A DNA functionalized advanced electrochemical biosensor for identification of the foodborne pathogen Salmonella enterica serovar Typhi in real samples.

An efficient platform for the detection of Salmonella enterica serovar Typhi (S. Typhi) is essential for early-stage diagnosis of typhoid to prevent and contain outbreaks. Here, we fabricated an electrochemical DNA biosensor for selective identification of S. Typhi in real samples. The biosensor has been fabricated by immobilizing an amine labelled S. Typhi specific single-strand capture probe on the surface of gold nanoparticles (AuNP) and poly cysteine (P-Cys) modified screen-printed electrode. Differential pulse voltammetry (DPV) of anthraquinone-2-sulfonic acid monohydrate sodium salt (AQMS) as a signal indicator was monitored to detect S. Typhi by hybridization of target DNA with the probe DNA. The fabricated biosensor shows a detection range of 1 × 10-6 to 1 × 10-22 molL-1 with a LOD of 6.8 × 10-25 molL-1 in S. Typhi complementary linear target and 1.8 × 105 to 1.8 CFUml-1 with a LOD of 1 CFUml-1 in a real S. Typhi sample. The biosensor shows excellent discrimination ability to some bases mismatched and different bacterial cultures (same and distant genera). The most beneficial points of the proposed DNA biosensor are the lower limit of detection and the ability to reuse the biosensor more than 6 to 7 times. In addition, the practicability of the biosensor was investigated via detecting S. Typhi in blood, poultry feces, egg, and milk whereby excellent recoveries ranging from 96.54 to 103.47% were demonstrated indicating that this biosensor might be the most promising diagnostic tool for monitoring S. Typhi in clinical and food samples.

Ceftizoxime loaded ZnO/L-cysteine based an advanced nanocarrier drug for growth inhibition of Salmonella typhimurium.

L-Cysteine coated zinc oxide (ZnO) nano hollow spheres were prepared as a potent drug delivery agent to eradicate Salmonella enterica serovar Typhimurium (S. typhimurium). The ZnO nano hollow spheres were synthesized by following the environmentally-friendly trisodium citrate assisted method and L-cysteine (L-Cys) conjugate with its surface. ZnO/L-Cys@CFX nanocarrier drug has been fabricated by incorporating ceftizoxime with L-Cys coated ZnO nano hollow spheres and characterized using different techniques such as scanning electron microscope (SEM), attenuated total reflection Fourier transform infrared (ATR-FTIR), and X-ray diffraction (XRD) etc. Furthermore, the drug-loading and encapsulation efficiency at different pH levels was measured using UV-vis spectrometer and optimized. A control and gradual manner of pH-sensitive release profile was found after investigating the release profile of CFX from the carrier drug. The antibacterial activity of ZnO/L-Cys@CFX and CFX were evaluated through the agar disc diffusion method and the broth dilution method, which indicate the antibacterial properties of antibiotics enhance after conjugating. Surprisingly, the ZnO/L-Cys@CFX exhibits a minimum inhibitory concentration (MIC) of 5 µg/ml against S. typhimurium is lower than CFX (20 µg/ml) itself. These results indicate the nanocarrier can reduce the amount of CFX dosed to eradicate S. typhimurium.

A highly sensitive poly-arginine based MIP as an electrochemical sensor for selective detection of dimetridazole.

In this experiment, a highly effective electrochemical sensor based on a molecularly imprinted polymer has been developed for ultrasensitive detection of dimetridazole. The sensor was made by incorporating of dimetridazole as a template molecule during the electropolymerization of poly-arginine on a glassy carbon electrode. The modified electrode GCE/P-Arg@MIP was characterized by voltammetric and microscopic techniques. Differential pulse voltammetry method was used to detect target analyte under the optimum condition. The DPV response to dimetridazole was linear at 0.1 × 10-9 to 10 × 10-6 mol L-1 (R2 = 0.996), with a method detection limit (S/N = 3) of 0.1 × 10-9 mol L-1. Moreover, the proposed sensor shows satisfactory recovery ranges for the determination dimetridazole in commercially available egg, milk and honey samples.

