Pharmacokinetics, pharmacodynamics, and safety of subcutaneous anifrolumab in patients with systemic lupus erythematosus, active skin disease, and high type I interferon gene signature: a multicentre, randomised, double-blind, placebo-controlled, phase 2 study.

BACKGROUND: 300 mg of intravenous anifrolumab every 4 weeks added to standard-of-care treatment for patients with systemic lupus erythematosus (SLE) reduced disease activity and glucocorticoid requirement in a previous phase 3 trial. Because patients might find subcutaneous administration more convenient than intravenous delivery, we aimed to evaluate the pharmacokinetics, pharmacodynamics, safety, and efficacy of subcutaneous anifrolumab in patients with SLE, active skin disease, and a high type I interferon gene signature. METHODS: This multicentre, randomised, double-blind, placebo-controlled, phase 2 study was done at 12 hospitals and outpatient clinics in Hungary, South Korea, Poland, and the USA. Eligible patients were aged 18-70 years, and had SLE with high type I interferon gene signature and an activity score on the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) of at least 10. Enrolled participants were randomly assigned (3:1:3:1) by use of a voice-web response system to receive either 150 mg of subcutaneous anifrolumab or corresponding placebo, or 300 mg of subcutaneous anifrolumab or corresponding placebo in addition to stable standard-of-care treatment. The study was double-blinded with respect to intervention but not dose, until 12 weeks. Doses of oral glucocorticoids were tapered after week 12. The primary pharmacokinetic endpoint was the serum concentration of anifrolumab based on the maximum concentration after the first dose and the minimum (trough) concentration before subsequent doses and was measured in all patients who received anifrolumab and had at least one quantifiable serum pharmacokinetics observation following the first dose. The primary pharmacodynamic endpoint was neutralisation of the type I interferon pharmacodynamic signature at week 12 and was assessed in all patients with a high type I interferon pharmacodynamics signature at baseline based on a 21-gene test. Safety was evaluated in the full analysis set, which included all patients who received at least one dose of anifrolumab. This trial is completed and is registered at ClinicalTrials.gov, NCT02962960. FINDINGS: Between March 14, 2017, and Oct 26, 2017, 36 patients were randomly assigned to receive 150 mg of anifrolumab (n=14), 300 mg of anifrolumab (n=13), or placebo (n=9). Two patients in the anifrolumab 150 mg group were excluded from the pharmacodynamic analysis set (n=34). Ten (71%) of 14 patients in the anifrolumab 150 mg group, ten (77%) of 13 patients in the anifrolumab 300 mg group, and nine (100%) of the nine patients in the placebo group completed 52 weeks of treatment. At week 12, pre-dose mean trough serum concentrations of anifrolumab were more than dose proportional between the anifrolumab 150 mg group (19·82 µg/mL [SD 15·01]) and the anifrolumab 300 mg group (60·28 µg/mL [43·66]), and the pharmacokinetics were non-linear. At week 12, the median percentage neutralisation of the type I interferon gene signature was higher with 150 mg (88·0% [median absolute deviation 7·4]) and 300 mg (90·7% [3·3]) of anifrolumab than with placebo (18·5% [8·1]), and more patients in the anifrolumab 150 mg group and the anifrolumab 300 mg group than in the placebo group had neutralisation of 75% or more (eight [67%] of 12 vs ten [77%] of 13 vs one [11%] of nine). At least one adverse event was reported by 23 (85%) of 27 patients in the anifrolumab groups and by seven (78%) of nine patients in the placebo group; most adverse events were of mild-to-moderate severity. Serious adverse events were reported in six (22%) of 27 patients in the anifrolumab groups (four patients in the 150 mg group and two in the 300 mg group). No serious adverse events were reported in the placebo group. Herpes zoster infection was reported by three (11%) of 27 patients in the anifrolumab groups and by one (11%) of nine patients in the placebo group. There were no treatment-related deaths. INTERPRETATION: Anifrolumab, administered subcutaneously every 2 weeks to patients with SLE and moderate-to-severe skin manifestations, had non-linear pharmacokinetics that were more than dose proportional, and neutralised the type I interferon gene signature in a dose-dependent manner. The safety profile was consistent with previous studies of intravenous anifrolumab, supporting the continued development of anifrolumab as a subcutaneously administered therapy for patients with SLE. FUNDING: AstraZeneca.

Simulating clinical trial visits yields patient insights into study design and recruitment.

