Initial experience of TAS-102 chemotherapy in Australian patients with Chemo-refractory metastatic colorectal cancer

For patients with refractory metastatic colorectal cancer (mCRC) treatment with Trifluridine/Tipiracil, also known as TAS-102, improves overall survival. This study aims to investigate the efficacy and safety of TAS-102 in a real-world population from Victoria, Australia. A retrospective analysis of prospectively collected data from the Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) registry was undertaken. The characteristics and outcomes of patients receiving TAS-102 were assessed and compared to those enrolled in the registration study (RECOURSE). Across 13 sites, 107 patients were treated with TAS-102. The median age was 60 years (range: 31-83), compared to 63 for RECOURSE. Comparing registry TAS-102-treated and RECOURSE patients, 75% vs 100% were ECOG performance status 0-1, 74% vs 79% had initiated treatment more than 18 months from diagnosis of metastatic disease and 36% vs 49% were RAS wild-type. Median time on treatment was 10.4 weeks (range: 1.7-32). Median progression-free survival (PFS) was 3.3 months compared to 2 months in RECOURSE, while median overall survival was the same at 7.1 months. Two patients (2.3%) had febrile neutropenia and there were no treatment-related deaths, where TAS-102 dose at treatment initiation was at clinician discretion.TRACC registry patients treated with TAS-102 were younger than those from the RECOURSE trial, with similar overall survival observed. Less strict application of RECIST criteria and less frequent imaging may have contributed to an apparently longer PFS.

Management of intermittent claudication: the importance of secondary prevention

Atherosclerotic peripheral arterial disease (PAD) is a common disorder usually associated with silent or symptomatic arterial disease elsewhere in the circulation and a cluster of cardiovascular risk factors inducing atheroma progression and/or thrombotic complications. Because of these strong clinical associations, especially with coronary heart disease, the ankle-brachial pressure index (ABPI) is of prognostic significance. The clinical management of IC should include relief of symptoms combined with prevention of secondary cardiovascular complications, e.g. acute thrombotic events causing limb- or life-threatening ischaemia, which are often due to atherosclerotic plaque rupture leading to thrombotic vessel occlusion. Many patients with PAD do not receive an optimum package of secondary prevention, tailored to include maximum cholesterol reduction, BP and glycaemic control, ACE inhibition and single or combination anti-platelet therapy. This review considers recent information from large secondary prevention trials, e.g. the PAD subgroups within the HOPE, CAPRIE and statin studies. Slowing progression of atherosclerosis, and inducing stabilisation and regression of atheromatous plaques, is now feasible using long-term combination drug therapy. The phrase angle quotation mark, leftangle quotation mark, leftconservative therapyangle quotation mark, rightangle quotation mark, right, popular among vascular surgeons, implies a passive minimal-intervention strategy of surveillance and lifestyle advice; such terminology is perhaps no longer appropriate since considerable improvements in survival are likely to accrue if all patients with PAD, especially those with low ABPI, receive vigorous, titrated medical therapies, tailored to individual patients, as part of an evidence-based secondary prevention regime.

Coordinated expression of Hoxa2, Hoxd1 and Pax6 in the developing diencephalon

Coordinated expression of Hoxa2, Hoxd1 and Pax6 proteins were found to coincide with the three developmental stages of the diencephalon, as described for the mouse brain. In the first stage (embryonic day (E) 10-12) Hoxa2, Hoxd1 and Pax6 (an early marker gene of the diencephalon) were expressed as early as E10.5 in prosomeres (p), p2 and p3. All three proteins continue to exhibit overlapping domains of expression at E12.5-13 (beginning of the second stage) when the primitive dense cell layer begins to differentiate into the internal germinal, external germinal and mantle layers. Towards the end of the second stage (E15), Pax6 expression was down-regulated whereas Hoxa2 and Hoxd1 continued to exhibit overlapping domains of expression for both protein and mRNA. Hoxd1 expression decreased significantly in the third stage of diencephalic development (E16-postnatal) such that only Hoxa2 expression persisted in the diencephalon of newborn mice. The temporal and spatial expression of these three proteins imply that coordinated waves of Hoxa2, Hoxd1 and Pax6 expression may be required to provide positional information for the specification of the diencephalon.