Ultra-sensitive electrochemical detection of oxidative stress biomarker 8-hydroxy-2'-deoxyguanosine with poly (L-arginine)/graphene wrapped Au nanoparticles modified electrode.

An innovative electrochemical sensor assembly relying on a simple "green" electrochemical reduction route is presented for the sensitive detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG), the most abundant oxidative product of DNA. The sensing film consisted of poly (L-arginine) and graphene wrapped Au nanoparticles was fabricated on glassy carbon electrode (GCE/P-Arg/ErGO-AuNPs) using subsequent 'layer-by-layer' regime through electrochemical technique. The proposed method was also successfully applied for the quantification of 8-OHdG in the presence of interfering biomolecules like ascorbic acid and uric acid. Scanning electron microscopy (SEM) was utilized to characterize the surface morphology of the composite electrode. Electrochemical characterizations of the bare and modified electrodes were carried out via cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). According to differential pulse voltammetry (DPV) results, there were linear relationships between the peak currents and the concentrations in the ranges of 1.0-100 nM (R2 = 0.996), and 0.5-10 µM (R2 = 0.990), with a detection limit (S/N = 3) of 1.0 nM. Furthermore, the proposed sensor was successfully applied for the determination of target analyte in human urine samples and a very high recovery percentage was obtained.

Pyrolytic Waste Plastic Oil and Its Diesel Blend: Fuel Characterization.

The authors introduced waste plastic pyrolysis oil (WPPO) as an alternative fuel characterized in detail and compared with conventional diesel. High density polyethylene, HDPE, was pyrolyzed in a self-designed stainless steel laboratory reactor to produce useful fuel products. HDPE waste was completely pyrolyzed at 330-490°C for 2-3 hours to obtain solid residue, liquid fuel oil, and flammable gaseous hydrocarbon products. Comparison of the fuel properties to the petrodiesel fuel standards ASTM D 975 and EN 590 revealed that the synthetic product was within all specifications. Notably, the fuel properties included a kinematic viscosity (40°C) of 1.98 cSt, density of 0.75 gm/cc, sulphur content of 0.25 (wt%), and carbon residue of 0.5 (wt%), and high calorific value represented significant enhancements over those of conventional petroleum diesel fuel.

Assessing estrogenic chemicals in anchovy and mussel samples from Karachi, Pakistan with the yeast estrogen screen bioassay.

Endocrine disrupting chemicals (EDCs) are introduced into the aquatic environment through industrial and municipal effluents along with urban and agricultural runoffs. Exposure of aquatic organisms to EDCs may lead to hormonal disruption and adverse health effects. The goals of our study were: to collect anchovy and mussel samples from the coastal region of Karachi, to use the yeast estrogen screen (YES) bioassay in estimating xeno-estrogen content in these samples, and to investigate if the bioassay could be used to quantify known amounts of 17ß-estradiol (E2) injected into cod and salmon fillets. Results of the studies showed that mussel estrogenic activity in Karachi decreased in the order of Buleji point 1 (8.91 ± 4.77, mean ± SD) > Paradise point 1 (1.72 ± 0.81) > Paradise point 2 (0.61 ± 0.84) ng E2 equivalents/g wet wt (p < 0.05). By comparison, anchovy estrogenic activity at Korangi/Phitti Creek was much higher than at Manora. Together, these results confirmed previous reports that both Buleji point 1 and Korangi/Phitti Creek were the most contaminated areas of Karachi. The YES bioassay was only a semi-quantitative method in determining the contents of xeno-estrogens in aquatic organisms; it consistently overestimated the amounts of E2 injected into cod and salmon fillets due to additive and/or non-additive interactions between E2 and endogenous estrogens. Nevertheless, the YES bioassay was able to identify the contaminated sites in the coastal region of Karachi.

Pulsed radiofrequency modulation for lingual neuralgia.

Pulsed radiofrequency modulation (PRM) is a minimally invasive procedure that has been used successfully to treat neuropathic pain. Its use to treat lingual neuralgia has not to our knowledge been described previously, and we report a case.