PURPOSE: We elicited patient experiences from clinical trial simulations to aid in future trial development and to improve patient recruitment and retention. PATIENTS AND METHODS: Two simulations of draft Phase II and Phase III anifrolumab studies for systemic lupus erythematosus (SLE)/lupus nephritis (LN) were performed involving African-American patients from Grady Hospital, an indigent care hospital in Atlanta, GA, USA, and white patients from Altoona Arthritis and Osteoporosis Center in Altoona, PA, USA. The clinical trial simulation included an informed consent procedure, a mock screening visit, a mock dosing visit, and a debriefing period for patients and staff. Patients and staff were interviewed to obtain sentiments and perceptions related to the simulated visits. RESULTS: The Atlanta study involved 6 African-American patients (5 female) aged 27-60 years with moderate to severe SLE/LN. The Altoona study involved 12 white females aged 32-75 years with mild to moderate SLE/LN. Patient experiences had an impact on four patient-centric care domains: 1) information, communication, and education; 2) responsiveness to needs; 3) access to care; and 4) coordination of care; and continuity and transition. Patients in both studies desired background material, knowledgeable staff, family and friend support, personal results, comfortable settings, shorter wait times, and greater scheduling flexibility. Compared with the Altoona study patients, Atlanta study patients reported greater preferences for information from the Internet, need for strong community and online support, difficulties in discussing SLE, emphasis on transportation and child care help during the visits, and concerns related to financial matters; and they placed greater importance on time commitment, understanding of potential personal benefit, trust, and confidentiality of patient data as factors for participation. Using these results, we present recommendations to improve study procedures to increase retention, recruitment, and compliance for clinical trials. CONCLUSION: Insights from these two studies can be applied to the development and implementation of future clinical trials to improve patient recruitment, retention, compliance, and advocacy.

Geologic occurrences of erionite in the United States: an emerging national public health concern for respiratory disease.

Erionite, a mineral series within the zeolite group, is classified as a Group 1 known respiratory carcinogen. This designation resulted from extremely high incidences of mesothelioma discovered in three small villages from the Cappadocia region of Turkey, where the disease was linked to environmental exposures to fibrous forms of erionite. Natural deposits of erionite, including fibrous forms, have been identified in the past in the western United States. Until recently, these occurrences have generally been overlooked as a potential hazard. In the last several years, concerns have emerged regarding the potential for environmental and occupational exposures to erionite in the United States, such as erionite-bearing gravels in western North Dakota mined and used to surface unpaved roads. As a result, there has been much interest in identifying locations and geologic environments across the United States where erionite occurs naturally. A 1996 U.S. Geological Survey report describing erionite occurrences in the United States has been widely cited as a compilation of all US erionite deposits; however, this compilation only focused on one of several geologic environments in which erionite can form. Also, new occurrences of erionite have been identified in recent years. Using a detailed literature survey, this paper updates and expands the erionite occurrences database, provided in a supplemental file (US_erionite.xls). Epidemiology, public health, and natural hazard studies can incorporate this information on known erionite occurrences and their characteristics. By recognizing that only specific geologic settings and formations are hosts to erionite, this knowledge can be used in developing management plans designed to protect the public.

Preclinical pharmacology and pharmacokinetics of AZD3783, a selective 5-hydroxytryptamine 1B receptor antagonist.

The preclinical pharmacology and pharmacokinetic properties of (2R)-6-methoxy-8-(4-methylpiperazin-1-yl)-N-(4-morpholin-4-ylphenyl)chromane-2-carboxamide (AZD3783), a potent 5-hydroxytryptamine 1B (5-HT(1B)) receptor antagonist, were characterized as part of translational pharmacokinetic/pharmacodynamic hypothesis testing in human clinical trials. The affinity of AZD3783 to the 5-HT(1B) receptor was measured in vitro by using membrane preparations containing recombinant human or guinea pig 5-HT(1B) receptors and in native guinea pig brain tissue. In vivo antagonist potency of AZD3783 for the 5HT(1B) receptor was investigated by measuring the blockade of 5-HT(1B) agonist-induced guinea pig hypothermia. The anxiolytic-like potency was assessed using the suppression of separation-induced vocalization in guinea pig pups. The affinity of AZD3783 for human and guinea pig 5-HT(1B) receptor (K(i), 12.5 and 11.1 nM, respectively) was similar to unbound plasma EC(50) values for guinea pig receptor occupancy (11 nM) and reduction of agonist-induced hypothermia (18 nM) in guinea pig. Active doses of AZD3783 in the hypothermia assay were similar to doses that reduced separation-induced vocalization in guinea pig pups. AZD3783 demonstrated favorable pharmacokinetic properties. The predicted pharmacokinetic parameters (total plasma clearance, 6.5 ml/min/kg; steady-state volume of distribution, 6.4 l/kg) were within 2-fold of the values observed in healthy male volunteers after a single 20-mg oral dose. This investigation presents a direct link between AZD3783 in vitro affinity and in vivo receptor occupancy to preclinical disease model efficacy. Together with predicted human pharmacokinetic properties, we have provided a model for the quantitative translational pharmacology of AZD3783 that increases confidence in the optimal human receptor occupancy required for antidepressant and anxiolytic effects in patients.

