Methylmercury induced alterations in the nerve growth factor level in the developing brain.

Pre- and early postnatal stages in the development of the central nervous system (CNS) are very sensitive to the toxic effects of methylmercury. The influence of methylmercury on the level of nerve growth factor (NGF) during the development of CNS was studied. Sprague-Dawley rats were exposed indirectly throughout the fetal and suckling periods until weaning on postnatal day 25 (P 25) via their dams given methylmercury in the diet (3.9 mg/kg diet). In addition, after weaning offsprings were exposed directly to methylmercury via the diet until postnatal day 50 (P 50). The level of NGF was analyzed in cortical areas and in the septum with a sensitive enzyme immunoassay. The pups exposed to MeHg exhibited a 50% elevation in the level of NGF in the hippocampus on P 25 and P 50 compared to control animals. Concomitantly, the level of NGF decreased by 30% in the septum on P 25 and P 50, suggesting that the retrograde transport of NGF from hippocampus to septum could be affected by the exposure of methylmercury. The exact mechanism by which the low level of mercury is affecting the NGF concentration in the developing brain is yet unknown. The increase of NGF in the hippocampus and the decrease of NGF measured in the septum could reflect altered conditions for neurotrophic support in these areas of the brain as a result of the exposure to heavy metal. Thus, this finding might indicate a connection between exposure of heavy metals and neurodegeneration, such as that found in the basal forebrain in Alzheimer's disease.     

Differential expression of nm23 H-1 protein in conjunctival melanoma and potential precursor lesions

Loss of nm23 gene expression is believed to enhance metastatic spread in diverse human tumors, including skin melanoma. The purpose of this work was to determine the pattern and prognostic relevance of nm23 protein immunoexpression in conjunctival melanoma and potential precursor lesion. Formaldehyde-fixed, paraffin-embedded conjunctival specimens comprising 85 melanocytic lesions (nevi, primary aquired melanosis with and without atypia and primary and locally recurrent malignant melanomas) from 73 patients were used. Sections from all specimens were examined by light microscopy to assess diverse prognostic parameters. Additional sections were then immunostained for nm23 H-1 protein and the immunoreactivity was assessed semi-quantitatively. Survival data for all patients were retrieved from the National Causes of Death Registry of Sweden.Nm23 H-1 protein was differentially expressed in conjunctival melanocytic lesions, however loss of immunoexpression was not more common in melanocytic lesions asociated with a high risk of malignant transformation. Also, primary and recurrent conjunctival melanomas showed an essentially similar nm23 expression pattern and we could not associate the pattern of nm23 immunoexpression with an increased risk for malignant transformation or locally recurrent disease. While there was a tentative separation between cause-specific survival curves after excision for low and high nm23 expression conjunctival melanoma, there was no statistically significant association with metastatic death of patients. However, loss of nm23 protein immunoexpression may still be of some importance as a marker for prognosis in conjunctival melanoma because the present study could only detect large differences in survival. Our results suggest that any potential prognostic value of nm23 immunoexpression would be independent of other markers, underlining the importance of further studies.     

Analysis of the US Safety Data for Edaravone (Radicava®) From the Third Year After Launch

BackgroundAmyotrophic lateral sclerosis (ALS) is a progressive and fatal neuromuscular disease with no curative therapies. Edaravone (Radicava^®) (Mitsubishi Tanabe Pharma Corporation, Tokyo, Japan), approved in the United States (US) for ALS in adults in 2017, was shown in a clinical trial to slow the rate of physical functional decline in ALS and is administered intravenously. The aim of this paper is to summarize the observed safety profile from real-world patient use during the first 3 years of edaravone availability in the US.MethodsEdaravone usage data were collected, and adverse events (AEs) were identified from a postmarketing safety database from August 8, 2017 through August 7, 2020 (cutoff date).ResultsAs of October 3, 2020, 5207 ALS patients had been treated with edaravone. As of August 7, 2020, the most commonly reported AEs included death (not specified), drug ineffective, disease progression, therapeutic response unexpected, fall, asthenia, fatigue, muscular weakness, gait disturbance, and dyspnea. The most commonly reported serious AEs (SAEs) included death (not specified), pneumonia, disease progression, ALS, fall, dyspnea, respiratory failure, device-related infection, hospitalization, and injection-site infection. There were 687 deaths, with 494 reported as death without specifying the cause. Deaths were most commonly attributed to ALS, disease progression, respiratory failure, or pneumonia. Review for administration-site reactions revealed 95 AEs, including 34 site infections, with 22 SAEs (all non-fatal). Five non-fatal SAEs of anaphylaxis were reported.ConclusionIn the postmarketing reporting to date, no new safety signals were identified beyond those already known from the edaravone clinical trial program.     