The chemokine CXCL12 promotes survival of postmitotic neurons by regulating Rb protein.

Postmitotic neurons need to keep their cell cycle under control to survive and maintain a differentiated state. This study aims to test the hypothesis that the chemokine CXCL12 regulates neuronal survival and differentiation by promoting Rb function, as suggested by previous studies showing that CXCL12 protects neurons from apoptosis induced by Rb loss. To this end, the effect of CXCL12 on Rb expression and transcriptional activity and the role of Rb in CXCL12-induced neuronal survival were studied. CXCL12 increases Rb protein and RNA levels in rat cortical neurons. The chemokine also stimulates an exogenous Rb promoter expressed in these neurons and counteracts the inhibition of the Rb promoter induced by E2F1 overexpression. Furthermore CXCL12 stimulates Rb activity as a transcription repressor. The effects of CXCL12 are mediated by its specific receptor CXCR4, and do not require the presence of glia. Finally, shRNA studies show that Rb expression is crucial to the neuroprotective activity of CXCL12 as indicated by NMDA-neurotoxicity assays. These findings suggest that proper CXCR4 stimulation in the mature CNS can prevent impairment of the Rb-E2F pathway and support neuronal survival. This is important to maintain CNS integrity in physiological conditions and prevent neuronal injury and loss typical of many neurodegenerative and neuroinflammatory conditions.

Pathological effects of formalin (37% formaldehyde) feeding in female Japanese quails (Coturnix coturnix japonica).

The aim of this study was to determine the pathological effects of formalin on female quails. Seventy-five 1-day-old female Japanese quails (Coturnix coturnix japonina) were divided into five equal groups (A-E) and fed formalin daily at dose levels of 20, 10, 5, 2.5 and 0 mL/ kg feed, respectively. All birds were slaughtered at the end of the experiment -- the eighth week. No clinical signs were observed in quails fed 2.5 mL formalin/kg feed. Depression, dullness and anorexia were prominent in quails fed 20 mL formalin/kg feed. Feed intake, body weight, egg production and egg weight together with absolute and relative weight of organs, erythrocyte and leukocyte counts, hemoglobin concentration and hematocrit were decreased at higher doses, i.e., 10 and 20 mL formalin/kg feed. Total serum proteins and globulin significantly increased (P <0.05) in all formalin fed quails compared to control birds. No gross lesions were observed in the 2.5 mL formalin/kg fed group. At higher doses (10 and 20 mL formalin/kg feed) hemorrhages on the thigh muscles, decreased weight and reduction in area and folds of different segments of oviduct were recorded. Reduced size of liver, heart and kidneys was recorded in quails fed 20mL formalin/kg feed compared to controls and other birds. The histopathological changes in oviduct consisted of degeneration of mucosal glands characterized by vacuolation of nuclei of cells. It was concluded from the study that formalin feeding to female quails at 2.5 mL/kg feed is without harmful effects, however, higher doses are not without health risks.

Pathological effects of formalin (37% formaldehyde) mixed in feed or administered into the crops of White Leghorn cockerels.

This study compared the adverse effects of formalin administered by two different methods. Formalin mixed with the feed (2.5, 5.0 and 10 ml/kg) was given to 10-week-old White Leghorn cockerels for a period of 8 weeks. Simultaneously in other groups, a 3% solution of formalin was administered into the crops (5, 10, 15 and 20 ml/bird/day). Total amount of formalin utilized during the experiment in the feed of individual bird of groups given 2.5, 5 and 10 ml/kg was 6.25, 3.9 and 1.6% higher than those administered 5, 10 and 20 ml of 3% formalin into crop, respectively. Body mass and feed intake in all feed-mixed groups and those given 5 and 10 ml formalin (3%) into the crop were not significantly different from control. Administration of 15 and 20 ml formalin (3%) into crop resulted in depression, delayed onset of crowing, significantly decreased feed intake, lower body mass, decreased mass and volume of testes, ulceration in crops, sloughing of mucosa and petechial haemorrhages in proventriculus. All the groups given formalin had significantly smaller diameters of seminiferous tubules. Kidneys of the birds administered formalin into crop exhibited pyknotic nuclei of epithelial cells in proximal tubules. Non-significant differences in different parameters and lesser degree of pathological changes in birds given formalin-mixed feed than their corresponding crop-administered groups suggested that formalin present in the feed had partially evaporated. Therefore, birds ingested less amount of formalin than that originally mixed in the feed.

