Publications by authors named "Chappel C"

Article Synopsis
  • A gas chromatography-mass spectrometry (GC-MS) assay was developed to measure plasma oxalate levels, specifically designed for pediatric patients with primary hyperoxaluria.
  • The method included a thorough validation process, revealing a detection limit of 0.78 μmol/L and a linear range up to 80.0 μmol/L, with acceptable precision and recovery rates.
  • Results indicated that while specific cut-off values help differentiate primary from non-primary hyperoxaluria, plasma oxalate levels can be influenced by various factors like sample preparation and medications, highlighting the need for clinical context in interpretation.
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Introduction: The LumiraDx severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen test, which uses a high-sensitivity, microfluidic immunoassay to detect the nucleocapsid protein of SARS-CoV-2, was evaluated for diagnosing acute coronavirus disease 2019 (COVID-19) in adults and children across point-of-care settings (NCT04557046).

Methods: Two paired anterior nasal swabs or two paired nasopharyngeal swabs were collected from each participant. Swabs were tested by the LumiraDx SARS-CoV-2 antigen test and compared with real-time polymerase chain reaction (rt-PCR; Roche cobas 6800 platform).

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Objective: Curettage adenoidectomy is one of the most common methods of adenoidectomy. This study reports the incidence of residual adenoid tissue after curettage and grades the degree of post-nasal space obstruction using fibre-optic nasopharyngoscopy.

Methods: A retrospective study of 425 consecutive patients undergoing curette adenoidectomy in a 5-year period.

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Background: Malignant phyllodes tumor is a rare and potentially aggressive breast neoplasm. Little information is available regarding the optimal management of these lesions and rarer still are data regarding survival. The current study used a large population database to determine prognostic factors that predict cause-specific survival (CSS).

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Objective: Benign prostatic hyperplasia (BPH) is one of the most common conditions associated with ageing in men. BPH often presents as lower urinary tract symptoms (LUTS) due to difficulties in voiding and irritability of the bladder. We conducted a retrospective cohort study within the Integrated Primary Care Information (IPCI) database, a general practitioners database in The Netherlands, to assess the incidence of LUTS suggestive of BPH (LUTS/BPH) in the general population.

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Hops and hop extracts are approved and widely used bittering agents in the brewing of beer. During recent years, preisomerized alpha hop acids and reduced preisomerized alpha hop acids have been introduced as effective and economical bittering agents that may be added late in the brewing process. Although hops have been used for centuries, there are few studies in the literature on the safety of this ingredient.

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A study of the effects of sucrose acetate isobutyrate (SAIB) ingestion was conducted in 13 male and 14 female healthy human volunteers. SAIB, in a gum arabic/water emulsion diluted with orange juice, was ingested once daily, at a dose of 20 mg SAIB/kg body weight in a total volume of 1.16 ml/kg body weight, for a period of 2 wk following a 1-week control period.

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A three-generation reproduction study of sucrose acetate isobutyrate (SAIB) in Fischer 344 rats and teratology studies in Fischer 344 rats and New Zealand white rabbits were performed. Dietary SAIB concentrations to provide dose levels of 0, 0.5, 1.

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Sucrose acetate isobutyrate (SAIB) is used as an emulsion stabilizer in citrus-based soft drinks. A 4-week range-finding study and a 1-year chronic toxicity study were conducted to determine the tolerance and effects of this food additive in cynomolgus monkeys. SAIB was administered by gavage in corn oil solutions to groups of one monkey of each sex in the range-finding study and four monkeys of each sex in the 1-year study.

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Sucrose acetate isobutyrate (SAIB), a food additive used as a flavour emulsion stabilizer in citrus-based soft drinks, was evaluated for chronic toxicity in B6C3F1 mice and Fischer 344 rats. SAIB dissolved in acetone was blended into NIH07 rodent diet at concentrations that were adjusted weekly during the first 12 to 18 months of the studies so that ingested dose levels per kg body weight were constant. Groups of 20 rats per sex were given dose levels of 0.

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Preliminary short-term toxicity studies of sucrose acetate isobutyrate (SAIB) in the dog demonstrated that addition of this additive to the diet was associated with an increase in liver size and elevated serum alkaline phosphatase activity with no evidence of pathological change by light microscopy. To determine the basis for these changes, a 12-week oral toxicity study of SAIB was conducted in the dog and a similar study was performed in the rat. SAIB was fed in the diet to groups of six beagle dogs of each sex at 0, 0.

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Sucrose acetate isobutyrate (SAIB), a mixture of esters of sucrose with a composition approximating the name sucrose diacetate hexaisobutyrate, has been used for over 30 yr in many countries as a 'weighting' or 'density-adjusting' agent in non-alcoholic carbonated and non-carbonated beverages. As part of the demonstration of safety of SAIB as a direct food additive in human diets, a program of toxicity testing was started in the late 1950s that culminated in extensive studies of SAIB in rodents, monkeys and humans over the last decade. This review summarizes the toxicity data, accrued up until 1988, that precede the safety studies published elsewhere in this issue.