Development of a PET radioligand for the central 5-HT1B receptor: radiosynthesis and characterization in cynomolgus monkeys of eight radiolabeled compounds.

INTRODUCTION: The serotonin 1B (5-HT(1B)) receptor has been implicated in several psychiatric disorders and is a potential pharmacological target in the treatment of depression. The aim of this study was to develop a radioligand for positron emission tomography (PET) imaging of the 5-HT(1B) receptor in the primate brain in vivo. METHODS: Eight carboxamide radioligands (1-8) from three different core structures were radiolabeled with carbon-11 employing N-methylation with [(11)C]methyl triflate on the piperazine structural moiety. In vivo PET evaluation of each radioligand was performed in cynomolgus monkeys and included analysis of radioactive metabolites measured in plasma using high-performance liquid chromatography. RESULTS: In a total of 12 radiosynthesis of the eight radioligands, the mean decay corrected yield was 11%, and the mean specific radioactivity was 299 GBq/µmol (8075 Ci/mmol) at time of administration. Of the eight tested candidates, [(11)C]6 demonstrated the most promising in vivo characteristics, showing high binding in 5-HT(1B) receptor-rich regions and low binding in the cerebellum. When inspecting data from all eight compounds, lipophilicity appeared as a physicochemical property that could be related to favorable in vivo imaging characteristics. CONCLUSION: Candidate [(11)C]6, i.e., [(11)C]AZ10419369, exhibited high binding potentials in regions known to contain 5-HT(1B) receptors and was nominated for further preclinical characterization and PET examination in human subjects.

Dose-dependent binding of AZD3783 to brain 5-HT1B receptors in non-human primates and human subjects: a positron emission tomography study with [11C]AZ10419369.

RATIONALE: The serotonin 5-HT(1B) receptor is a potential target for the pharmacologic treatment of depression. Positron emission tomography (PET) determination of 5-HT(1B) receptor occupancy with drug candidates targeting this receptor in non-human primate and human subjects may facilitate translation of research from animal models and guide dose selection for clinical studies. AZD3783 is a recently developed, orally bioavailable 5-HT(1B) receptor antagonist with potential antidepressant properties. OBJECTIVES: To determine the relationship between plasma concentration of AZD3783 and occupancy at primate brain 5-HT(1B) receptors using PET and the radioligand [(11)C]AZ10419369. METHODS: PET studies with [(11)C]AZ10419369 were performed in three non-human primates at baseline and after intravenous injection of AZD3783. Subsequently, PET measurements were undertaken in six human subjects at baseline and after administration of different single oral doses of AZD3783 (1-40 mg). RESULTS: After administration in non-human primates and human subjects, AZD3783 reduced regional [(11)C]AZ10419369 binding in a dose-dependent and saturable manner. The AZD3783 plasma concentration required for 50% receptor occupancy (K (i,plasma)) for monkeys was 25 and 27 nmol/L in occipital cortex and striatum, respectively. Corresponding estimates for human occipital cortex and ventral striatum were 24 and 18 nmol/L, respectively. CONCLUSIONS: The potential antidepressant AZD3783 binds in a saturable manner to brain 5-HT(1B) receptors with a similar in vivo affinity for human and monkey receptors. [(11)C]AZ10419369 can be successfully used to determine occupancy at brain 5-HT(1B) receptors in vivo and constitutes a useful tool for dose selection in clinical studies with 5-HT(1B) receptor compounds.

Quantitative analysis of [11C]AZ10419369 binding to 5-HT1B receptors in human brain.