Cytopathological grading, as a predictor of histopathological grade, in ductal carcinoma (NOS) of breast, on air-dried Diff-Quik smears.

Fine-needle aspiration cytology (FNAC) is a widely practiced technique in the diagnosis of breast carcinoma, and it is the only diagnostic procedure performed before definitive treatment, at most institutions. While the histological grading of breast carcinoma has become routine in many centers worldwide, the cytopathological grading of breast carcinoma is not commonly used. Grading of breast carcinoma, while the tumor is still in vivo, would be the most ideal and desirable situation, as it would be helpful in the selection of patients for appropriate therapy. The objective of this study, therefore, was to devise a simple system for grading breast carcinoma, based on the cytological features alone. We reviewed 125 cases of breast carcinoma retrospectively, which were initially diagnosed by FNAC, with subsequent histopathological confirmation. These included 105 ductal, 6 lobular, 2 tubular, 1 papillary, and 1 medullary carcinoma. There was 1 ductal carcinoma in situ. Nine cases were rendered insufficient for grading. Thus 105 cases of ductal carcinoma (NOS) were evaluated for final cytological grading. Air-dried Diff-Quik-stained smears were reviewed at least twice independently by four histopathologists and were then compared with the original histological grades. Six cytological features used for grading were found to be statistically significant: cellular pleomorphism, nuclear size, nuclear margin, nucleoli, naked tumor nuclei, and mitoses. A scoring system based on these six essential parameters was used, to classify ductal carcinoma into three cytological grades, which showed close correlation with the established histological grades. In addition, two less consistent, but still important, features were the presence or absence of necrosis and stromal invasion. Another six parameters, including smear cellularity, degree of cell dispersion or clustering, lymphoplasmacytic infiltrate, presence of tubular structures, cytoplasmic appearance of the tumor cells, and smear background, were not statistically significant. However, these additional parameters were found helpful in assigning the correct grade, in cases with borderline scores. The concordance rate with histology was 100% for grade 1, 98% for grade 2, and 93% for grade 3.

Concentrations of four fecal steroids in wild baboons: short-term storage conditions and consequences for data interpretation.

One source of both bias and "noise" in fecal steroid analysis is temporal change in steroid concentrations resulting from duration or conditions of fecal sample storage. However, no consensus currently exists regarding correct procedures or precautions necessary for fecal sample storage, and conditions vary widely within field endocrinology literature. This study considered the effects of short-term, weeks-long, storage conditions on quantifiable fecal testosterone (fT), glucocorticoids (fGC), estrogens (fE), and progestagen (fP) metabolite concentrations in wild baboons (Papio cynocephalus). Quadruplicate subsamples of fecal samples (n=29) collected at Amboseli National Park and its environs were subjected to four different storage conditions prior to lyophilization, in order to determine the effects of storage on subsequent steroid concentrations, as assessed by 125I radioimmunoassays. As expected, the best alternative to the "initial condition" of lyophilization at three days after collection was to freeze fecal samples at -20 degrees C for two weeks prior to lyophilization. This storage method resulted in no significant change from initial steroid concentrations for fE, fT, or fP, although fGC showed a slight but significant decline. Storage for two weeks in a charcoal refrigerator caused a mean increase in all four steroid concentrations. However, the results from this storage condition were robust in terms of practical questions asked of the data: fE and fP values still reflected pregnant versus non-pregnant states in baboon females; a fGC profile constructed by age class resembled that created from the samples from the initial condition, although slightly inflated across age classes; and there were only moderate changes in relative fT concentrations across adult males. Knowledge of the effects of storage upon each steroid analyzed within one's study is a necessary component in determining the optimal compromise for storage protocol in a particular research project.