Meeting report: International workshop on endocrine disruptors: Exposure and potential impact on consumers health

The French Agency for Food, Environmental and Occupational Health and Safety (Anses) hosted a two-day workshop on Endocrine Disruptors: Exposure and Potential Impact on Consumers Health, bringing together participants from international organizations, academia, research institutes and from German, Swedish, Danish and French governmental agencies. The main objective of the workshop was to share knowledge and experiences on endocrine disruptors (ED) exposure and potential impact on consumers’ health, to identify current risk assessment practices and knowledge gaps and issue recommendations on research needs and future collaboration. The following topics were reviewed: (1) Definition of ED, (2) endpoints to be considered for Risk assessment (RA) of ED, (3) non-monotonic dose response curves, (4) studies to be considered for RA (regulatory versus academic studies), (5) point of departure and uncertainty factors, (6) exposure assessment, (7) regulatory issues related to ED. The opinions expressed during this workshop reflect day-to-day experiences from scientists, regulators, researchers, and others from many different countries in the fields of risk assessment, and were regarded by the attendees as an important basis for further discussions. Accordingly, the participants underlined the need for more exchange in the future to share experiences and improve the methodology related to risk assessment for endocrine disrupters.     

Is small bowel biopsy necessary in adults with suspected celiac disease and IgA anti-endomysium antibodies?

The comparative diagnostic value of IgA anti-endomysium and IgA antigliadin antibodies in adults with histologically confirmed celiac disease is reported. Sera from 144 adult patients (without concurrent dermatitis herpetiformis or IgA deficiency) who underwent small bowel biopsy were analyzed for both IgA anti-endomysium and IgA anti-gliadin antibodies. Nineteen patients (13%) had celiac disease. The presence of IgA antiendomysium antibodies had a sensitivity of 74% and a specificity of 100%. The positive and negative predictive values were 100% and 96%, respectively, and the diagnostic accuracy was 97%. In contrast, IgA anti-gliadin antibodies had positive and negative predictive values of 28% and 96%, respectively, with a diagnostic accuracy of 71%. Based on these data, we suggest that small bowel biopsy is not necessary to diagnose celiac disease in symptomatic adults with IgA antiendomysium antibodies. Due to a negative predictive value of 96%, some symptomatic adults lacking anti-endomysium antibodies will not be correctly diagnosed without small bowel biopsy.     

Chemical determination of the m1 Moloney sarcoma virus pP60gag gene order: evidence for unique peptides in the carboxy terminus of the polyprotein.

The gene order of the ml Moloney sarcoma virus (mlMSV) specific pP60gag (P60) was determined by direct chemical analysis of the polyprotein. P60 was cleaved with cyanogen bromide (CNBr) into eight partial and complete fragments ranging in mass from 10,000 daltons to 58,000 daltons. Peptide maps of these fragments were compared to maps of p15, p12, and three CNBr fragments of p30. The polarity of p15 and p12 in a CNBr fragment of P60 was determined by carboxypeptidase A digestion; likewise the CNBr fragments of p30 were ordered by aminopeptidase digestion. The linear arrangement of P60 CNBr fragments gave the gene order of NH2-p15-p12-p30-COOH. The m3 isolate of MSV expresses a P70 gag polyprotein. Peptide maps of 48,000-dalton CNBr fragments of m3 P70 and ml P60 were similar and suggested that both polyproteins were similar through the NH2-terminal two-thirds of p30. However, the presence of peptides unique to the 10,500-dalton COOH-terminal fragment of m1MSV p30 and not present in the p30 of either m3MSV or Moloney leukemia virus suggested that the gag gene deletion in the m1 isolate begins in the p30 reading frame.     

