Deformed graphene FET biosensor on textured glass coupled with dielectrophoretic trapping for ultrasensitive detection of GFAP

Numerous efforts have been undertaken to mitigate the Debye screening effect of FET biosensors for achieving higher sensitivity. There are few reports that show sub-femtomolar detection of biomolecules by FET mechanisms but they either suffer from significant background noise or lack robust control. In this aspect, deformed/crumpled graphene has been recently deployed by other researchers for various biomolecule detection like DNA, COVID-19 spike proteins and immunity markers like IL-6 at sub-femtomolar levels. However, the chemical vapor deposition (CVD) approach for graphene fabrication suffers from various surface contamination while the transfer process induces structural defects. In this paper, an alternative fabrication methodology has been proposed where glass substrate has been initially texturized by wet chemical etching through the sacrificial layer of synthesized silver nanoparticles, obtained by annealing of thin silver films leading to solid state dewetting. Graphene has been subsequently deposited by thermal reduction technique from graphene oxide solution. The resulting deformed graphene structure exhibits higher sensor response towards glial fibrillary acidic protein (GFAP) detection with respect to flat graphene owing to the combined effect of reduced Debye screening and higher surface area for receptor immobilization. Additionally, another interesting aspect of the reported work lies in the biomolecule capture by dielectrophoretic (DEP) transport on the crests of the convex surfaces of graphene in a coplanar gated topology structure which has resulted in 10 aM and 28 aM detection limits of GFAP in buffer and undiluted plasma respectively, within 15 min of application of analyte. The detection limit in buffer is almost four decades lower than that documented for GFAP using biosensors which is is expected to pave way for advancing graphene FET based sensors towards ultrasensitive point-of-care diagnosis of GFAP, a biomarker for traumatic brain injury.

A Phenanthrenequinone-Based Ratiometric Fluorescent Probe for Rapid Detection of Peroxynitrite with Imaging in Osteoblast Precursor Cells

In the current situation, peroxynitrite (ONOO-) is drawing the increasing attention of researchers for its pivotal role in diverse pathological and physiological processes on grounds of robust oxidation and nitrification. Herein, we have successfully designed and synthesized a phenanthrenequinone benzyl borate-based chemosensor for fast and selective detection of ONOO-. The probe PTDP itself had an orange fluorescence, which was changed to strong blue fluorescence upon the addition of ONOO-, indicating the ratiometric response of the probe. This is so because of the cleavage of the benzyl boronate-protecting group of PTDP upon the addition of ONOO- with simultaneous releasing of pyridinyl-based chemosensor PPI. The PTDP showed outstanding performance in the various photophysical studies such as good selectivity, excellent sensitivity with a very low detection limit of 2.74 nM, and a very fast response time (<15 s). Furthermore, for practical applicability, it was successfully applied in the ratiometric detection of ONOO- in osteoblast precursor cells.

Disorder-to-order transition of long fibers contained in evaporating sessile drops

A liquid drop containing a long fiber is a complex system whose configuration is determined by an interplay of elastic stresses in the fiber and capillary forces due to the liquid. We study the morphological evolution of fibers that are much longer than the drop diameter in evaporating sessile drops. After insertion, the fibers are either found in an ordered or disordered state, with increasing disorder for increasing fiber length. Upon evaporation, the order increases, in such a way that the final configuration deposited on the solid surface is either a circle, an ellipse, or 8-shaped. The morphology of the deposit depends on the fiber length and the elastocapillary length, both non-dimensionalized with the characteristic drop size, which we classify in a morphology regime map. The disorder-to-order transition allows depositing ordered fiber structures on solid surfaces even in cases of a strongly disordered state after fiber insertion. Combined with technologies such as inkjet printing, this process could open new avenues to decorate surfaces with filamental structures whose morphology can be controlled by varying the fiber length.