Surface plasmon resonance-based immunoassays

Surface plasmon resonance (SPR) has been successfully incorporated into an immunosensor format for the simple, rapid, and nonlabeled assay of various biochemical analytes. Proteins, complex conjugates, toxins, allergens, drugs, and pesticides can be determined directly using either natural antibodies or synthetic receptors with high sensitivity and selectivity as the sensing element. Immunosensors are capable of real-time monitoring of the antigen-antibody reaction. A wide range of molecules can be detected with lower limits ranging between 10(-9) and 10(-13) mol/L. Several successful commercial developments of SPR immunosensors are available and their web pages are rich in technical information. This review highlights many recent developments in SPR-based immunoassay, functionalizations of the gold surface, novel receptors in molecular recognition, and advanced techniques for sensitivity enhancement. Furthermore, it describes the challenge of current problems and provides some insights toward the future technologies.

Criteria to determine food allergen priority

The emergent health issue of food allergens presents an important challenge to the food industry. More than 170 foods have been reported in the scientific literature as causing allergic reactions. Clearly, it would be impossible to deal with the presence of trace amounts of all these in the context of food labeling. If the decision to classify major allergens is based solely on the knowledge and experience of allergists and food scientists in the field, without scientifically defined criteria, it is likely to lead to a proliferation of lists. Such practices may lead to an unnecessary elimination of foods containing important nutrients. This paper defines food allergy, food intolerance, and food anaphylaxis and identifies criteria for classifying food allergens associated with frequent allergic reactions. A practical list of food allergens that may result in potentially life-threatening allergic reactions is provided. A mechanism-based (i.e., immunoglobulin E mediated), acute life-threatening anaphylaxis that is standardized and measurable and reflects the severity of health risk is proposed as the principal inclusion criterion for food allergen labeling. Where available, prevalence in the population and threshold levels of allergens should be used as an additional guide to identify possible future labeling needs.

Determination of egg proteins in food products by enzyme immunoassay

An enzyme-linked immunosorbent assay (ELISA) was developed to determine the presence of egg proteins in foods. The polyclonal antibodies developed were specific to whole egg proteins and did not cross-react with any of the 38 nuts, legumes, or other common food ingredients tested. The concentrations of egg proteins that will inhibit 50% of antibody-antigen binding, IC50, were 3-7 ng/mL, and the linear range was 0.5-62.5 ng/mL. The detection limit was 0.2 ppm for various foods. Recoveries ranged from 67 to 96%. The intra- and inter-assay coefficients of variation in this procedure were 10-13% for ice cream spiked at 0.8 and 1.6 ppm. The ELISA has been applied to ice creams, noodles, pasta, and breads. Egg proteins were identified in all declared egg products, and no false positives were found.

Immunoassay of fumonisins by a surface plasmon resonance biosensor

A surface plasmon resonance (SPR) immunosensor is developed to determine concentrations of the mycotoxin, fumonisin B1 (FB1), in spiked samples. Polyclonal antibodies produced against FB1 are adsorbed onto a thin gold film substrate, which is coupled to a glass prism in the Kretschmann configuration. The output beam of a planar light-emitting diode is focused through the prism to excite SPR at the surface of the gold film. When a sample containing FB1 is added to a cell on the outside of the gold film, the angular profile of reflected light intensity shifts. This changes the resonance angle and the reflected beam intensity at a selected angle, both of which are proportional to the FB1 concentration. After optimization of the antibody overlayer, a detection limit of 50 ng/mL is obtained for the direct assay with an analysis time under 10 min. Multiple sample additions and large-volume sample circulation can be used with the high-affinity antibodies to achieve lower detection limits.

