squares is used for calculating the excitation and emission spectral profiles of involved species and rank annihilation factor analysis for obtaining the contribution of each species in measured excitation-emission matrices at different pHs. The results of simulated and real simultaneous acids dissociation equilibria showed that the proposed combined method performs well even in situation when the equilibrium constants are close to each other. The applicability of method for study of an acidic dissociation is also shown.

Simultaneous spectrophotometric determination of paracetamol, ibuprofen and caffeine in pharmaceuticals by chemometric methods

In this study, the simultaneous determination of paracetamol, ibuprofen and caffeine in pharmaceuticals by chemometric approaches using UV spectrophotometry has been reported as a simple alternative to using separate models for each component. Spectra of paracetamol, ibuprofen and caffeine were recorded at several concentrations within their linear ranges and were used to compute the calibration mixture between wavelengths 200 and 400 nm at an interval of 1 nm in methanol:0.1 HCl (3:1). Partial least squares regression (PLS), genetic algorithm coupled with PLS (GA-PLS), and principal component-artificial neural network (PC-ANN) were used for chemometric analysis of data and the parameters of the chemometric procedures were optimized. The analytical performances of these chemometric methods were characterized by relative prediction errors and recoveries (%) and were compared with each other. The GA-PLS shows superiority over other applied multivariate methods due to the wavelength selection in PLS calibration using a genetic algorithm without loss of prediction capacity. Although the components show an important degree of spectral overlap, they have been determined simultaneously and rapidly requiring no separation step. These three methods were successfully applied to pharmaceutical formulation, capsule, with no interference from excipients as indicated by the recovery study results. The proposed methods are simple and rapid and can be easily used in the quality control of drugs as alternative analysis tools.

Performance comparison of neural network training algorithms in modeling of bimodal drug delivery

The major aim of this study was to model the effect of two causal factors, i.e. coating weight gain and amount of pectin-chitosan in the coating solution on the in vitro release profile of theophylline for bimodal drug delivery. Artificial neural network (ANN) as a multilayer perceptron feedforward network was incorporated for developing a predictive model of the formulations. Five different training algorithms belonging to three classes: gradient descent, quasi-Newton (Levenberg-Marquardt, LM) and genetic algorithm (GA) were used to train ANN containing a single hidden layer of four nodes. The next objective of the current study was to compare the performance of aforementioned algorithms with regard to predicting ability. The ANNs were trained with those algorithms using the available experimental data as the training set. The divergence of the RMSE between the output and target values of test set was monitored and used as a criterion to stop training. Two versions of gradient descent backpropagation algorithms, i.e. incremental backpropagation (IBP) and batch backpropagation (BBP) outperformed the others. No significant differences were found between the predictive abilities of IBP and BBP, although, the convergence speed of BBP is three- to four-fold higher than IBP. Although, both gradient descent backpropagation and LM methodologies gave comparable results for the data modeling, training of ANNs with genetic algorithm was erratic. The precision of predictive ability was measured for each training algorithm and their performances were in the order of: IBP, BBP>LM>QP (quick propagation)>GA. According to BBP-ANN implementation, an increase in coating levels and a decrease in the amount of pectin-chitosan generally retarded the drug release. Moreover, the latter causal factor namely the amount of pectin-chitosan played slightly more dominant role in determination of the dissolution profiles.

Simultaneous spectrophotometric determination of Fe(III), Al(III) and Cu(II) by partial least-squares calibration method

A spectrophotometric method for simultaneous determination of Fe(III), Al(III) and Cu(II) using Alizarin Red S as a chelating agent was developed. The parameters controlling behavior of the system were investigated and optimum conditions were selected. A partial least-squares multivariate calibration method was used for the analysis of ternary mixtures of Fe(III), Al(III) and Cu(II) over the range of 450-6000, 140-4000 and 450-15000 ng ml(-1), respectively. Absorbance data were taken between 400 and 800 nm. Applying this method to simultaneous determination of these metal ions in several synthetic alloy solutions with total relative standard error of less than 5% validated the proposed method.

Creatinine, blood urea nitrogen and thyroid hormone levels before and after haemodialysis

A study was carried out on 57 patients with chronic renal failure in a hospital in Kerman city, Islamic Republic of Iran. Blood samples were taken before and after haemodialysis to measure blood urea nitrogen and serum creatinine, triiodothyronine (T3) and thyroxine (T4) levels. Findings revealed that before dialysis T4 in 11 cases and T3 in 29 cases were lower than the normal range, but after haemodialysis only 3 cases for T4 and 15 cases for T3 were lower than normal levels. The remaining cases reverted to normal state. We suggest that a feedback relationship exists between the major end catabolic products (creatinine and blood urea nitrogen) and thyroid hormone serum levels.