Structural and therapeutic properties of salicylic acid-solubilized Pluronic solutions and hydrogels

Salicylic acid (SA) finds extensive applications in the treatment of rheumatic and skin diseases because of its analgesic, anti-inflammatory and exfoliating properties. As it is lipophilic in nature, there is a need for appropriate delivery systems to harness these properties for different applications. Herein, we examined the suitability of Pluronic P123/F127 micellar systems as delivery media by investigating the structural, flow and antimicrobial properties of P123/F127-SA solutions and hydrogels using DLS, SANS, rheological and zone inhibition measurement techniques. SA modulates the aggregation characteristics of these surfactant systems and brings about spherical-to-worm-like micelle-to-vesicular structural transitions in the hydrophobic Pluronic P123 system, a spherical-to-worm-like micellar transition in the mixed P123/F127 system and an onset of inter-micellar attraction in the hydrophilic Pluronic F127 system. SA-solubilized systems of both hydrophobic and hydrophilic Pluronics inhibit the growth of Gram-positive and Gram-negative bacteria with comparable MIC values. This suggests that the interaction of SA molecules with the bacterial cell membrane remains unobstructed upon encapsulation in Pluronic micelles. F127 hydrogel-based SA formulations with rheological properties suitable for topical applications and up to 15% SA loading were prepared. These will be useful SA ointments as F127 is an FDA-approved excipient for topical drug delivery applications. The results indicate that Pluronics remain effective as delivery agents for SA and exhibit interesting structural polymorphism upon its solubilization.

Pluronic Induced Interparticle Attraction and Re-entrant Liquid-Liquid Phase Separation in Charged Silica Nanoparticle Suspensions

Tuning surface properties of nanoparticles by introducing charge, surface functionalization, or polymer grafting is central to their stability and applications. Here, we show that introducing non-DLVO forces like steric and hydrophobic effects in charged silica nanoparticle suspensions through interaction with a nonionic surfactant brings about interesting modulations in their interparticle interaction and phase behavior. The Ludox TM-40 negatively charged silica suspensions thus exhibit liquid-liquid phase separation driven by the onset of interparticle attraction in the system in the presence of the triblock copolymer Pluronic P123. The observed phase separations are thermoresponsive in nature, as they are associated with lower consolute temperatures and a re-entrant behavior as a function of temperature. The nanoparticle-Pluronic system thus undergoes transformation from one-phase to two-phase and then back to one-phase with monotonic increase in temperature. Evolution of the interparticle interaction in the composite system is investigated by dynamic light scattering (DLS), small angle neutron scattering (SANS), zeta potential, rheological, and fluorescence spectroscopy studies. Zeta potential studies show that the charge interaction in the system is partially mitigated through adsorption of a Pluronic micellar layer on the nanoparticle surfaces. Contrast-matching SANS studies suggest that hydrophobic interactions between the adsorbed micellar layer bring about the onset of interparticle attraction in the system. The results are unique and not reported hitherto in charged silica nanoparticle systems.

Unusual Growth and Hydration Characteristics of Oil Solubilized Micelles in Aqueous Pluronic Systems

Lipophile induced modulations of self-assembly characteristics in aqueous Pluronic systems merit attention because of wide-ranging uses of Pluronics as solubilizing agents of lipophilic substances. In this paper, we report unusual evolutions of structural and hydration properties in lavender essential oil (LO) solubilized Pluronic P85 aqueous micellar systems as a function of micellar volume fraction and temperature. Our DLS, SANS, and viscometry studies show that the spherical-to-wormlike micellar structural transition observed in 1% P85 solutions upon solubilization of LO quite unexpectedly gets suppressed with increased P85 concentration to ≥5%. Detailed SANS studies reveal that the core sizes of the oil solubilized micelles cannot attain the threshold value required for the onset of structural transition at higher copolymer concentrations due to their progressive shrinking with an increase in P85 concentration. Oil solubilized P85 solutions show two cloud points and very interestingly exhibit micellar growth upon cooling to their lower cloud points. Steady state fluorescence studies explain this based on increasing dehydration of micellar corona with a decrease in temperature, very much opposite to what is observed in pure aqueous Pluronic systems. The results give new insight into viscous flow properties and low temperature storage possibilities of oil solubilized aqueous Pluronic systems.

Intensification patterns and the probability of HbA1c goal attainment in Type 2 diabetes mellitus: real-world evidence for the concept of 'intensification inertia'

AIMS

To assess the effects of 'clinical' and 'intensification inertia' by evaluating the impact of different intensification interventions on the probability of HbA_1c goal attainment using real-world data.

METHODS

Electronic health records (Cleveland Clinic, 2005-2016) were used to identify 7389 people with Type 2 diabetes mellitus and HbA_1c ≥53 mmol/mol (≥7.0%), despite a stable regimen of two oral antihyperglycaemic drugs for ≥6 months. The participants were stratified by index HbA_1c and analysed over a 6-month period for pharmacological intensification, and then for 12 additional months for HbA_1c goal attainment (<53 mmol/mol).