Evaluation of enzyme-linked immunosorbent assay for analysis of beer for fumonisins

A recently developed sensitive indirect competitive enzyme-linked immunosorbent assay (ELISA) was applied to the determination of fumonisins in beer. Intra-assay and inter-assay recoveries averaged 98.7-102.8% at added fumonisin B1 (FB1) levels of 0.5-50 ng/ml beer, and coefficients of variation were 2.8-4.4 and 4.7-8.6%, respectively. Cross-reactivity of fumonisin B2 (FB2) compared with FB1 averaged 67% in beer. Two experiments were carried out to compare ELISA with liquid chromatography (LC) for determination of fumonisins in beer. In the first experiment, 19 samples (five previously known positive, nine other samples and five spiked samples) were passed through commercial immunoaffinity columns (ICs) and analysed by LC before conducting blind ELISA determinations on the extracts and beers directly. The known positive beers and extracts were used as blind duplicates. The second comparative experiment screened 46 beer samples by ELISA and then 22 positive and three of the negative samples were analysed by LC; the highest level found was 64.3 ng total fumonisins/ml measured by LC (24.7 ng/ml by ELISA). Regression analyses showed good correlation between ELISA and LC in the first experiment but low level interferences (equivalent to up to 5.35 ng fumonisin/ml) were observed by ELISA in the IC extracts. Five of nine beers negative by LC showed < 1 ng/ml ELISA responses on direct beer analysis. The second comparative experiment indicated underestimation by ELISA. However, there were two samples which tested positive by ELISA (0.2 ng/ml) but were found negative by LC (results close to the detection limits of both methods, which were 0.1 or 0.2 ng/ml by ELISA and 0.1-0.15 ng each fumonisin/ml by LC). There were no false negatives. It is concluded that ELISA has considerable value in rapid screening of beer directly for fumonisins.

Fumonisin B1 induces protein kinase C translocation via direct interaction with diacylglycerol binding site

Fumonisins are carcinogenic to rats and are suspected human carcinogens. However, the mechanism(s) of carcinogenesis of fumonisn B1 (FB1) is poorly understood. Multiple signal transduction pathways such as protein kinase C (PKC) have been shown to play an important role in carcinogenesis. This study was undertaken to evaluate whether FB1 affects PKC activation. Similar to tumor-promoting phorbol ester, phorbol 12-myristate-13-acetate (PMA), PKC is also catalytically activated by FB1. Protein kinase C activity and its redistribution in response to FB1 were determined in rat cerebrocortical slices. Cytosolic and membranous PKC activities were determined by histone phosphorylation in the presence of [gamma-32P]ATP, phosphatidyl-L-serine, PMA, and Ca2+. Distribution of gamma PKC isozyme in the presence of FB1 was also assessed by immunoblotting using affinity purified anti-peptide antibodies. Similar to PMA, FB1 added in vitro to rat cerebrocortical slices facilitated PKC translocation from cytosol to membrane in a concentration-dependent manner. This FB1-induced PKC translocation was inhibited by incubation with the inactive 4 alpha-phorbol 12,13-didecanoate. The effects of FB1 and PMA were neither additive nor synergistic. In addition, PMA and FB1-induced PKC enzyme redistribution were inhibited by pretreating tissues with sphingosine. A concentration-related FB1 attenuation of specific phorbol dibutyrate, [3H]PDBu, binding was also observed when cortical membranes were incubated with either PMA or sphingosine. This is the first report of FB1-induced PKC translocation via a direct action on the diacylglycerol site that also binds phorbol esters. Because phorbol esters are well known tumor promoters, we provide a plausible cellular mechanism to explain the carcinogenicity of FB1.

