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ObjectiveDescribe the landscape of tobacco-related topics, funders and institutional networks in Africa.Data sourcesWe searched PubMed, Embase and African Index Medicus for published articles from January 1996 to August 2018 in any language.Study selectionTwo researchers independently reviewed titles and abstracts for a focus on nicotine or tobacco product(s) and describe data or recommendations specific to Africa. Ultimately, 818 articles were identified.Data extractionThree independent coders conducted qualitative analyses of articles and extracted funders, study populations, countries of research focus, research topics, tobacco products, study design and data source. A bibliometric analysis estimated coauthorship networks between the countries of authors’ primary institutional affiliation.Data synthesisAll 54 African countries were represented in two or more articles. The coauthorship network included 2714 unique authors representing 90 countries. Most articles employed a cross-sectional study design with primary data collection, focused on cigarettes and studied use behaviour. Few articles examined tobacco farming or interventions for cessation or prevention. The most frequently cited funder was the US National Institutes of Health (27.2%). A range of coauthorship patterns existed between African institutions with some coauthoring with one institution while others coauthored with 761 institutions in other African countries.ConclusionsThe literature review identified the need for implementation research for tobacco control interventions and policies, economic and development impacts of tobacco use research, and tobacco industry and tobacco production and farming research. Numbers of research collaborations between institutions in Africa vary, suggesting the need for regional institutional capacity building.

IntroductionIllicit smokeless tobacco (ST) trade has seldom been documented despite ST use in at least 127 countries across the world. Based on non-compliance with packaging regulations, we report the proportion of illicit ST products from samples on sale in Bangladesh, India and Pakistan where 85% of global ST users reside.MethodsWe purchased unique ST products from tobacco sellers in two purposively selected administrative areas (division/district) in each of the three countries. The criteria to determine illicit ST products were based on country-specific legal requirements for ST packaging and labelling. These requirements included: ‘market retail price disclosure’, ‘sale statement disclosure’, ‘pictorial health warning (PHW) pertinence’, ‘appropriate textual health warning’ and ‘using misleading descriptors (MDs)’. Non-compliance with even one of the legal requirements was considered to render the ST product illicit.ResultsAlmost all ST products bought in Bangladesh and India were non-compliant with the local packaging requirements and hence potentially illicit, all products in Pakistan lacked desirable features. The most common feature missing was health warnings: 84% packs in Bangladesh, 93% in India, and 100% in Pakistan either did not have PHW or their sizes were too small. In Bangladesh, 61% packs carried MDs. In India and Pakistan, the proportions of such packs were 32% and 42%, respectively.ConclusionsWeak and poorly enforced ST control policies may be slowing the progress of tobacco control in South Asia. Standardised regulations are required for packaging and labelling ST. Improving compliance and reducing sale of cheap illicit products may require business licensing and market surveillance.

Antibiotics and drainage have largely replaced hepatic resection for the treatment of liver abscesses in the modern era; however, in cases caused by a rare strain of Klebsiella pneumoniaewith a hypermucoviscous phenotype, more aggressive hepatic resection may be required. The patient is a 34-year-old male who presented to Landstuhl Regional Medical Center with a week of epigastric pain. His workup revealed a 6 cm liver abscess with growth to 10 cm in 48 hours. He underwent multiple drainage procedures at Landstuhl and then was transferred to Walter Reed where further surgical drainage was performed. Initial cultures demonstrated K. pneumoniae.He clinically improved and was able to discharge after a 2 week hospitalization. His final remaining surgical drain was removed as an outpatient, but 48 hours after removal, he was admitted to the intensive care unit in septic shock. Imaging revealed a 12 cm liver abscess, and cultures verified hypermucoviscous Klebsiella. After multidisciplinary discussion and counseling, he underwent an open right partial hepatectomy. Postoperatively he gradually recovered from his sepsis and major operation and then returned to his home in Landstuhl. This is a case of a rare hypermucoviscous variant of K. pneumoniaecausing a liver abscess resistant to multiple drainage procedures, ultimately requiring open hepatic surgical resection for source control. This remains a last-resort option in the treatment of liver abscesses and should be considered early when caused by this rare strain of Klebsiella.

Survey results from MCP military surgeons and civilian host champions demonstrate that well-established MCP partnered programs align well with the guidelines set forth in the Blue Book. This preliminary survey can be used in future MCP collaborations.