RESULTS

The probability of HbA_1c goal attainment (Kaplan-Meier analysis) in the group with index HbA_1c 53-63 mmol/mol (7.0-7.9%) was highest with the addition of oral antidiabetic drugs [57.3% (95% CI 52.1, 62.0)] or glucagon-like peptide-1 receptor agonists [56.7% (95% CI 40.4, 68.6)], in the 64-74 mmol/mol (8.0-8.9%) group with the addition of oral antidiabetic drugs [31.9% (95% CI 25.1, 38.1)] or insulin [30.6% (95% CI 18.3, 41.0)], and in the ≥75 mmol/mol (≥9.0%) group with the addition of glucagon-like peptide-1 receptor agonists [53.0% (95% CI 31.8, 67.6)] or insulin [43.5% (95% CI 36.4, 49.8)].

CONCLUSIONS

Numerical, but not statistically significant, differences in HbA_1c goal attainment probability by type of intensification were most marked in people with the highest index HbA_1c [≥75 mmol/mol (≥9.0%)]; in this group, injectable therapy showed trends toward greater glycaemic control benefits. Additional research into the phenomenon of intensification inertia is warranted.

Abstract P4-10-12: Gestational breast cancer in Singapore women

Background

Gestational breast cancer (GBC), diagnosed during pregnancy or in the first postpartum year, is expected to rise in incidence due to increasing maternal age. GBC poses unique challenges in diagnosis and treatment as clinicians seek to provide optimal treatment for these young patients without compromising neonatal outcomes. We present our retrospective findings from the first study on gestational breast cancer in Singapore.

Methods

We performed a retrospective study on 88 patients with gestational breast cancer diagnosed from April 2003 to April 2017 at three centres in Singapore. Demographic details, tumour histopathological characteristics, stage, treatment and outcomes data was collected and analysed.

Results

Eighty-eight patients were diagnosed with GBC at a median age of 35.9 years (26-43 years). Fifty (56.8%) were diagnosed intrapartum and 38 (43.2%) were diagnosed postpartum. Seventeen (19.8%) had a family history of breast cancer but none had proven BRCA mutation. Seventeen patients (19.3%) presented with stage 1, 36 (40.9%) with stage 2, 25 (28.4%) with stage 3, 5 (5.7%) with stage 4 disease. Seventeen patients underwent termination of pregnancy (27.9% of patients diagnosed during pregnancy). Seventeen (19.3%) of patients received neoadjuvant chemotherapy, 8 of whom received it during pregnancy. Forty-eight (54.5%) received adjuvant chemotherapy, 4 of whom received it during pregnancy. Two patients received palliative chemotherapy during pregnancy. Aside from one case of hearing impairment, there was no other documented neonatal complication for patients who received intrapartum chemotherapy.

The 5-year and 10-year overall survival (OS) was 80% and 66%. According to the Singapore National Cancer Registry, the 5-year OS for women younger than 44 years of age was 88.9%, therefore suggesting a lower OS in patients with GBC. The 5-year and 10 year disease-free survival (DFS) of our patients was 73% and 60% respectively. Diagnosis of cancer postpartum conferred a higher risk (hazard ratio (95%CI) 1.86 (0.55, 6.28) of mortality compared to those diagnosed intrapartum. Univariate Cox proportional hazard regression model showed that nodal positivity and clinical stage were significantly associated with DFS while only clinical stage was significantly associated with OS. Race was found to affect survival with Malay patients having a lower DFS compared to Chinese patients.

Conclusion

GBC patients in Singapore have a lower survival rate. Diagnosis of cancer postpartum confers a higher risk of mortality. This might be due to a delay in diagnosis and treatment. Malay patients have a lower survival compared to Chinese patients. Studies into genetic and social factors might shed light on how ethnicity affects survival of these patients.

Citation Format: Tan QT, Wong FY, Alcantara VS, Ganguly R, Loh KW-J. Gestational breast cancer in Singapore women [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-10-12.