A novel radioligand for positron emission tomography (PET) imaging of serotonin 5-HT(1B) receptors, [(11)C]AZ10419369, has been recently described. In this study, the potential for quantitative analysis of [(11)C]AZ10419369 binding to central 5-HT(1B) receptors was evaluated in human subjects. PET measurements were performed after injection of [(11)C]AZ10419369 in 10 subjects. Data were analyzed with kinetic modeling and linear graphical analysis using the arterial plasma as input function, and with reference tissue models using cerebellar cortex as the reference region. Binding of [(11)C]AZ10419369 was highest in pallidum, ventral striatum, and occipital cortex and lowest in cerebellum. The percentage of unchanged radioligand in plasma was 97% to 99%, indicating that no significant amounts of radioactive metabolites were formed during the time of analysis. Time-activity curves of [(11)C]AZ10419369 could be described with both one-tissue compartment (1-TC) and two-tissue compartment (2-TC) models in the majority of subjects. The 2-TC model failed to deliver reasonable estimates of the kinetic parameters. However, stable estimates of binding potential (BP(ND)) were obtained by constraining K(1)/k(2) to the distribution volume obtained with the 1-TC model in the cerebellar cortex. BP(ND) values estimated with reference tissue models were correlated with the corresponding values obtained with kinetic modeling. The findings support the use of reference tissue models in applied clinical studies with [(11)C]AZ10419369.

Calculation and application of activity discriminants in lead optimization.

We present a technique for computing activity discriminants of in vitro (pharmacological, DMPK, and safety) assays and the application to the prediction of in vitro activities of proposed synthetic targets during the lead optimization phase of drug discovery projects. This technique emulates how medicinal chemists perform SAR analysis and activity prediction. The activity discriminants that are functions of 6 commonly used medicinal chemistry descriptors can be interpreted easily by medicinal chemists. Further, visualization with Spotfire allows medicinal chemists to analyze how the query molecule is related to compounds tested previously, and to evaluate easily the relevance of the activity discriminants to the activities of the query molecule. Validation with all compounds synthesized and tested in AstraZeneca Wilmington since 2006 demonstrates that this approach is useful for prioritizing new synthetic targets for synthesis.

Fenfluramine-induced serotonin release decreases [11C]AZ10419369 binding to 5-HT1B-receptors in the primate brain.

The need for positron emission tomography (PET)-radioligands that are sensitive to changes in endogenous serotonin (5-HT) levels in brain is recognized in experimental and clinical psychiatric research. We recently developed the novel PET radioligand [(11)C]AZ10419369 that is highly selective for the 5-HT(1B) receptor. In this PET-study in three cynomolgus monkeys, we examined the sensitivity of [(11)C]AZ10419369 to altered endogenous 5-HT levels. Fenfluramine-induced 5-HT release decreased radioligand binding in a dose-dependent fashion with a regional average of 27% after 1 mg/kg and 50% after 5 mg/kg. This preliminary study supports that [(11)C]AZ10419369 is sensitive to endogenous 5-HT levels in vivo and may serve as a tool to examine the pathophysiology and treatment of major psychiatric disorders.

De novo design of a picomolar nonbasic 5-HT(1B) receptor antagonist.

We describe herein the discovery of novel, de novo designed, 5-HT(1B) receptor antagonists that lack a basic moiety and that provide improved hERG and in vitro phospholipidosis profiles. We used a known 5-HT(1B) antagonist template as our starting point and focused on replacing the piperazine moiety. Pyrazole-based ideas were designed and synthesized among a small library of piperazine replacements. To our knowledge, these are the first potent, nonbasic, functionally active antagonists of the 5-HT(1B) receptor.

[N-methyl-3H3]AZ10419369 binding to the 5-HT1B receptor: in vitro characterization and in vivo receptor occupancy.

