Validated assays for the quantification of C9orf72 human pathology

A repeat expansion mutation in the C9orf72 gene is the leading known genetic cause of FTD and ALS. The C9orf72-ALS/FTD field has been plagued by a lack of reliable tools to monitor this genomic locus and its RNA and protein products. We have validated assays that quantify C9orf72 pathobiology at the DNA, RNA and protein levels using knock-out human iPSC lines as controls. Here we show that single-molecule sequencing can accurately measure the repeat expansion and faithfully report on changes to the C9orf72 locus in what has been a traditionally hard to sequence genomic region. This is of particular value to sizing and phasing the repeat expansion and determining changes to the gene locus after gene editing. We developed ddPCR assays to quantify two major C9orf72 transcript variants, which we validated by selective excision of their distinct transcriptional start sites. Using validated knock-out human iPSC lines, we validated 4 commercially available antibodies (of 9 tested) that were specific for C9orf72 protein quantification by Western blot, but none were specific for immunocytochemistry. We tested 15 combinations of antibodies against dipeptide repeat proteins (DPRs) across 66 concentrations using MSD immunoassay, and found two (against poly-GA and poly-GP) that yielded a 1.5-fold or greater signal increase in patient iPSC-motor neurons compared to knock-out control, and validated them in human postmortem and transgenic mouse brain tissue. Our validated DNA, RNA and protein assays are applicable to discovery research as well as clinical trials.

CHRNA5 gene variation affects the response of VTA dopaminergic neurons during chronic nicotine exposure and withdrawal

Nicotine is the principal psychoactive component in tobacco that drives addiction through its action on neuronal nicotinic acetylcholine receptors (nAChR). The nicotinic receptor gene CHRNA5, which encodes the α5 subunit, is associated with nicotine use and dependence. In humans, the CHRNA5 missense variant rs16969968 (G > A) is associated with increased risk for nicotine dependence and other smoking-related phenotypes. In rodents, α5-containing nAChRs in dopamine (DA) neurons within the ventral tegmental area (VTA) powerfully modulate nicotine reward and reinforcement. Although the neuroadaptations caused by long-term nicotine exposure are being actively delineated at both the synaptic and behavioral levels, the contribution of α5-containing nAChRs to the cellular adaptations associated with long-term nicotine exposure remain largely unknown. To gain insight into the mechanisms behind the influence of α5-containing nAChRs and the rs16969968 polymorphism on nicotine use and dependence, we used electrophysiological approaches to examine changes in nAChR function arising in VTA neurons during chronic nicotine exposure and multiple stages of nicotine withdrawal. Our results demonstrate that CHRNA5 mutation leads to profound changes in VTA nAChR function at baseline, during chronic nicotine exposure, and during short-term and prolonged withdrawal. Whereas nAChR function was suppressed in DA neurons from WT mice undergoing withdrawal relative to drug-naïve or nicotine-drinking mice, α5-null mice exhibited an increase in nAChR function during nicotine exposure that persisted throughout 5-10 weeks of withdrawal. Re-expressing the hypofunctional rs16969968 CHRNA5 variant in α5-null VTA DA neurons did not rescue the phenotype, with α5-SNP neurons displaying a similar increased response to ACh during nicotine exposure and early stages of withdrawal. These results demonstrate the importance of VTA α5-nAChRs in the response to nicotine and implicate them in the time course of withdrawal.

Sentinel lymph node biopsy for early oral cancer - accuracy and considerations in patient selection

Sentinel lymph node biopsy (SLNB) for staging oral squamous cell carcinoma (OSCC) patients presenting with early (T1 and T2 N0) disease in preference to elective neck dissection (END) remains controversial worldwide. A retrospective analysis of 145 patients who underwent sentinel lymph node biopsy for a previously untreated early oral cancer between 2010 and 2020 was performed. The primary outcome measures were predictors of occult metastases, accuracy of SLNB and disease specific plus overall survival. The negative predictive value, the false negative rate, and sensitivity for SLNB were 97%, 7.8%, and 92%, respectively. Depth of invasion (DOI) was a significant predictor of N status, overall survival, and disease specific survival. There was a significant difference in the incidence of the neck node metastasis in patients with DOI <5mm compared to those with DOI >5mm. For tumours >5mm there was a moderate to good correlation between radiological depth on contrast enhanced computed tomography (CECT) and histopathological DOI. Preoperative estimation of DOI may be a useful tool in the counselling of patients in the selection of either SLNB or END for N staging purposes in early OSCC.

MR1 encompasses at least six allele groups with coding region alterations

Unlike classical HLA class I genes, MR1 is assumed to have limited polymorphic positions. We developed a MR1 specific PCR assay and sequenced 56 DNA samples from cells with a diverse set of HLA genotypes. In this relatively small panel we found six allele groups encoding for different MR1 proteins. The two most frequent allele groups found in this panel had a frequency of 71% (MR1*01) and 25% (MR1*02), respectively. Moreover, the panel contained many intronic SNPs and silent variants, with individual samples containing up to 15 heterozygous positions. The data presented here is consistent with marked variation in MR1.