Overt bleeding in complicated P. falciparum malaria: An experience from east coast of India

Delay in diagnosis of falciparum may result in complicated, life-threatening conditions. Though haematological abnormalities and coagulopathy are common complications that occur in malaria but complications with rare manifestations like overt bleeding do pose challenges for the clinicians worldwide. This study reports the incidence and prognosis of overt bleeding from the east coast of India and makes an attempt to relate it with the pathogenesis of the disease in severe Plasmodium falciparum malaria patients. This study was conducted in Sriram Chandra Bhanj Medical College Hospital, Cuttack, Odisha, India. A total of 120 complicated (multi organ dysfunction) malaria cases were included in this study. Amongst them 54 (45.0%) showed signs of overt bleeding and clinically the bleeding was either from one or multiple sites. Out of the total overt bleeding cases, 79.6% had elongated prothrombin time (PT), activated partial prothrombin time (aPTT) and elevated D-dimer with thrombocytopenia indicating disseminated intravascular coagulopathy (DIC). It was observed that case fatality rate was very high in coagulopathy group than the non coagulopathy group. Our observations highlight that awareness of overt bleeding in P. falcipatum infection is necessary for general practitioners in endemic areas for malaria like in Odisha for effective and timely management of complicated patients.Timely diagnosis and treatment of DIC with appropriate prescribed drugs can prevent and cure the complications of severe falciparum malaria with anti-malarial treatment.

Lymphocyte subtypes in relapsing-remitting multiple sclerosis patients treated with dimethyl fumarate

BACKGROUND

Recent data suggest that lymphopenia is more prevalent than reported in relapsing-remitting multiple sclerosis (RRMS) patients taking dimethyl fumarate (DMF).

OBJECTIVE

The objective of this study was to investigate the effect of DMF on lymphocyte subtypes in RRMS patients with and without lymphopenia.

METHOD

A retrospective study compared lymphocyte subtypes in DMF-treated RRMS patients with low (G1, n = 35) and normal lymphocyte counts (G2, n = 24).

RESULTS

Fifty-nine patients were identified, with mean age 49, 71.2% females, and average DMF duration 20 months. Age, sex, baseline white blood count, disease and treatment durations were similar between groups. Prior interferon therapy and baseline lower normal lymphocyte counts were more frequent in G1. Mean lymphocyte counts were 0.8 ± 0.2 × 10⁹/L in G1 and 1.6 ± 0.3 × 10⁹/L in G2. CD3⁺, CD4⁺, and CD8⁺ T cell mean counts were lower (p < 0.0001), while CD4/CD8 ratio higher (p = 0.03) in G1 than G2. Mean CD19 ⁺B cell counts were normal; however, values were lower in G1 (p = 0.04). After adjusting for confounders, significantly positive correlations were noted between lymphocyte counts and CD3 ⁺, CD4⁺, CD8⁺ T, and B cell counts. Negative correlation was observed between lymphocyte counts and CD4/CD8 ratio driven by low CD8⁺ T cell counts.

CONCLUSION

DMF treatment predominantly impacts T cells, in particular CD8⁺ subtype. This finding may have implications in this population's immunocompetence.

Clinical performance of cuffed versus uncuffed preformed endotracheal tube in pediatric patients undergoing cleft palate surgery

Background:

Uncuffed endotracheal tubes are commonly used in children but due to several decade preferred in paediatric oral surgery. Due to lack of conclusive evidences in this regard, we have conducted this study to compare post-operative morbidity following use of cuffed and uncuffed endotracheal tubes in paediatric patients undergoing cleft lip-palate surgery.

Methods:

This randomised controlled trial was conducted on children aged 2 to 12 years.110 patients were allocated in two parallel groups using computer generated list of random numbers. Post operative extubation stridor, sore throat, time to first oral intake and regaining of normal voice were compared between two groups.

Results:

The incidence of sore throat was significantly more (P value > 0.005) in patients of uncuffed group compared to cuffed group. The time to first oral intake and time to regain normal voice were significantly earlier in cuffed group compared to the other.

Conclusion:

With standard care, preformed cuffed ET tube has shown reduced incidence of post operative sore throat. Cuffed group has earlier oral intake and normal voice regain compared to uncuffed group.

Development of bis(arylimino)acenaphthene (BIAN) copper complexes as visible light harvesters for potential photovoltaic applications

Readily synthesized, new bis(arylimino)acenaphthene copper(i) complexes exhibit panchromatic light absorption to the NIR region and function in dye-sensitized solar cells.

TBP induced double cloud point in aqueous EO13PO30EO13 solutions: investigating the evolution of associated micellar characteristics as a function of temperature

TBP solubilized Pluronic L64 solutions exhibit inter-micellar attraction driven micellar cluster formation upon cooling, which is unique in non-ionic micellar systems.