A matter of time: evaluating the storage of fecal samples for steroid analysis.

The extraction and immunoassay of fecal steroids is an increasingly common technique, used in both captive and field studies to provide an approximation of an animal's circulating concentration of hormones through non-invasive methods. Storage of fecal samples is of critical concern because fecal bacteria metabolize fecal steroids within hours after deposit. Ethanol is often used as a preservative for fecal samples stored for several hours at room temperature. We examined the stability of fecal estrogen (fE) and glucocorticoid (fGC) metabolites from baboon (Papio cynocephalus) samples in a 95% ethanol solution at ambient temperature and at -20 degrees C over the course of six months, to determine the effect of storage on steroid concentrations. As measured by radioimmunoassay, fE metabolite concentrations increased by 122% at 90 days and fGC metabolite concentrations increased by 92% at 120 days. After peaking, both hormones declined to near initial concentrations by 180 days in ambient temperature samples. In samples stored at sub-zero temperatures, fGC metabolite concentrations showed a similar but dampened pattern, while fE metabolite concentrations exhibited small and variable changes with no consistent trend. We discuss explanations for the dynamic pattern of changing fecal metabolite concentrations and offer practical and analytical guidance to field workers for situations in which ideal conditions for stabilizing hormones are not available.

Large granular lymphocytes in the oviduct of developing and hormone-treated chickens.

1. In the present study the distribution of large granular lymphocytes (LGLs) and influence of oestrogen on these cells was investigated in the oviduct of chickens by the observation of H and E stained sections. 2. The LGLs first appeared in the oviduct at 9 weeks and their frequency of occurrence increased with age and was highest in the infundibulum and vagina from 21 to 32 weeks of age. The frequency of occurrence of LGLs from magnum to uterus (glandular part) was low. These cells were located at the base, middle and apical parts of the lining epithelium as well as in the sperm-storage glandular epithelium. 3. When chickens of 21 weeks were treated with DES, LGLs abundantly infiltrated in the oviducal epithelium in comparison to the control. 4. These results suggested that the development of LGLs in the oviduct of chickens correlates with oestrogen secretion.

Relation of preoperative sialographic findings with histopathological diagnosis in cases of obstructive sialadenitis of the parotid and submandibular glands: retrospective study.

The clinical records, preoperative sialograms and histopathological slides of 33 patients who had been operated on for symptoms of obstructive salivary gland disease were reviewed. Twenty patients had had superficial parotidectomy and 13 excision of the submandibular gland. Among those who had required parotidectomy, preoperative sialograms tended to suggest more architectural damage than was actually noted on definitive histopathological examination. Patients whose symptoms had been present for longer had more severe sialographic and histopathological changes. In the submandibular group, there was a closer relation between sialographic and histopathological changes, and a positive correlation between a short history and the severity of histopathological grading. These differences may reflect the different aetiology and course of obstructive disease in the two types of gland.

Macrophages in the chicken oviduct: morphometrical studies by light and transmission electron microscopy and the possible influence of sex hormones.

Light and electron microscopic techniques were used to study the morphometry and dynamic changes of macrophages in the postnatal and sex hormone-treated chicken oviduct, respectively. Abundant typical macrophages, containing clear vacuoles, well-developed mitochondria, Golgi complexes and lysosomal bodies in their cytoplasms, were observed in the lamina propria of all segments of the postnatal chicken oviduct, occurring more frequently in the vaginal part. When 7-day-old chickens were injected with diethylstilbestrol (DES), and DES plus progesterone, infiltration of a significant number of macrophages in both groups, but not in controls could be seen. The light and electron microscopic structures of the macrophages in both postnatal and sex hormone-treated chicken oviduct were similar. These results show that typical macrophages are present in the chicken oviduct; their frequency of occurrence varies with different oviductal segments, and they are influenced by sex hormones.

Postnatal development of B lymphocytes and immunoglobulin-containing plasma cells in the chicken oviduct: studies on cellular distribution and influence of sex hormones.

