A broader view on deriving a reference dose for THC traces in foods

An Acute Reference Dose (ARfD) of 1 µg of delta-9-tetrahydrocannabinol (THC) per kilogram (kg) of body weight (bw) per day was recommended by the European Food Safety Authority (EFSA) for its assessment of possible acute health risks from the intake of industrial hemp food products. The scientific basis for this opinion, such as their choice of a Point of Departure for identification of the Lowest Observed Adverse Effect Level (LOAEL) for THC on the central nervous system, and the seeming absence of an experimental No Observed Adverse Effect Level (NOAEL), is critically reviewed. Moreover, the risk assessment for an ARfD derivation for THC is then reconsidered. In contrast to the EFSA Scientific Opinion of 2015, a higher LOAEL is presently identified from pharmacokinetic and pharmacodynamic studies, and forensic data, in representative cohorts of healthy humans after oral administrations of low THC doses. A NOAEL for THC is derived through this combination of results, demonstrating a threshold for impairment of psychomotor function only after intake of an oral THC bolus beyond 2.5 mg for the average healthy adult. This 2.5 mg dose produces mean THC blood serum levels of <2 ng/mL, as well as do two doses when taken daily within a time interval of ≥6 h. The forensic threshold of THC that is correlated with the impairment of psychomotor function is known to be between 2 and 5 ng/mL in blood serum for adults. For an appropriately spaced intake of 2 x 2.5 mg THC per day, an adult can therefore be regarded as being at the NOAEL. Applying a default uncertainty factor of 10 for intraspecies variability to a NOAEL of 2 x 2.5 mg (over ≥6 hours) for THC, yields a “daily dose of no concern” or a “tolerable upper intake level” of 0.50 mg, corresponding to 7 µg/kg bw. Starting with a NOAEL of only 2.5 mg, consumed as a single bolus, the lowest possible daily ARfD of THC would therefore be 0.25 mg, or 3.5 µg/kg bw for healthy adults, as the absolutely most conservative estimate. Other justifiable estimates have ranged up to 14 µg/kg bw per day

The (ethylenedinitrilo)-tetraacetate titration of calcium and magnesium in ocean waters II. Determination of magnesium

M odifications of the EDTA titration of total hardness have been evaluated for use ,n determining magnesium in sea water. In this procedure EDTA is the titrant, Eriochrome Blue Black B the indicator, and ethanolamine the buffer. Various conditions necessary for accurate sea water titrations have been established. A mean magnesium-chlorinity ratio of 0.06689 was obtained when 30 sea water samples were titrated

The (ethylenedinitrilo) tetraacetate titration of calcium and magnesium in ocean waters

Various factors influencing the determination of calcium in ocean water by (ethylenedinitrilo)tetre.e.cetate titration have been investigated. Using Cal-Red as indicator, the method has been applied in titrating 36 ocean samples. A calcium-chlorinity ratio of 0.02134 was obtained. The speed, preciseness, accuracy and simplicity of the method should encourage its future use

Comparison of agar gel immunodiffusion test, enzyme-linked immunosorbent assay and PCR in diagnostics of enzootic bovine leukosis

Bovine leukaemia virus (BLV) is a retrovirus that induces a chronic infection in cattle. Once infected, cattle remain virus carriers for life and start to show an antibody response within a few weeks after infection. Eradication and control of the disease are based on early diagnostics and segregation of the carriers. The choice of a diagnostic method depends on the eradication programme, money resources and characteristics of the herd to be analysed. The agar gel immunodiffusion (AGID) test has been the serological test of choice for routine diagnosis of serum samples. Nevertheless, in more recent years, the enzyme-linked immunosorbent assay (ELISA) has replaced the AGID for large scale testing. For this purpose, commercially available BLV-ELISA kits were compared to the AGID and to the polymerase chain reaction (PCR) method performed with two sets of primers, amplifying env region. The ELISA kit based on the p24 core protein was found to be less specific and served as a screening test. The ELISA kit based on the envelope glycoprotein (gpSI) served as a verification test and gave a good correlation with the AGID test and PCR method. However, ELISA showed a higher sensitivity than AGID. The p24 based ELiSA was useful for screening a large number of samples, whereas gp51 based ELISA, AGID and PCR were more important for detecting the antibody response against the individual BLV-proteins and therefore for verification of the infection with BLV

Analysis of isomeric mixtures by molecular rotational resonance spectroscopy

Recent developments in molecular rotational resonance (MRR) spectroscopy that have enabled its use as an analytical technique for the precise determination of molecular structure are reviewed. In particular, its use in the differentiation of isomeric compounds—including regioisomers, stereoisomers and isotopic variants—is discussed. When a mixture of isomers, such as resulting from a chemical reaction, is analyzed, it is highly desired to be able to unambiguously identify the structures of each of the components present, as well as quantify them, without requiring complex sample preparation or reference standards. MRR offers unique capabilities for addressing this analytical challenge, owing to two factors: its high sensitivity to a molecule's structure and its high spectral resolution, allowing mixtures to be resolved without separation of components. This review introduces core theoretical principles, an introduction to MRR instrumentation and the methods by which spectra can be interpreted with the aid of computational chemistry to correlate the observed patterns to molecular structures. Recent articles are discussed in which this technique was applied to help chemists complete challenging isomer analyses. Developments in the use of MRR for chiral analysis and in the measurement of isotopically labeled compounds are also highlighted