Enzyme immunoassay for determination of peanut proteins in food products

Food allergy presents a problem for many parts of society, including sensitive subjects, schools, health authorities, and the food industry. Once food allergy is diagnosed, dietary avoidance is the principle method of management. Because trace levels of peanuts can elicit an adverse to fatal reaction, unintentional exposure to the offending allergens may have devastating consequences to sensitive individuals. However, determination of trace amounts of unintentional peanut contamination in our food supply is very difficult. Recently, we developed polyclonal antibodies specific to peanut proteins that do not cross-react with 22 legumes, tree nuts, or other common snack ingredients. An antiserum containing the polyclonal antibodies was used to develop a sensitive enzyme-linked immunosorbent assay (ELISA) for determination of peanut proteins in snack foods. This study reports the first successful ELISA test to detect trace amounts of peanut allergens in a variety of foods. The concentration of peanut protein that inhibited 50% of antibody-antigen binding (IC50) was 12 ng/mL, the linear range was 1-63 ng/mL, and the detection limit was 400 ng/g (ppb) for the various foods tested. Recoveries ranged from 68 to 90%, with coefficients of variation of 2-22%, depending on the commodity. Using this new procedure, allergy-related complaint samples from various food groups were analyzed, and undeclared peanut proteins were identified in some products.

Biological fate of fumonisin B1 in food-producing animals

The presence of mycotoxins in grains and feedstuffs causes not only animal health problems, but also a valid concern about the transmission of potentially toxic residues into animal-derived products intended for human consumption. In a series of studies at Agriculture and Agri-Food Canada, we investigated the biological fate of fumonisin B1 (FB1) in several food-producing animals (grower pigs, laying hens, dairy cattle), as well as monitored various parameters for evidence of toxicity in these species. In several experiments involving either single-dose protocols (iv, po) or longer-term feeding trials, the pharmacokinetic profiles of FB1 (purity > 95%) in these species were determined, including tissue accumulation and transmission of residues. Toxicological (and economical) implications such as performance (feed consumption, growth), productivity, and carcass quality were also measured when appropriate.

Prenatal cocaine exposure selectively reduces mesocortical dopamine release

The effect of prenatal exposure to cocaine on the release of [3H]dopamine and on presynaptic dopamine autoreceptor regulation of [3H]dopamine release in prelabeled frontal cortical, cingulate cortical and striatal slices was investigated. The release of [3H]dopamine that is evoked by high K+ was reduced by 20 to 28% in the cortical regions but not in striatum. This effect was observed at 10 days of age and persisted up to postnatal day 120 in rabbits that were exposed to cocaine during gestational days 8 to 29. Spontaneous [3H]dopamine release was increased by 18 to 22% in frontal and cingulate cortices but not in striatum of the 10- but not the 50- or 120-day-old rabbit that was exposed to cocaine during gestational days 8 to 29. Total [3H]dopamine accumulated in brain slices examined on postnatal days 10, 50 or 120 was not affected by prenatal cocaine exposure. Incubation of slices with dopamine dose-dependently inhibited K(+)-evoked [3H]dopamine release in both cortical and striatal slices. Prenatal cocaine exposure enhanced the responsiveness to in vitro dopamine in the two cortical regions but not in striatum. Fetal cocaine exposure did not affect the levels of dopamine or its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, in frontal cortex or striatum. Similarly, no apparent differences in dopamine metabolism, as indicated by the ratio of 3,4-dihydroxyphenylacetic acid + homovanillic acid/dopamine, were observed in these brain areas. These findings demonstrate that prenatal cocaine exposure selectively affects depolarization-evoked [3H]dopamine release and its regulation by presynaptic dopamine autoreceptor in cortical areas.(ABSTRACT TRUNCATED AT 250 WORDS)

Survey of total tetrahydrophthalimide in baby foods using both enzyme-linked immunosorbent assay and gas chromatography/mass spectrometry: a comparative study

An enzyme-linked immunosorbent assay (ELISA) method was compared with a gas chromatographic/mass spectrometric (GC/MS) method for determining the concentration (in parts per million) of the combination of captan and its degradation product tetrahydrophthalimide (THPI) in 13 fruit samples and in a survey of baby foods. Ninety baby foods (49 fruits, 28 juices, and 13 vegetables) from 2 different suppliers were sampled. All captan in the samples was converted to THPI before each analysis. None of the samples contained a concentration of combined captan and THPI that violated the maximum residue limit of 5.0 ppm. Eight samples of baby food tested positive for THPI at levels ranging from 0.019-0.041 ppm by the GC/MS method, whereas 20 samples tested positive in the ELISA assay. All samples that tested positive with the GC/MS method also tested positive with the ELISA method. Thirteen percent of the baby food samples tested false positive with the ELISA method. The ELISA assay also gave higher values than the GC/MS method. The ELISA method can be effectively used as a primary screening tool to select samples testing positive for THPI. The concentration of THPI in these samples can then be verified using the GC/MS method.