The medial habenula and interpeduncular nucleus circuitry is critical in addiction, anxiety, and mood regulation

Abstinence from chronic use of addictive drugs triggers an aversive withdrawal syndrome that compels relapse and deters abstinence. Many features of this syndrome are common across multiple drugs, involving both affective and physical symptoms. Some of the network signaling underlying withdrawal symptoms overlaps with activity that is associated with aversive mood states, including anxiety and depression. Given these shared features, it is not surprising that a particular circuit, the dorsal diencephalic conduction system, and the medial habenula (MHb) and interpeduncular nucleus (IPN), in particular, have been identified as critical to the emergence of aversive states that arise both as a result and, independently, of drug addiction. As the features of this circuit continue to be characterized, the MHb-IPN axis is emerging as a viable target for therapeutics to aid in the treatment of addiction to multiple drugs of abuse as well as mood-associated disorders. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.

Tobacco industry responsibility for butts: a Model Tobacco Waste Act

Cigarette butts and other postconsumer products from tobacco use are the most common waste elements picked up worldwide each year during environmental cleanups. Under the environmental principle of Extended Producer Responsibility, tobacco product manufacturers may be held responsible for collection, transport, processing and safe disposal of tobacco product waste (TPW). Legislation has been applied to other toxic and hazardous postconsumer waste products such as paints, pesticide containers and unused pharmaceuticals, to reduce, prevent and mitigate their environmental impacts. Additional product stewardship (PS) requirements may be necessary for other stakeholders and beneficiaries of tobacco product sales and use, especially suppliers, retailers and consumers, in order to ensure effective TPW reduction. This report describes how a Model Tobacco Waste Act may be adopted by national and subnational jurisdictions to address the environmental impacts of TPW. Such a law will also reduce tobacco use and its health consequences by raising attention to the environmental hazards of TPW, increasing the price of tobacco products, and reducing the number of tobacco product retailers.

Nicotine withdrawal

An aversive abstinence syndrome manifests 4-24 h following cessation of chronic use of nicotine-containing products. Symptoms peak on approximately the 3rd day and taper off over the course of the following 3-4 weeks. While the severity of withdrawal symptoms is largely determined by how nicotine is consumed, certain short nucleotide polymorphisms (SNPs) have been shown to predispose individuals to consume larger amounts of nicotine more frequently--as well as to more severe symptoms of withdrawal when trying to quit. Additionally, rodent behavioral models and transgenic mouse models have revealed that specific nicotinic acetylcholine receptor (nAChR) subunits, cellular components, and neuronal circuits are critical to the expression of withdrawal symptoms. Consequently, by continuing to map neuronal circuits and nAChR subpopulations that underlie the nicotine withdrawal syndrome--and by continuing to enumerate genes that predispose carriers to nicotine addiction and exacerbated withdrawal symptoms--it will be possible to pursue personalized therapeutics that more effectively treat nicotine addiction.

Reducing tobacco use and access through strengthened minimum price laws

Higher prices reduce consumption and initiation of tobacco products. A minimum price law that establishes a high statutory minimum price and prohibits the industry's discounting tactics for tobacco products is a promising pricing strategy as an alternative to excise tax increases. Although some states have adopted minimum price laws on the basis of statutorily defined price "markups" over the invoice price, existing state laws have been largely ineffective at increasing the retail price. We analyzed 3 new variations of minimum price laws that hold great potential for raising tobacco prices and reducing consumption: (1) a flat rate minimum price law similar to a recent enactment in New York City, (2) an enhanced markup law, and (3) a law that incorporates both elements.

Scientific overview: 2013 BBC plenary symposium on tobacco addiction

Nicotine dependence plays a critical role in addiction to tobacco products, and thus contributes to a variety of devastating tobacco-related diseases (SGR 2014). Annual costs associated with smoking in the US are estimated to be between $289 and $333 billion. Effective interventions for nicotine dependence, especially in smokers, are a critical barrier to the eradication of tobacco-related diseases. This overview highlights research presented at the Plenary Symposium of Behavior, Biology and Chemistry: Translational Research in Addiction Conference (BBC), hosted by the UT Health Science Center San Antonio, on March 9-10, 2013. The Plenary Symposium focused on tobacco addiction, and covered topics ranging from basic science to national policy. As in previous years, the meeting brought together globally-renowned scientists, graduate student recruits, and young scientists from underrepresented populations in Texas and other states with the goal of fostering interest in drug addiction research in young generations.

Benign ectopic submandibular thyroid with a normotopic multinodular goitre

Ectopic submandibular thyroid tissue is a rare entity and poses difficult diagnostic and management problems. The first case of ectopic submandibular thyroid with a normotopic multinodular goitre is presented

Renal transplantation: an analysis of 33 cases

Thirty-three patients with end-stage renal failure have had transplants over a three-year period, four patients receiving kidneys from siblings and the remainder cadaver organs. Twenty-seven kidneys survived with stable function for periods of six months to three years. Graft survival at one year was 85% and at two years 82%. One patient died and five were returned to dialysis. Complications included rejection episodes, technical problems, respiratory and wound infections, gastrointestinal disorders, and side effects of steroids.