Background: Elderly patients are underrepresented in studies demonstrating the advantages of laparoscopy for the management of colorectal diseases. Moreover, few studies have examined the robotic approach in this population. In this retrospective analysis, we compare outcomes for open, laparoscopic, and robotic approaches in elderly patients with nonmetastatic rectal cancer. Methods: The U.S. National Cancer Database was queried for patients aged ≥ 65 with nonmetastatic adenocarcinoma of the rectum who underwent surgical resection from 2010 to 2016. Groups were separated based on approach (open, laparoscopic, robotic). One–to-one nearest neighbor propensity score matching (PSM) ± 1% caliper was performed across surgical approach cohorts to balance potential confounding covariates. Kaplan–Meier estimation and Cox-proportional hazards regression were used to analyze the primary outcome of survival. Secondary outcomes were analyzed by way of logistic regression. Results: Inclusion criteria and PSM identified 1891 patients per approach (n= 5673). PSM provided adequate discrimination between cohorts (0.6 < AUC < 0.8), and potential confounding covariates did not significantly differ (respective P> 0.05). After PSM, robotic and laparoscopic approaches were associated with decreased odds of 90 day mortality compared to the open approach (P< 0.05). Compared to laparoscopy, a robotic approach was associated with increased odds of ≥ 12 regional lymph nodes examined and negative circumferential resection margin (P< 0.05). No differences were seen in 30 day or 90 day mortality between robotic and laparoscopic approaches. Cox proportional hazards regression showed that both robotic and laparoscopic approaches were significantly associated with decreased mortality hazards relative to open. Conclusion: Our study demonstrates that in elderly patients, minimally invasive surgery for rectal adenocarcinoma was associated with equivalent or improved short- and long-term mortality over open surgery. Compared to laparoscopy, the robotic approach showed no survival disadvantage and greater odds of an appropriate oncological resection. Our study adds evidence to the conclusion that robotic rectal surgery can be safely performed in patients regardless of age.

Background: Crohn’s disease has historically been managed medically with sparing use of surgical resection. With the development of strictures or fistulas, surgical management such as an ileocecal resection may become necessary. Minimally invasive options such as laparoscopic and robotic-assisted techniques are alternatives to open surgery. The purpose of this study was to evaluate the safety of minimally invasive surgery for Crohn’s disease. Methods: We performed a retrospective review of the National Surgical Quality Improvement Program (NSQIP) database to select 5158 patients with Crohn’s disease who underwent ileocecal resection (open, laparoscopic, or robotic-assisted). Preoperative, perioperative, and 30-day postoperative outcomes were compared between the groups using both univariate and multivariate logistical regression models. SAS was used for data analysis with p< 0.05 considered significant. Results: The three treatment groups (open, laparoscopic, and robotic-assisted ileocecal resection) had 30-day postoperative outcomes reported in NSQIP. The average BMI was 25 kg/m2and the average age was 41. The rate of anastomotic leaks was significantly higher in the open surgery group compared to the minimally invasive groups (p= 0.001). The open surgery group had a significantly higher reoperation rate (p= 0.0002) and wound infection rate (p< 0.0001). The robotic-assisted group had significantly longer operative times compared to the laparoscopic and open groups (p< 0.0001). Conclusions: The decision to operate on a patient with Crohn’s disease involves selecting an approach based on patient factors, surgeon preference, and availability of equipment. When evaluating the short-term postoperative outcomes in patients that have undergone ileocecal resection for management of Crohn’s, minimally invasive techniques have had a lower incidence of wound infections, anastomotic leaks, and re-intervention in carefully selected patients. This retrospective review of a large national database demonstrates the efficacy of minimally invasive techniques in managing Crohn’s disease in selected patients.

Data visualization techniques were used to ascertain (1) site‐specific effects of cigarette smoking on the periodontium compared to never‐smokers; (2) patterns of site‐specific effects by age among current and never‐smokers using contour maps. Data from 10,713 dentate participants aged ≥30 years in NHANES 2009‐2014 were used. Pocket depth (PD) and clinical attachment level (CAL) for six sites/tooth were ascertained by smoking status and plotted using contour maps to identify new patterns. In the overall sample, 19% (n= 2015) were current smokers and 56% (n= 6013) were never‐smokers. Contour maps of the overall sample showed teeth/sites most affected with mean PD > 2.1 mm were molars (2,3,15,18,19,30,31) in mesio‐lingual (ML) and disto‐lingual (DL) sites. Most affected sites for current smokers were interproximal sites of most posterior teeth. Among never‐smokers, fewer teeth/sites were affected with PD > 2.1 mm, whereas among smokers, number of affected teeth/sites increased with age. Overall, teeth/sites most affected with mean CAL≥2.1 mm were noted in 2,3(ML), 3(DL), 14(DF, DL), 15(MF, ML), 18(ML), 19(DL, ML), and 30‐31(ML, DL) with upper anterior teeth least affected. Among current smokers, several teeth/sites were affected (CAL≥2.1 mm): 2,3(all six sites), 4(ML, DL), 9(ML), 11‐21(DL), 13‐18(DF, ML, MIL, DL), 19‐20(DF, ML, MIL), 14‐18(MIF), 21(MIF, ML, DL), 22(MF), 23‐27(MIL), 24‐26(MIL, MF, DF in 26), 27(MF), 28(MF, ML, DL), 29‐31(all 6 sites except MIF 30,31). As age increased, more teeth/sites were affected among smokers and by the 5th decade nearly all teeth/sites had CAL≥2.0 mm. Contour mapping identifies patterns and dramatically visualizes the substantial periodontal site‐specific differences. Current smokers had more affected teeth and/or periodontal sites with a different contour pattern than never‐smokers.