Radiotracers suitable for positron emission tomography studies often serve as preclinical tools for in vivo receptor occupancy. The serotonin 1B receptor (5-HT(1B)) subtype is a pharmacological target used to discover treatments for various psychiatric and neurological disorders. In psychiatry, 5-HT(1B) antagonists may provide novel therapeutics for depression and anxiety. We report on the in vitro and in vivo evaluation of tritiated 5-methyl-8-(4-methyl-piperazin-1-yl)-4-oxo-4H-chromene-2-carboxylicacid (4-morpholin-4-yl-phenyl)-amide ([N-methyl-(3)H(3)]AZ10419369), a potent 5-HT(1B) radiotracer. [N-methyl-(3)H(3)]-AZ10419369 showed saturable single-site high-affinity in vitro binding (guinea pig, K(d) = 0.38 and human, K(d) = 0.37) to guinea pig or human 5-HT(1B) receptors in recombinant membranes and high-affinity (K(d) = 1.9 nM) saturable (B(max) = 0.099 pmol/mg protein) binding in membranes from guinea pig striatum. When [N-methyl-(3)H(3)]AZ10419369 was administered to guinea pigs by intravenous bolus, the measured radioactivity was up to 5-fold higher in brain areas containing the 5-HT(1B) receptor (striatum/globus pallidus, midbrain, hypothalamus, and frontal cortex) compared with the cerebellum, the nonspecific binding region. Specific uptake peaked 30 min after injection with slow dissociation from target regions, as suggested by the in vitro binding kinetic profile. Pretreatment with 6-fluoro-8-(4-methyl-piperazin-1-yl)-4-oxo-4H-chromene-2-carboxylic acid [4-(4-propionyl-piperazin-1-yl)-phenyl]-amide (AZD1134) and 2-aminotetralin (AR-A000002), 5-HT(1B)-selective ligands, inhibited [N-methyl-(3)H(3)]AZ10419369-specific binding in a dose-dependent manner. In the guinea pig striatum, AZD1134 (ED(50) = 0.017 mg/kg) occupies a greater percentage of the 5-HT(1B) receptors at a lower administered dose than AR-A000002 (ED(50) = 2.5 mg/kg). In vivo receptor occupancy is an essential component to build binding-efficacy-exposure relationships and compare novel compound pharmacology. [N-methyl-(3)H(3)]AZ10419369 is a useful preclinical tool for investigating 5-HT(1B) receptor occupancy for novel compounds targeting this receptor.

[11C]AZ10419369: a selective 5-HT1B receptor radioligand suitable for positron emission tomography (PET). Characterization in the primate brain.

The 5-HT1B receptor has been implicated in several psychiatric disorders and is a potential pharmacological target in the treatment of depression. Here we report the synthesis of a novel PET radioligand, [11C]AZ10419369 (5-methyl-8-(4-methyl-piperazin-1-yl)-4-oxo-4H-chromene-2-carboxylic acid (4-morpholin-4-yl-phenyl)-amide), for in vivo visualization of 5-HT1B receptors in the brains of macaques and humans subjects. [11C]AZ10419369 was prepared by N-methylation of (8-(1-piperazinyl)-5-methylchrom-2-en-4-one-2-(4-morpholinophenyl) carboxamide, using carbon-11 methyl triflate. Regional brain uptake patterns of [11C]AZ10419369 were characterized by PET measurements in two macaques and a preliminary study in two human subjects. In addition, AZ10419369 was prepared in tritium labeled form for in vitro autoradiography studies in macaque brain tissue sections. The radiochemical purity of [11C]AZ10419369 was >99% and specific radioactivity was >3600 Ci/mmol. After iv injection of [11C]AZ10419369, 3-4% was in brain after 7.5 min. The regional brain distribution of radioactivity was similar in humans and macaques showing the highest uptake of radioactivity in the occipital cortex and the basal ganglia, in accord with autoradiographic studies performed using [3H]AZ10419369. Uptake was moderate in the temporal and frontal cortical regions, lower in the thalamus and lowest in the cerebellum. In macaques pre-treated with the selective 5-HT1B receptor antagonist, AR-A000002, binding was reduced in a dose-dependent manner, consistent with specific binding to 5-HT1B receptors. These data support [11C]AZ10419369 as a suitable radioligand for labeling 5-HT1B receptors in the primate brain. This radioligand may be useful in future studies evaluating drug-induced receptor occupancy and measurement of brain 5-HT1B receptor levels in patients with psychiatric disorders.

Effects of ultraviolet irradiation on chemical and sensory properties of goat milk.