Solubilization of parabens in aqueous Pluronic solutions: investigating the micellar growth and interaction as a function of paraben composition

The influence of methyl paraben (MP) and butyl paraben (BP) on the aggregation characteristics of Pluronics in an aqueous medium has been investigated by DLS, SANS, viscometry, and fluorescence measurement techniques. Parabens are extensively used as preservatives in cosmetic, pharmaceutical, and food products. In this paper, we show that their influence on the restructuring and growth of Pluronics micelles vary quite significantly with their aqueous solubility and with the composition of Pluronics. In the case of P105 and P104, MP reduces the sphere-to-rod transition temperature down to room temperature, but BP with significantly less aqueous solubility than MP suppresses such micellar transition and leads to the formation of micellar clusters due to the onset of intermicellar attractive interaction. In the case of more hydrophobic Pluronic P103, on the other hand, both MP and BP are able to induce rapid room temperature sphere-to-rod micellar growth, which is not observed in the presence of water structure making salts like NaCl and Na(3)PO(4). These observations have been attributed to modulation of growth and restructuring processes of the Pluronic micelles arising due to different locations of parabens within the micellar corona as determined by their aqueous solubility and the hydrophobicity of the Pluronics.

Regional odontodysplasia: a case of progressive tooth development

Regional odontodysplasia (RO) is considered a relatively rare dental anomaly despite increasing numbers of case reports in recent years. It usually presents as a localized anomaly in tooth development affecting a few adjacent teeth in a single maxillary or mandibular quadrant. The purpose of this paper is to describe an uncommon case of regional odotodysplasia involving noncontiguous mandibular teeth, crossing the midline in a male patient, and showing progressive normalization of tooth anatomy over a period of 6 years. Typically, teeth affected with RO become pulpally involved early on and are either extracted or endodontically treated. Such reports of automatic normalization over time in RO is supportive of a more conservative treatment approach.

Accuracy of linear measurement in the Galileos cone beam computed tomography under simulated clinical conditions

OBJECTIVES

The aim of this study was to determine the geometric accuracy of cone beam CT (CBCT)-based linear measurements of bone height obtained with the Galileos CBCT (Sirona Dental Systems Inc., Bensheim, Hessen, Germany) in the presence of soft tissues.

METHODS

Six embalmed cadaver heads were imaged with the Galileos CBCT unit subsequent to placement of radiopaque fiduciary markers over the buccal and lingual cortical plates. Electronic linear measurements of bone height were obtained using the Sirona software. Physical measurements were obtained with digital calipers at the same location. This distance was compared on all six specimens bilaterally to determine accuracy of the image measurements.

RESULTS

The findings showed no statistically significant difference between the imaging and physical measurements (P > 0.05) as determined by a paired sample t-test. The intraclass correlation was used to measure the intrarater reliability of repeated measures and there was no statistically significant difference between measurements performed at the same location (P > 0.05).

CONCLUSIONS

The Galileos CBCT image-based linear measurement between anatomical structures within the mandible in the presence of soft tissues is sufficiently accurate for clinical use.

Synchronous occurrence of anaplastic, follicular and papillary carcinomas with follicular adenoma in thyroid gland

Various combinations of thyroid carcinomas have been reported including those between different cancers of follicular cell origin and those between follicular and C-cell histogenesis. Accordingly, anaplastic carcinomas have been seen to coincide with simultaneous papillary and follicular cancers. We report a case of composite anaplastic and papillary cancer on one thyroid lobe with a follicular carcinoma in the other lobe in a female patient aged 64 years. The patient also had a separate and independent follicular adenoma in the same lobe as the composite anaplastic and papillary carcinoma. The papillary carcinoma was continuous with the anaplastic carcinoma. The findings were supported by immunohistochemistry. The patient was managed by a total thyroidectomy with bilateral modified radical neck dissection followed by chemotherapy. However, she died two months after surgery. The common follicular cell origin will explain the concurrent presence of all these cancers. This could result from the dedifferentiation of a pre-existing differentiated carcinoma.