Acoustic Properties of Soybeans

Acoustic transmission and impact force response methods were investigated for classification of soybeans. The transmission method was slow and not suitable for real-time application. A polynomial was fitted to the deconvolved frequency spectrum of acoustic impulse data for soybeans. The curve fitting procedure successfully predicted the mass of each soybean. The size of soybeans was related to the bandwidth. Diseased soybeans consistently showed narrower bandwidths than healthy soybeans. The diseased and damaged soybeans had broad variations in low frequency which was quantifiable by threshholding the error of fit in the curve fitting procedure

Profile of hospital Admissions of childhood poisoning at a North-central Nigerian tertiary health care centre

Background: Childhood poisoning is an important but preventable cause of morbidity and mortality in the paediatric subpopulation. There is the continuous need to describe the pattern of childhood poisoning and to create public awareness on the common agents of poison in this environment.Objectives: To determine the pattern of childhood poisoning and to bridge the existing knowledge gap on childhood poisoning in North-Central Nigeria.Patients and methods: A retrospective study of case records of children admitted and treated for childhood poisoning at the Emergency Paediatrics Unit of the Jos University Teaching Hospital, Jos over a five year period (February 2008-February 2013) was undertaken. The data extracted from the case records included bio-data, date of admission, type and route of poison exposure, level of education and occupation of parents of affected children, treatment received and outcomes.Results: Twenty-six (0.94%) out of a total of 2,770 children were admitted and treated for poisoning. Their ages ranged from 5 months to 13 years. Children aged 0 to 2 years accounted for 12 (46.2%) cases with a mean age of 1.88 years. There were 10 (38.5%) male and 16 (61.5%) female with a male: female ratio of 0.62:1. Organophosphate and kerosene accounted for 9 (34.6%) and 6 (23.1%) of all cases respectively. Twenty-four (92.3%) of the poisoning were accidental while 2(7.7%) were intentional. Oral route was the commonest route of poison exposure in 20 (76.9%) and 24 (92.3%) of all cases which occurred in their home environment. gastrointestinal system symptoms were the most frequent clinical presentation 16 (61.5%). Thirteen (50.0%) of the affected victims presented to the hospital in 1-6 hours of poison exposure. Indications for hospital admissions in decreasing order of frequency were dehydration 7 (26.9%), seizures 6 (23.1%) and coma 6 (23.1%). Six (23.1%) of patients received palm oil/milk as home remedies prior to hospital presentation. There was a mortality rate of 3.8% from carbon monoxide poisoning. Mean duration of hospital stay was 1.87 days.Conclusions: Organophosphate is the commonest cause of childhood poisoning in North-Central Nigeria and children aged 0-2 years are the most vulnerable age group for accidental poisoning while older children aged 13 years and above for intentional poisoning. Therefore, there are needs to increase and sustain public health awareness on childhood poisoning and the government to provide poisoning centres and improve standards of living.Keywords: Pattern, admissions, poisoning, children, North-Central NigeriaJos Journal of Medicine, Volume 7 No.

Regulation and dysregulation of immunoglobulin E: a molecular and clinical perspective

<p>Abstract</p> <p>Background</p> <p>Altered levels of Immunoglobulin E (IgE) represent a dysregulation of IgE synthesis and may be seen in a variety of immunological disorders. The object of this review is to summarize the historical and molecular aspects of IgE synthesis and the disorders associated with dysregulation of IgE production.</p> <p>Methods</p> <p>Articles published in Medline/PubMed were searched with the keyword Immunoglobulin E and specific terms such as class switch recombination, deficiency and/or specific disease conditions (atopy, neoplasia, renal disease, myeloma, etc.). The selected papers included reviews, case reports, retrospective reviews and molecular mechanisms. Studies involving both sexes and all ages were included in the analysis.</p> <p>Results</p> <p>Both very low and elevated levels of IgE may be seen in clinical practice. Major advancements have been made in our understanding of the molecular basis of IgE class switching including roles for T cells, cytokines and T regulatory (or Treg) cells in this process. Dysregulation of this process may result in either elevated IgE levels or IgE deficiency.</p> <p>Conclusion</p> <p>Evaluation of a patient with elevated IgE must involve a detailed differential diagnosis and consideration of various immunological and non-immunological disorders. The use of appropriate tests will allow the correct diagnosis to be made. This can often assist in the development of tailored treatments.</p

Regulation and Dysregulation of Immunoglobulin E: A Molecular and Clinical Perspective

Background: Altered levels of Immunoglobulin E (IgE) represent a dysregulation of IgE synthesis and may be seen in a variety of immunological disorders. The object of this review is to summarize the historical and molecular aspects of IgE synthesis and the disorders associated with dysregulation of IgE production.Methods: Articles published in Medline/PubMed were searched with the keyword Immunoglobulin E and specific terms such as class switch recombination, deficiency and/or specific disease conditions (atopy, neoplasia, renal disease, myeloma, etc.). The selected papers included reviews, case reports, retrospective reviews and molecular mechanisms. Studies involving both sexes and all ages were included in the analysis.Results: Both very low and elevated levels of IgE may be seen in clinical practice. Major advancements have been made in our understanding of the molecular basis of IgE class switching including roles for T cells, cytokines and T regulatory (or Treg) cells in this process. Dysregulation of this process may result in either elevated IgE levels or IgE deficiency.Conclusion: Evaluation of a patient with elevated IgE must involve a detailed differential diagnosis and consideration of various immunological and non-immunological disorders. The use of appropriate tests will allow the correct diagnosis to be made. This can often assist in the development of tailored treatments