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Concentrated organic residues extracted from 5 blended aliquots of commercial beers were evaluated for their ability to induce sister chromatid exchange (SCE), chromosomal aberrations and forward mutation in Chinese hamster ovary (CHO) cells. Each extract was prepared by blending 4 commercial beers of similar ingredients and brewing method, passing the beer pool over XAD-2 resin, extracting the resin and concentrating the extract. Studies were performed both with and without metabolic activation using variable amounts of reconstituted residues from 225-fold concentrates of the blended samples.

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Dietary sodium saccharin is associated with bladder tumors when fed at high levels to the male rat. Under these conditions urinary pH, sodium concentration, and volume are elevated and proliferative changes are present in the urothelium. Extensive epidemiological studies have shown that saccharin does not increase the risk of bladder cancer in humans and laboratory investigations have shown that sodium saccharin is not mutagenic and does not bind to DNA.

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Caramel Colour IV prepared from [U-14C]glucose was ultrafiltered in order to isolate the high molecular weight colour fraction (HMCF). The colour fraction that was non-permeable to a 10,000-Da porosity membrane, contained 84% of the colour, 22% of the solids and 24% of the radioactivity of the [14C]Caramel Colour IV. The absorption, distribution and excretion of [14C]HMCF were evaluated in male rats after administration of single or multiple oral doses of the material at a dosage level of 2.

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Caramel Colour IV, a type of caramel colour used in the manufacture of cola soft drinks, was evaluated for subchronic and chronic toxicity in rats, and carcinogenicity in Fischer-344 (F344) rats and B6C3F1 mice. In each of the studies, Caramel Colour IV was mixed with demineralized water and the solutions given to the animals ad lib. in the drinking fluid.

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Caramel Colour III is used as a colour additive in beers and a variety of foods. Beer is the most important single source of Caramel Colour III in the diet although consumption of dark beers has been decreasing in recent years. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has established an acceptable daily intake of 200 mg/kg/day for Caramel Colour III.

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Caramel colours used in the manufacture of a wide variety of foods and beverages have been an item of commerce for more than one hundred years. The regulatory history of these additives in the US, the UK, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the EC is reviewed, and an introduction to the safety studies of caramel colours in this issue of Food and Chemical Toxicology is provided.

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Caramel Colour II is a distinct type of colourant with a pronounced reddish hue. It is made with sulphite reactants but without ammonia. The red colour and a high alcohol solubility provide functional characteristics that are important in foods or beverages containing natural flavour extractives.

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The antihypertensive and metabolic effects of placebo (PL), a fixed combination of hydrochlorothiazide (25 mg) and triamterene (50 mg) (HCTZ/TRI), atenolol (25 mg) (Atc-25), atenolol (50 mg) (Ate-50) and their combination with HCTZ/TRI given once daily, were tested on 256 patients with mild-to-moderate essential-hypertension. After 3 weeks of PL monotherapy, 43 patients were randomized to PL (group 1), 41 patients to HCTZ/TRI (group 2), 44 patients to Ate-25 (group 3), 42 patients to Ate-50 (group 4), 43 patients to Ate-25/HCTZ/TRI (group 5), and 43 patients to Ate-50/HCTZ/TRI (group 6) in a double-blind parallel design study and were followed for 4 weeks. At the end of week 7, those patients who were randomized to groups 5 and 6 were allowed to continue for an additional 12 weeks, if their arterial pressure was satisfactorily controlled.

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Sodium saccharin and sodium ascorbate are known to promote urinary bladder carcinogenesis in rats following initiation with N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) or N-butyl-N-(4-hydroxybutyl) nitrosamine. Sodium salts of other organic acids have also been shown to be bladder tumor promoters. In addition, these substances increase urothelial proliferation in short term assays in rats when fed at high doses.

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Naloxone binding to T lymphocytes seems to occur both at the outer cell surface and in the interior of the cell. The binding sites on the outer membrane appear from previous work to be of low affinity and to be displaced by morphine only at very high concentrations. Permeable cells seem to express both high and low affinity binding sites in their interiors.

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Three methods used to detect proliferative changes in the rat urothelium, light microscopy, scanning electron microscopy, and autoradiography, were compared for their sensitivity in detecting changes produced by administration of sodium saccharin. Weanling male F344 rats were fed sodium saccharin as 0, 3, 5, or 7.5% of the diet, and the bladders were evaluated after 4, 7, and 10 wks of feeding.

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5 concentrated extracts of commercial beers were prepared using XAD-2 resin. The residues were subjected to evaluation for mutagenic activity in Salmonella typhimurium strains TA98, TA100 and TA102. The tests were conducted using preincubation protocols including provisions for S9 metabolic activation.

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