Development of enzyme immunoassay for captan and its degradation product tetrahydrophthalimide in foods

A simple, sensitive, and precise enzyme-linked immunosorbent assay (ELISA) is described for the quantitation of captan as its degradation product tetrahydrophthalimide (THPI) in foods using polyclonal antibodies. Three hapten analogues of THPI with different alkyl spacer arm lengths were synthesized. Immunogens and coating proteins were prepared by coupling these haptens to human serum albumin and ovalbumin, respectively. A 5-carbon spacer arm appeared to be optimum for the production of antibodies. Heterologous coating proteins did not improve the sensitivity, but reduction of homologous coating protein concentration did improve the sensitivity, resulting in a concentration of test compound required to inhibit binding by 50% of 15.5 ng/mL. The antiserum is specific for captan, captafol, and THPI, but not other structurally related compounds. The minimum detection limit was 1 ng/mL; the linearity was 1-200 ng/mL. The overall recoveries of captan and THPI from 11 commodities spiked at 4 levels were 92 and 100%, respectively. The intra-assay and interassay coefficients of variation were 9.1 and 16.8% for apple blanks and 5.9 and 4.2% for apple spiked with 3 ppm THPI, respectively. The ELISA described is suitable for measuring captan and THPI at levels comparable to those typically found in fruit.

Effects of the antidepressant phenelzine on brain levels of gamma-aminobutyric acid (GABA)

Time- and dose-response studies were carried out on the effects of the monoamine oxidase-inhibiting antidepressant and antipanic drug phenelzine on GABA levels in rat whole brain. At a dose of 15 mg/kg i.p., phenelzine significantly elevated GABA levels at all time intervals studied (1, 2, 4, 8, 16, and 24 h). A further investigation indicated that this was a dose-dependent effect. The possible importance of GABA in the etiology and pharmacotherapy of depression and panic disorder is discussed.

Metabolism of N,N-diethyl-m-toluamide (DEET) by liver microsomes from male and female rats. Simultaneous quantitation of DEET and its metabolites by high performance liquid chromatography

A simple and sensitive HPLC procedure was developed to separate and quantitate N,N-diethyl-m-toluamide (DEET) and its in vitro metabolites using a gradient elution, a reversed phase C18 column, and an internal standard. This procedure was applied to examine the metabolism of this insect repellent in liver microsomes from normal (untreated) male and female Wistar rats. At a pH of 8.6 and at a substrate concentration of 200 microM, the microsomal preparations from males degraded DEET faster than did those from females. The half-life of DEET was 10 min and 15 min, respectively. The benzylic methyl hydroxylated metabolite and the N-deethylated metabolite were determined over 2 hr in fortified microsomal suspensions. Rate constants for appearance of the metabolites showed significantly higher values for males than for females. These observations suggests that a sex difference may be present in the metabolism of DEET.

Analysis of the antidepressant phenelzine in brain tissue and urine using electron-capture gas chromatography

A novel gas chromatographic method for the analysis of the antidepressant phenelzine has been developed. The procedure involves extraction with a liquid ion-pairing compound, back-extraction with HCl, basification, and derivatization with pentafluorobenzoyl chloride. The dipentafluorobenzoyl derivative (structure confirmed by mass spectrometry) is separated and analyzed on a gas chromatograph equipped with a fused silica capillary column and an electron-capture detector. The procedure has been utilized for quantitation of phenelzine in brain of phenelzine-treated rats and in urine from human subjects receiving phenelzine.