Postnatal development of B lymphocytes and plasma cells containing different classes of immunoglobulins (IgG, IgA, and IgM) was immunohistochemically studied in the oviduct of the Dekalb strain of the White Leghorn chicken. B lymphocytes first appeared in the lamina propria of the chicken oviduct at 5 weeks of age. Their frequency of occurrence peaked at 15 weeks from the infundibulum to the uterus (glandular part), while in the vagina (aglandular part) it did so at 21 weeks. Intraepithelial B lymphocytes were very rare and exclusively located in the vagina at 19 and 21 weeks. Plasma cells first appeared in the lamina propria of the oviduct at 11 weeks of age, and this frequency peaked at 32 weeks. IgG-containing plasma cells were most numerous in the glandular part, whereas in the aglandular part IgA and IgM cells were more numerous than IgG cells. When 7-day-old-chickens were treated with sex hormones, B lymphocytes and plasma cells appeared 12 h and 5 days after the hormone injection, respectively. Their frequency of occurrence was statistically higher in diethylstibestrol (DES)-treated chickens than in DES plus progesterone-treated chickens. This suggests that the postnatal development of B lymphocytes and plasma cells in the oviduct of the chicken is correlated to estrogen secretion.

Hormonal regulation of T-cell subsets in the oviduct: an immunohistochemical study using sex-hormone-treated chicken.

The present immunohistochemical study deals with dynamic alteration of T-cell subsets in the oviduct sex-hormone-treated chickens. Monoclonal antibodies (CT3, CT4, and CT8) specific for the chicken homologues of CD3, CD4, and CD8 were used in estrogen- or progesterone-treated chickens. In control animals, no lymphocytes appeared throughout the oviduct until 4 weeks of age. When 7-day-old chickens were injected with either diethylstilbestrol (DES) or (DES) plus progesterone, T cells immunoreactive for CT3 first infiltrated the oviduct at 12 hr after the hormone treatment. Their frequency of occurrence rose from 48 to 96 hr. Subsequently, CT3+ cells in the magnum declined in number per area coincident with the proliferation of albuminous glands in the lamina propria, while in the vagina no decline of T cells was observed. The population of T-cell subsets in the lamina propria of both the magnum and vagina was significantly higher in the DES-treated chickens than in DES plus progesterone-treated chickens. Among T-cell subsets CT8+ cells were more numerous than CT4+ cells throughout the study, this relative frequency being shared by normal adults. Depopulation of lymphocytes from the thymus, spleen and cecal tonsil, their mobilization to the circulating blood, and subsequent dynamic infiltration into the oviduct suggested that the sex hormones induced the traffic of T cells from the lymphoid organs into the oviduct.

Tumorigenicity, invasion and metastasis of the small cell lung cancer cell line NCI-H69 and two derivative lines MOG-H69V and MOG-H69VZ.

Two adherent cell lines MOG-H69V and MOG-H69VZ have been isolated from a continuous cell line, NCI-H69, derived from human small cell lung cancer by Carney et al, [1987]. They have been established and characterised morphologically, biochemically, and for growth characteristics in vitro Khan et al (19). In the present study both the parental and the derivative lines have been investigated for invasiveness in vitro and in vivo. The parental line showed an early invasiveness compared with both the derivative cell lines. All cell lines formed tumours in nude mice with 100% take rate. Xenograft histology of all the cell lines revealed pleomorphic tumours, however the derivative lines showed areas of focal, large, spindle cells containing both acidic and neutral mucin, and spaces between the cells were found filled with alcianophilic, amorphous material. The parental line was invasive and metastatic. Tumours of both the derivative lines were non-metastatic under similar conditions. They were also investigated for neuroendocrine-cell marker expression. These data show that while the behaviour of the parental line was compatible with small cell lung cancer, that of the derivative lines was more indicative of non-small cell lung cancer, both in vitro and in vivo. As previous data suggested a common origin of the parental and the derivative lines, probably from a stem cell subpopulation present in the parental line, these lines represent a useful model for the study of phenotypic changes in lung cancer.