Relationship between peroxisome proliferator‐activated receptor alpha activity and cellular concentration of 14 perfluoroalkyl substances in HepG2 cells

Peroxisome proliferator‐activated receptor alpha (PPARα) is a molecular target for perfluoroalkyl substances (PFASs). Little is known about the cellular uptake of PFASs and how it affects the PPARα activity. We investigated the relationship between PPARα activity and cellular concentration in HepG2 cells of 14 PFASs, including perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates and perfluorooctane sulfonamide (FOSA). Cellular concentrations were determined by high‐performance liquid chromatography–tandem mass spectrometry and PPARα activity was determined in transiently transfected cells by reporter gene assay. Cellular uptake of the PFASs was low (0.04–4.1%) with absolute cellular concentrations in the range 4–2500 ng mg^?1 protein. Cellular concentration of PFCAs increased with perfluorocarbon chain length up to perfluorododecanoate. PPARα activity of PFCAs increased with chain length up to perfluorooctanoate. The maximum induction of PPARα activity was similar for short‐chain (perfluorobutanoate and perfluoropentanoate) and long‐chain PFCAs (perfluorododecanoate and perfluorotetradecanoate) (approximately twofold). However, PPARα activities were induced at lower cellular concentrations for the short‐chain homologs compared to the long‐chain homologs. Perfluorohexanoate, perfluoroheptanoate, perfluorooctanoate, perfluorononanoate (PFNA) and perfluorodecanoate induced PPARα activities >2.5‐fold compared to controls. The concentration–response relationships were positive for all the tested compounds, except perfluorooctane sulfonate PFOS and FOSA, and were compound‐specific, as demonstrated by differences in the estimated slopes. The relationships were steeper for PFCAs with chain lengths up to and including PFNA than for the other studied PFASs. To our knowledge, this is the first report establishing relationships between PPARα activity and cellular concentration of a broad range of PFASs.     

Fruit and vegetable consumption and risk of cholecystectomy: a prospective cohort study of women and men

Purpose

Epidemiologic data on whether consumption of fruit and vegetables (FVs) decreases the risk of gallstone disease are sparse. Therefore, we examined the association between FV consumption and the 14-year risk of symptomatic gallstone disease (defined as occurrence of cholecystectomy) in a large group of middle-aged and elderly persons.

Methods

Data from two population-based cohorts were used, which included 74,554 men and women (born 1914–1952). Participants filled in a food frequency questionnaire in the late fall of 1997 and were followed up for cholecystectomy between 1998 and 2011 via linkage to the Swedish Patient Register. Cox regression models were used to obtain hazard ratios (HRs).

Results

During 939,715 person-years of follow-up, 2120 participants underwent a cholecystectomy (1120 women and 1000 men). An inverse association between FV consumption and risk of cholecystectomy was observed in age- and sex-adjusted analyses (P _trend = .036) but not in confounder-adjusted analyses (P _trend = .43). The multivariable-adjusted HR was 0.95 (95 % CI 0.83–1.08) for the highest compared with the lowest sex-specific quartile of FV consumption. There was no evidence of interactions with age (P = .25) or sex (P = .72) in analyses pooled by sex. However, an age-by-FV consumption interaction was observed in separate analyses of women (P = .010), with decreased HRs of cholecystectomy for ages up to 60 years.

Conclusions

This study supports an inverse association between FV consumption and risk cholecystectomy in women, although the association was restricted to women aged 48–60 years. In contrast, the study does not support an association in men.

     

Cloning of integrated Moloney sarcoma proviral DNA sequences in bacteriophage lambda.

We have identified integrated proviral DNA sequences of m1 and HT-1 isolates of Moloney sarcoma virus (MuSV) in EcoRI digests of transformed mink cell genomic DNA and have cloned these fragments in bacteriophage lambda. Both the lambda-HT1 phage recombinant, containing a 12.3-kilobase MuSV pair (kb) fragment, and the lambda-m1 phage recombinant, containing a 7.0-kb fragment, possess full copies of the sarcoma viruses along with 5' and 3' host flanking sequences. The MuSV proviral DNA sequences, 6.7 kb for HT-1 and 5.2 kb for m1, are colinear by heteroduplex microscopy with the 1.5-kb difference in size accounted for by two approximately equal to 0.8-kb deleted regions in m1. Both integrated viral genomes are terminally redundant and have integrated at the same site in the provirus but at different sites on the host chromosome. The host sequence flanking integrated HT-1 MuSV have been identified as a single EcoRI restriction fragment of 5.6 kb in normal mink cells.