Sensory and chemical consequences of treating goat milk using an UV fluid processor were assessed. Milk was exposed to UV for a cumulative exposure time of 18 s and targeted UV dose of 15.8 +/- 1.6 mJ/cm2. A triangle test revealed differences between the odor of raw milk and UV irradiated milk. Oxidation and hydrolytic rancidity was measured by thiobarbituric acid reactive substances and acid degree values (ADV). As UV dose increased, there was an increase in thiobarbituric acid reactive substance values and ADV of the milk samples. A separate set of samples were processed using the fluid processor but with no UV exposure to see if lipase activity and agitation from pumping contributed to the differences in odor. The ADV increased at the same rate as samples exposed to UV; however, sensory studies indicated that the increase of free fatty acids was not enough to cause detectable differences in the odor of milk. Solid phase microextraction and gas chromatography were utilized for the analysis of volatile compounds as a result of UV exposure. There was an increase in the concentration of pentanal, hexanal, and heptanal (relative to raw goat milk) after as little as 1.3 mJ/cm2 UV dose. Ultraviolet irradiation at the wavelength 254 nm produced changes in the sensory and chemical properties of fluid goat milk.

Efficacy of UV light for the reduction of Listeria monocytogenes in goat's milk.

Certain types of goat's cheeses are produced using unpasteurized milk, which increases the food safety concerns for these types of products. Popularity and consumption of goat's milk products have increased, and the niche market includes gourmet goat's cheeses. The U.S. Code of Federal Regulations and the Pasteurized Milk Ordinance both address the possibility for processing alternatives to heat treatment, and the use of UV light treatment may be a viable alternative that still ensures the safety of the product. Fresh goat's milk was inoculated with Listeria monocytogenes (L-2289) at 10(7) CFU/ml and exposed to UV light using the CiderSure 3500 apparatus (FPE Inc., Macedon, NY). Inoculated milk was exposed to a UV dose range between 0 and 20 mJ/cm2 to determine the optimal UV dose. A greater than 5-log reduction was achieved (P < 0.0001) when the milk received a cumulative UV dose of 15.8 +/- 1.6 mJ/cm2. The results of this study indicate that UV irradiation could be used for the reduction of L. monocytogenes in goat's milk.

Effect of hydrogen peroxide and other protease inhibitors on Cryptosporidium parvum excystation and in vitro development.

This study was undertaken to observe the effects of hydrogen peroxide on Cryptosporidium parvum oocysts with respect to protease activity in comparison to known protease inhibitors. In assessing the possible mechanisms of action of hydrogen peroxide, treatment effectiveness was analyzed using 3 assays and the potential roles of proteases and cations were considered. Treatment of C. parvum oocysts with hydrogen peroxide inhibited protease activity up to 50% compared with untreated controls. Treatment of oocysts with chemicals that affect sulfhydryls, including N-ethylmaleimide and dithiolthreitol, inhibited protease activity by >90%. Treatment of oocysts with these chemicals, along with the protease inhibitors, phenylmethylsulfonyl fluoride (PMSF), ethylenediamine-tetraacetic acid, and cystatin, inhibited protease activity as well as in vitro excystation and infection in a cell culture assay. Several mechanisms may result in the successful inhibition of infection and excystation by hydrogen peroxide treatment, including: oxidation of oocyst wall proteins or lipids, chelating of cations necessary for infection, or hydroxyl radical-induced DNA damage to sporozoites, or both.

Penetration of surface-inoculated bacteria as a result of hydrodynamic shock wave treatment of beef steaks.

The top surface of the raw eye of round steaks was inoculated with either green fluorescent protein (GFP)-labeled Escherichia coli (E. coli-GFP) or rifampin-resistant E. coli (E. coli-rif). Cryostat sampling in concert with laser scanning confocal microscopy (LSCM) or plating onto antibiotic selective agar was used to determine if hydrodynamic shock wave (HSW) treatment resulted in the movement of the inoculated bacteria from the outer inoculated surface to the interior of intact beef steaks. HSW treatment induced the movement of both marker bacteria into the steaks to a maximum depth of 300 microm (0.3 mm). Because popular steak-cooking techniques involve the application of heat from the exterior surface of the steak to achieve internal temperatures ranging from 55 to 82 degrees C, the extent of bacterial penetration observed in HSW-treated steaks does not appear to pose a safety hazard to consumers.

Levels of Vibrio vulnificus and organoleptic quality of raw shellstock oysters (Crassostrea virginica) maintained at different storage temperatures.