Immunosuppression during influenza virus infection

The effects of a live attenuated influenza vaccine and subsequent challenge with virulent influenza virus on the delayed hypersensitivity skin test, and the in vitro response of lymphocytes were evaluated. Volunteers were skin tested before and after administration of vaccine or placebo and challenge with PPD (a purified protein derivative of Mycobacterium tuberculosis), candida, mumps, and trichophytin, and their lymphocytes were tested for [(3)H]thymidine uptake in response to phytohemagglutin. Of eight volunteers who showed evidence of viral replication after administration of the attenuated vaccine, four had a significant diminution in their skin test response, whereas 8 of 13 volunteers infected with virulent influenza virus showed a diminution. Of the 21 volunteers who were infected with either attenuated or virulent influenza virus, 12 showed suppression of their phytohemagglutin response. None of the volunteers who were given placebo vaccine, or who showed no evidence for viral replication after immunization or challenge, had a suppression of their skin test or phytohemagglutin responses. Although most of the infected volunteers demonstrated suppression of their T-cell function, there was no evidence of a similar suppression of B-cell function.

Functional analysis of the cis-acting elements responsible for the induction of the Cyp6a8 and Cyp6g1 genes of Drosophila melanogaster by DDT, phenobarbital and caffeine

Many Drosophila cytochrome P450 or Cyp genes are induced by caffeine and phenobarbital (PB). To understand the induction mechanism, we created Drosophila S2 cell lines stably transformed with different luciferase reporter plasmids carrying upstream DNAs of Cyp6a8 allele of the resistant 91-R strain, and the 1.1-kb upstream DNAs of Cyp6g1 of the 91-R and the susceptible 91-C strains. Following 24 h treatment with dichlorodiphenyltrichloroethane (DDT), caffeine or PB, luciferase activity of all cell lines was determined. Results showed that the 0.1-kb DNA of Cyp6a8 and the upstream DNAs of Cyp6g1 from both strains are not induced by these chemicals in S2 cells. However, the 0.2-, 0.5- and 0.8-kb DNAs of Cyp6a8 showed 13-24-, 4-5- and 2.2-2.7-fold induction with caffeine, PB and DDT, respectively. These DNAs also showed a 2-3-fold synergistic effect of caffeine and PB but not of caffeine and DDT. The results suggest that the cis-regulatory elements for all three chemicals are located within the -11/-199 DNA of Cyp6a8. Furthermore, caffeine and PB inductions appear to be mediated via different cis-elements, whereas caffeine and DDT induction may involve common regulatory elements. These stably transformed cell lines should help understand the mechanism of resistance-associated Cyp gene overexpression in Drosophila.

Alteration of brain monoamines & EEG wave pattern in rat model of Alzheimer's disease & protection by Moringa oleifera

BACKGROUND & OBJECTIVES

The monoaminergic systems which exert a modulatory role in memory processing, are disturbed in Alzheimer's disease (AD) and Moringa oleifera (MO) has been shown to exert its effect in CNS by altering the brain monoamines. The present study aims to see whether chronic oral treatment of ethanolic extract of MO leaves can alter the brain monoamines (norepinephrine, dopamine and serotonin) in distinct areas of brain in rat model of AD caused by intracerebroverticle (ICV) infusion of colchicine and hence can provide protection against monoaminergic deficits associated with AD.

METHODS

Rats were given ICV infusion of colchicine (15 microg/5microl) and MO leaf alcoholic extract was given in various doses. The effective dose was standardized by radial arm maze (RAM) training. From the selected dose of 250 mg/kg body weight, the biochemical estimations and EEG studies were performed.

RESULTS

Stereotaxic ICV infusion of colchicine significantly impaired the RAM performance together with decrease in norepinephrine (NE) level in cerebral cortex (CC), hippocampus (HC) and caudate nucleus (CN). Dopamine (DA) and serotonin (5-HT) levels were decreased in CC, HC and CN. The EEG studies showed a decrease in beta and alpha waves and increase in biphasic spike wave pattern in experimental Alzheimer rat model. Treatment with MO extract markedly increased the number of correct choices in a RAM task with variable alteration of brain monoamines. The EEG studies showed an increase in beta waves and a decrease in spike wave discharges.

INTERPRETATION & CONCLUSION

Our results showed that brain monoamines were altered discreetly in different brain areas after colchicine infusion in brain. After treatment with MO, leaf extract the monoamine levels of brain regions were restored to near control levels. Our findings indicated that MO might have a role in providing protection against AD in rat model by altering brain menoamine levels and electrical activity.