Synthesis of N-(3,6-dihydro-1(2H)-pyridinyl)benzamides with hyperglycemic-hypoglycemic activity

A group of N-(3,6-dihydro-1(2H)-pyridinyl)benzamides 7 were synthesized to determine the effect that the position and physicochemical properties of substituents attached to the heterocyclic ring have on blood glucose levels. 5-Methyl-N-(3,6-dihydro-1(2H)-pyridinyl)benzamide 7b was the most active hyperglycemic agent, elevating blood glucose 124% and 116% at 2 and 4 h, respectively, after a 100 mg/kg po dose. The most active hypoglycemic agent was the 4-acetyl analogue 7o, which was about 50% as active as chlorpropamide, lowering blood glucose 19% at 4 h after a 100 mg/kg po dose. A correlation between blood glucose levels and the partition coefficient P was not observed.

Rapid analysis of beta-phenylethylamine in tissues and body fluids utilizing pentafluorobenzoylation followed by electron-capture gas chromatography

A rapid, sensitive gas chromatographic procedure for analysis of beta-phenylethylamine is reported. The procedure involves extraction with a liquid ion-pairing compound, back-extraction with HCl, basification and reaction with pentafluorobenzoyl chloride under aqueous conditions. The pentafluorobenzoyl derivative of beta-phenylethylamine is then separated and analyzed on a gas chromatograph equipped with a capillary column and an electron-capture detector. The procedure produces a derivative which has good chromatographic properties and a high degree of stability. The method has been applied to analysis of beta-phenylethylamine in a variety of tissues and body fluids.

Simple automated gas chromatographic analysis of amino acids and its application to brain tissue and urine

The separation of 21 free amino acids as their isobutyl N(O,S)-pentafluorobenzoyl derivatives by capillary gas chromatography with electron-capture detection is described. This method has been successfully applied to routine analysis of most of these amino acids in brain tissue and urine. The amino acids are converted to their isobutyl N(O,S)-pentafluorobenzoyl derivatives by acid-catalysed esterification followed by aqueous extractive pentafluorobenzoylation. The 21 amino acids can be separated on a single capillary column in 21 min. The high sensitivity permits analysis in minute quantities of sample and the high stability permits the use of an automatic sample injector at ambient temperatures. Thus, over 50 samples can be readily analyzed in a single day.

Synthesis of N-[[(substituted-phenyl)carbonyl]amino]-1,2,3,6-tetrahydropyridines with analgesic and hyperglycemic activity

A group of N-[(phenylcarbonyl)amino]1-2,3,6-tetrahydropyridines, 5, were synthesized to determine the effect that changes in aromatic substitution on the phenyl ring have on analgesic, hyperglycemic, and antiinflammatory activities. All of the N-[(phenylcarbonyl)amino]-1,2,3,6-tetrahydropyridines 5 exhibited potent analgesic activity, relative to morphine, irrespective of the position and physicochemical properties of the aromatic substituent. Pretreatment with naloxone did not alter the analgesic activity of the 4-fluorophenyl derivative 5P. N-[[(2-Fluorophenyl)-carbonyl]amino]-1,2,3,6-tetrahydropyridine (5n) was one of the most active hyperglycemic agents, elevating blood glucose 213 and 127% at 2 and 4 h after a 100 mg/kg po dose. Incorporation of aromatic substituents into the 3 and 4 positions of 1 abolished antiinflammatory activity.

Synthesis of N-(carbonylamino)-1,2,3,6-tetrahydropyridines with analgesic, antiinflammatory, and hyperglycemic activity

A group of N-(carbonylamino)-1,2,3,6-tetrahydropyridines was synthesized to investigate the effects that changes in functionality at the carbonyl group have on analgesic, antiinflammatory, and hyperglycemic activities. One of the most active analgesic compounds was N-[(ethoxycarbonyl)amino]-1,2,3,6-tetrahydropyridine (5o), which was comparable to that of morphine. Pretreatment with naloxone did not alter the activity of 5o or 5q. N-[(2-Furanylcarbonyl)amino]-1,2,3,6-tetrahydropyridine (5q) was the most potent hyperglycemic agent, elevating blood glucose 181% at 2 and 4 h after a 100 mg/kg po dose.