Temperature abuse during raw oyster harvesting and storage may allow for the multiplication of natural spoilage flora as well as microbial pathogens, thus posing a potential health threat to susceptible consumers and compromising product quality. The objective of this study was to provide a scientific basis for determining whether different refrigeration and abuse temperatures for raw oysters would result in a spoiled product before it became unsafe. Raw shellstock oysters (Crassostrea virginica) purchased from a commercial Virginia processor were subjected to different temperature abuse conditions (7, 13, and 21 degrees C) over a 10-day storage period. Salinity, pH, halophilic plate count (HPC), total culturable Vibrio counts, and culturable Vibrio vulnificus counts were determined at each abuse condition. V. vulnificus isolates were confirmed by a specific enzyme-linked immunosorbent assay. Olfactory analysis was performed to determine consumer acceptability of the oysters at each abuse stage. The pH of the oysters decreased over time in each storage condition. The HPC increased 2 to 4 logs for all storage conditions, while olfactory acceptance decreased over time. V. vulnificus levels increased over time, reaching 10(5) to 10(6) CFU/g by day 6. The length of storage had a greater effect on the bacterial counts and olfactory acceptance of the oysters (P < 0.05) over time than did the storage temperature (P < 0.05).

[Fluoride and children]. / Le fluor et l'enfant.

Fluoride is considered as an essential carioprophylactic agent. However, its use raises problems related to the possible negative effects of excessive intake. Precautions are therefore necessary when prescribing fluoride to children. This includes: 1) evaluation of all sources of fluoride for each individual child and his/her family; 2) evaluation of the cariogenic risk for the child according to his/her environment; and 3) estimation of the family's ability to follow medical advice and prescriptions. The role of the practitioner is thus to adapt the fluoride prescription according to the age and particular cariogenic susceptibility of each child. Pediatricians, general practitioners and dentists need to be convinced of how important regular visits to the dentist are for all children, from an early age. Not only fluoride, but also nutrition and hygiene are essential factors in achieving good dental health in childhood.

Microbiological quality and safety of quahog clams, Mercenaria mercenaria, during refrigeration and at elevated storage temperatures.

The effects of storage temperatures and times on the microbiological quality and safety of hard-shelled quahog clams (Mercenaria mercenaria) were examined. Samples were stored at four different incubation temperatures (3.3, 7.2, 10.0, and 12.8 degrees C) for a period of 3 weeks, following their harvest from summer growing waters (> or = 27 degrees C) and winter waters (< or = 4 degrees C). Clams were analyzed for two naturally occurring pathogens, Vibrio parahaemolyticus and Vibrio vulnificus. During the summer, V. parahaemolyticus was isolated from 56% of the stored samples, with the highest concentration, 6,100/g, occurring on day 12 at 12.8 degrees C. Also, during the summer, V. vulnificus was isolated from 11% of the stored samples, with the highest concentration of 1,500/g occurring on day 15 at 7.2 degrees C. No Vibrio spp. were detected during the winter. During summer storage, aerobic mesophilic counts on plate count agar (PCA) containing 2% NaCl ranged from 10(4) to 10(8) CFU/g, and during storage of the winter samples, aerobic mesophilic PCA (with added NaCl) counts ranged from <100 to 10(4) CFU/g. Comparatively, summer storage mesophilic counts on PCA containing no added NaCl ranged from <100 to 10(5) CFU/g, and for the winter samples the range was <100 to 10(2) CFU/g. Coliform and fecal coliform counts ranged from <0.3 to 61.1/g and <0.3 to 24.4/g, respectively. There was no statistical correlation between the length of storage or the temperature of incubation and the presence of V. parahaemolyticus, V. vulnificus, coliforms, or fecal coliforms. However, storage time and incubation temperature affected the PCA counts (P < or = 0.05) in quahog clams.

Growth and histamine formation of Morganella morganii in determining the safety and quality of inoculated and uninoculated bluefish (Pomatomus saltatrix).

The objective of this study was to determine the effect of normal microflora and Morganella morganii on histamine formation and olfactory acceptability in raw bluefish under controlled storage conditions. Fillets inoculated with and without M. morganii were stored at 5, 10, and 15 degrees C for 7 days. Microbial isolates from surface swabs were identified and screened for histidine decarboxylase activity. Olfactory acceptance was performed by an informal sensory panel. Histamine levels were quantified using high-performance liquid chromatography and fluorescence detection. While olfactory acceptance decreased, histamine concentration and bacterial counts increased. Storage temperature had a significant effect on histamine levels, bacterial counts, and olfactory acceptance of the bluefish. Inoculation with M. morganii had a positive significant effect on histamine formation for bluefish held at 10 and 15 degrees C (P < 0.0001). The results of the study will serve in supporting U.S. Food and Drug Administration (FDA) regulations regarding guidance and hazard levels of histamine in fresh bluefish.