Room temperature sphere-to-rod growth and gelation of PEO–PPO–PEO triblock copolymers in aqueous salt solutions

The effects of NaCl and KF on the sphere-to-rod micellar growth behavior of triblock copolymers having two different compositions, (EO)20(PO)70(EO)20 (P123) and (EO)26(PO)40(EO)26 (P85), have been studied by dynamic light scattering (DLS), small angle neutron scattering (SANS) and dilute solution viscometry. NaCl can effectively tune the sphere-to-rod growth temperature of the micelles of both these copolymers and induce micellar growth down to the room temperature and below. The growth behavior is found to be dependent on the composition of the copolymer as P123 being more hydrophobic shows the room temperature growth in the presence of ethanol at significantly lesser NaCl concentration than the less hydrophobic copolymer P85. DLS studies depict for the first time the growth driven transition of the copolymer solutions from dilute to semi-dilute regime as a function of copolymer and salt concentrations. KF can also induce room temperature growth of the P123 micelles at lesser salt concentration than NaCl but it fails to induce any such growth of the P85 micelles. A pseudo-binary temperature-concentration phase diagram on 15% copolymer solutions shows the variation of the sphere-to-rod transition temperature and the cloud point of the copolymer solutions as a function of salt concentration.

Mathematical model for chemotherapeutic drug efficacy in arresting tumour growth based on the cancer stem cell hypothesis

OBJECTIVE

Cancer stem cells have been identified as the growth root for various malignant tumours and are thought to be responsible for cancer recurrence following treatment.

MATERIALS AND METHODS

Here, a predictive mathematical model for the cancer stem cell hypothesis is used to understand tumour responses to chemotherapeutic drugs and judge the efficacy of treatments in arresting tumour growth. The impact of varying drug efficacies on different abnormal cell populations is investigated through the kinetics associated with their decline in response to therapy.

RESULTS AND CONCLUSIONS

The model predicts the clinically established 'dandelion phenomenon' and suggests that the best response to chemotherapy occurs when a drug targets abnormal stem cells. We compare continuous and periodic drug infusion. For the latter, we examine the relative importance of the drug cell-kill rate and the mean time between successive therapies, to identify the key attributes for successful treatment.

Effect of dietary hempseed intake on cardiac ischemia-reperfusion injury

Polyunsaturated fatty acids (PUFAs) have significant, cardioprotective effects against ischemia. Hempseed contains a high proportion of the PUFAs linoleic acid (LA) and alpha-linolenic acid (ALA), which may have opposing effects on postischemic heart performance. There are no reported data concerning the cardiovascular effects of dietary hempseed intake. A group of 40 male Sprague-Dawley rats were distributed evenly into four groups that were fed for 12 wk a normal rat chow supplemented with hempseed (5% and 10%), palm oil (1%), or a 10% partially delipidated hempseed that served as a control. Plasma ALA and gamma-linolenic acid levels were significantly elevated in the rats that were fed a 5% or 10% hempseed-supplemented diet, but in heart tissue only ALA levels were significantly elevated in the rats fed these diets compared with control. After the dietary interventions were completed, postischemic heart performance was evaluated by measuring developed tension, resting tension, the rates of tension development and relaxation, and the number of extrasystoles. Hearts from rats fed a hempseed-supplemented diet exhibited significantly better postischemic recovery of maximal contractile function and enhanced rates of tension development and relaxation during reperfusion than hearts from the other groups. These hearts, however, were not protected from the occurrence of extrasystoles, nor were the increases in resting tension altered during ischemia or reperfusion as a function of any dietary intervention. Our data demonstrate that dietary hempseed can provide significant cardioprotective effects during postischemic reperfusion. This appears to be due to its highly enriched PUFA content.

Effect of SDS on the Self-Assembly Behavior of the PEO−PPO−PEO Triblock Copolymer (EO)20(PO)70(EO)20

The mixed micellar system comprising the poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)-based triblock copolymer (EO)(20)(PO)(70)(EO)(20) (P123) and the anionic surfactant sodium dodecyl sulfate (SDS) has been investigated in aqueous media by small-angle neutron scattering (SANS) and viscosity measurements. The aggregation number of the copolymer in the micelles decreases upon addition of SDS, but a simultaneous enhancement in the degree of micellar hydration leads to a significant increase in the micellar volume fraction at a fixed copolymer concentration. This enhancement in the micellar hydration leads to a marked increase in the stability of the micellar gel phase until it is destroyed at very high SDS concentration. Mixed micellar systems with low and intermediate SDS concentrations form the micellar gel phase in much wider temperature and copolymer concentration ranges than the pure copolymer micellar solution. A comparison of the observed results with those for the copolymers (EO)(26)(PO)(40)(EO)(26) (P85) and (EO)(99)(PO)(70)(EO)(99) (F127) suggests that the composition of the copolymers plays a significant role in determining the influence of SDS on the gelation characteristics of the aqueous copolymer solutions. Copolymers with high PO/EO ratios show an enhancement in the stability of the gel phase, whereas copolymers with low PO/EO ratios show a deterioration of the same in the presence of SDS.