Cloud point extraction, preconcentration and simultaneous spectrophotometric determination of nickel and cobalt in water samples

Cloud point extraction has been used for the preconcentration and simultaneous spectrophotometric determination of nickel and cobalt after the formation of a complex with 2-amino-cyclopentene-1-dithiocarboxylic acid (ACDA), and latter analysis by spectrophotometer using Triton X-114 as surfactant. The parameters affecting the separation phase and detection process were optimized. Under the optimum experimental conditions (i.e. pH=5, 0.07 mM ACDA, Triton X-114=0.25% (w/v)), calibration graphs were linear in the range of 20-500 and 20-200 microg l(-1) with detection limits of 10 and 7.5 microg l(-1) for Ni and Co, respectively. The method was applied to the determination of Ni and Co in natural and waste water samples with satisfactory results.

Differentiation of bovine and porcine gelatins using principal component analysis

Gelatin is a collagen derivative, which has a large application in the pharmaceutical, food and adhesive industries as well as photography. The large similarity in structure and properties of gelatins from different origins makes their differentiation difficult. Certain chemometric methods, such as principal component analysis (PCA), can help to classify and characterize gelatin components. In this study 14 bovine and 5 porcine gelatins were examined. The analysis procedure involved complete hydrolysis of samples by classic acid hydrolysis in order to release their amino acid residues. Separation and determination of amino acids was achieved by reversed-phase (RP) HPLC following pre-column derivatisation. Orthophtaldialdehyde (OPA) and 4-chloro-7-nitro benzofurazane (NBD-Cl) were used as derivatisation reagents. From the 20 peaks detected by HPLC analysis, one was very typical in bovine gelatin. Peak height, area, area percentage and width were used to make matrixes. Principal component analysis with the MATLAB program was used to differentiate these gelatins. PCA on matrix of height, width and total matrix were resulted in good differentiation between bovine and porcine gelatins.

A member of the delta subgroup of proteobacteria from a pyogenic liver abscess is a typical sulfate reducer of the genus Desulfovibrio

Strain FH26001/95 (ATCC 700045) was previously isolated from a pyogenic liver abscess from a human. Comparative 16S rRNA gene sequence analysis showed that this strain is related to members of the delta subgroup of the proteobacteria, within a cluster of sulfate-reducing bacteria (Desulfovibrio spp.) and non-sulfate-reducing bacteria (Bilophila wadsworthia and Lawsonia spp.). The phenotype of strain FH26001/95 was found to be typical of members of the genus Desulfovibrio. Growth and substrate transformations were possible at oxygen concentrations of 2 to 5% (vol/vol) but not at oxygen concentrations of 21% (vol/vol) in air. Its isolation from an infection in a human suggests that some members of the genus Desulfovibrio can be considered opportunistic pathogens.

Growth of mixed cultures ofParacoccus denitrificans andDesulfovibrio desulfuricans in homogeneous and in heterogeneous culture systems

Obligate aerobes and anaerobes coexist closely in natural ecosystems. One species representative of each class (Desulfovibrio desulfuricans andParacoccus denitrificans) were selected for investigation in different laboratory growth systems. When incubated together, the aerobe protected the anaerobe against oxygen poisoning allowing the latter to grow and to reduce sulfate. When gas phase oxygen tension was systematically altered in stirred batch cultures, both species grew over a broad range of oxygen concentrations. Similar experiments in a chemostat indicated that conditions were far more exacting. No steady state was possible; however, at one critical oxygen tension the two species entered a stable oscillating cycle that lasted for 12 days. When the two organisms were grown in a gradostat in opposing gradients of sulfate plus oxygen and lactate, they coexisted but at different positions in the system. The actual position of the sulfate reducer was determined by the sulfate concentration in the reservoir.

Serological characteristics within the genus Desulfovibrio

Antisera were prepared against one strain each of Desulfovibrio desulfuricans, D. vulgaris and D. salexigens. The antisera were tested for cross reactivity against 36 heterologous Desulfovibrio strains by both agglutination titration and by double immunodiffusion percipitin plates. Generally no cross-reaction was demonstrated by agglutination even between heterologous strains of the same species, suggesting that the surface antigens of Desulfovibrio are highly specific. In immunodiffusion plates a single apparently genus-specific surface antigen could be shown to be present in all but two of the strains tested. Although other common precipitin bands showed the presence of some antigens common between heterologous strains these appeared to be randomly distributed among the strains tested, with the exception of one band shown to be generally specific to strains of D. salexigens. With this exception no other precipitin band could be shown to be consistently specific to any other species, nor consistently common to more than one species.

Seasonal temperature as a factor influencing bacterial sulfate reduction in a saltmarsh sediment

The population of sulfate-reducing bacteria in saltmarsh sediment was examined at monthly intervals by plate-counting and by determining the response of sulfate reduction rates to environmental temperature using(35)SO 4 (2-) . The sulfate reduction rate was shown to be related to temperature by an Arrhenius function.The temperature characteristic of the population of sulfate-reducing bacteria did not vary significantly with season, and was shown to be equivalent to 20.4 kcals mole(-1), a Q10 of 3.5. Apart from one anomolous result, the monthly value for the Arrhenius constant also did not show any significant variation throughout the year. There was no seasonal trend of optimum temperature for sulfate reduction.The results suggested that, although environmental temperature was the dominant variable influencing sulfate reduction rates in the sediment, there was no detectable response or adaptation of the sulfate-reducing population to seasonally changing environmental temperature.