Mathematical model for the cancer stem cell hypothesis

Recent research on the origin of brain cancer has implicated a subpopulation of self-renewing brain cancer stem cells for malignant tumour growth. Various genes that regulate self-renewal in normal stem cells are also found in cancer stem cells. This implies that cancers can occur because of mutations in normal stem cells and early progenitor cells. A predictive mathematical model based on the cell compartment method is presented here to pose and validate non-intuitive scenarios proposed through the neural cancer stem cell hypothesis. The growths of abnormal (stem and early progenitor) cells from their normal counterparts are ascribed with separate mutation probabilities. Stem cell mutations are found to be more significant for the development of cancer than a similar mutation in the early progenitor cells. The model also predicts that, as previously hypothesized, repeated insult to mature cells increases the formation of abnormal progeny, and hence the risk of cancer.

The effects of dietary hempseed on cardiac ischemia/reperfusion injury in hypercholesterolemic rabbits

BACKGROUND

Hempseed is a novel functional food that contains several health-promoting polyunsaturated fatty acids (PUFAs). PUFAs, such as those found in flaxseed and fish, have been shown to protect the heart against arrhythmias following ischemia/reperfusion.

OBJECTIVE

TO INVESTIGATE THE POTENTIAL OF DIETARY HEMPSEED AS A CARDIOPROTECTIVE AGENT AGAINST GLOBAL ISCHEMIA AND SUBSEQUENT REPERFUSION BY ASSESSING SEVERAL MEASUREMENTS OF CARDIAC PERFORMANCE: QT interval duration, left ventricular pressure, arrhythmia incidence and arrhythmia duration.

METHODS

MALE NEW ZEALAND WHITE RABBITS WERE FED ONE OF SIX DIETS: a control diet; or one supplemented with 10% hempseed, 10% delipidated hempseed, 0.5% cholesterol, 0.5% cholesterol plus 10% hempseed or 5% coconut oil. After eight weeks on their respective diets, the hearts were excised and subjected to 30 min of global ischemia and 45 min of reperfusion. Electrocardiogram traces were recorded throughout the experiment and were subsequently analyzed for QT interval duration, left ventricular pressure, arrhythmia incidence and arrhythmia duration. Plasma and cardiac tissue were analyzed for fatty acid content and composition.

RESULTS

Cholesterol-fed animals exhibited significantly higher PUFA levels in their plasma, but this did not directly translate into higher PUFA levels in their cardiac fractions. There were no significant differences among the groups in the incidence or duration of ischemia-derived arrhythmias. During reperfusion, there was a significant decrease in the incidence of fibrillation in the hearts obtained from cholesterol-fed and hempseed- plus cholesterol-fed rabbits compared with the hearts from delipidated hempseed-fed rabbits.

CONCLUSIONS

Dietary hempseed induced limited beneficial effects on cardiac function during ischemia/reperfusion challenge. The present study does not support the use of dietary hempseed to protect the heart during ischemic insult in this experimental model.

Effect of “inverse melting transition” of aqueous triblock copolymer solutions on solute rotational dynamics

Rotational dynamics of two structurally similar hydrophobic solutes, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and 1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DPP), has been investigated in 30% wv aqueous solution of triblock copolymer, poly(ethylene oxide)(20)-poly(propylene oxide)(70)-poly(ethylene oxide)(20) as a function of temperature. This study has been undertaken in an attempt to explore how the dynamics of a solute molecule solubilized in a copolymer solution is influenced when it undergoes sol-to-gel transition. It has been observed that the anisotropy decays of both DMDPP and DPP can be described by biexponential functions in the sol as well as in the gel phase. This observation has been rationalized on the basis of the probe molecule undergoing two different kinds of motion rather than being located in two different regions of the micelle. Even in the gel phase, which results as a consequence of micelle-micelle entanglement due to an increase in their volume fraction, the rotational relaxation of the solutes is similar to that observed in the micellar solution. The outcome of this work indicates that even though these gels have very high macroscopic viscosities and hence do not flow, the microenvironments experienced by the solutes are akin to that of a micellar solution.