Background: This study examined utilization and conversion rates for robotic and laparoscopic approaches to non-metastatic rectal cancer. Secondary aims were to examine short- and long-term outcomes of patients who underwent conversion to laparotomy from each approach. Methods: The National Cancer Database (NCDB) was reviewed for all cases of non-metastatic adenocarcinoma of the rectum or rectosigmoid junction who underwent surgical resection from 2010 to 2016. Utilization rates of robotic, laparoscopic, and open approaches were examined. Patients were split into cohorts by approach. Subgroup analyses were performed by primary tumor site and surgical procedure. Multivariable analysis was performed by multivariable logistic regression for binary outcomes and multivariable general linear models for continuous outcomes. Survival analysis was performed by Kaplan–Meier and multivariable cox-proportional hazards regression. Results: From 2010 to 2016, there was a statistically significant increase in utilization of the robotic and laparoscopic approaches over the study period and a statistically significant decrease in utilization of the open approach. The conversion rates for robotic and laparoscopic cohorts were 7.0% and 15.7%, p< 0.0001. Subgroup analysis revealed statistically lower conversion rates between robotic and laparoscopic approaches for rectosigmoid and rectal tumors and for LAR and APR. Converted cohorts had statistically significant higher odds of short term mortality than the non-converted cohorts (p< 0.05).Laparoscopic conversion had statistically higher odds of positive margins (p< 0.0001) and 30-day unplanned readmission (p< 0.0001) than the laparoscopic non-conversion. Increased adjusted mortality hazard was seen for converted laparoscopy relative to non-converted laparoscopy (p= 0.0019). Conclusion: From 2010 to 2016, there was a significant increase in utilization of minimally invasive approaches to surgical management of non-metastatic rectal cancer. A robotic approach demonstrated decreased conversion rates than a laparoscopic approach at the rectosigmoid junction and rectum and for LAR and APR. Improved outcomes were seen in the minimally invasive cohorts compared to those that converted to laparotomy.

Introduction Ulcerative colitis (UC) is a chronic inflammatory intestinal disorder that can be managed surgically with a proctocolectomy. Minimally invasive techniques such as laparoscopic or robotic-assisted surgery are available based on the surgeon’s preference and familiarity. To date, there is a paucity of literature evaluating the safety of these techniques in comparison to the open approach in patients with UC.Methods We surveyed the National Surgical Quality Improvement Program (NSQIP) database to select patients with the diagnosis of UC who underwent either robotic, laparoscopic, or open proctocolectomy between 2012 and 2017. A total of 2129 patients were included in the study. The 30-day postoperative outcomes were compared using multivariable logistic regression models after adjusting for confounding variables. The confounding variables were defined as any preoperative variable that was associated with the type of procedure.Results The 30-day postoperative outcomes reported in the NSQIP database were reviewed for each of the treatment groups (open, laparoscopic, and robotic). The anastomotic leak rate was significantly higher in the open group (P= .022). The robotic and laparoscopic groups had significantly fewer occurrences of postoperative ileus (P= .0006) and wound infections (P< .0001). There were significantly more strokes, cardiac events, and pulmonary events in the open surgical group. Operative time was significantly shorter in the open group (P< .0001). Reintervention rates were not significantly different among the groups.Conclusions Minimally invasive proctocolectomy has significantly fewer postoperative complications compared with open proctocolectomy for UC. There is no significant difference in the postoperative outcomes between robotic-assisted and laparoscopic proctocolectomy.

Background Data regarding the effect of conversion from minimally invasive surgery (MIS) to laparotomy in rectal cancer is limited. This study examines the impact of conversion from laparoscopic or robotic-assisted techniques to open resection on oncologic outcomes in a large population database.Methods The National Cancer Database from 2010 to 2016 was reviewed for all cases of invasive adenocarcinoma of the rectum or rectosigmoid junction managed surgically. Patients were divided into 3 cohorts by approach: laparoscopic/robotic (MIS), converted proctectomy (CP), and open proctectomy (OP). Kaplan–Meier estimation was used for unadjusted survival analysis, followed by adjusted multivariable Cox-Proportional Hazards regression. Secondary outcomes were analyzed by multivariable logistic regression.Results The inclusion criteria identified 57 574 patients cases of adenocarcinoma of the rectum managed surgically. Of these patients, 23 579 (41.0%) underwent MIS, 3591 (6.2%) CP, and 30 404 (52.8%) OP. Five-year overall survival was greater in the MIS (70.4%) versus CP and OP (64.4% and 61.4%). No differences were detected for positive margins, 30-day, or 90-day mortality between CP and OP. MIS and CP approaches were significantly associated with increased odds of 12 or more regional lymph nodes examined and decreased overall mortality hazard compared with OP (all respective significant P< .05).Discussion While similar odds of positive margins and short-term mortality is seen in patients whose procedure converts to laparotomy compared with planned laparotomy, both short-term and long-term oncologic benefit is seen in those who undergo a minimally invasive approach. Thus, a minimally invasive approach should be attempted for patients with rectal cancer.

Throughout much of the 20thcentury, cigarette manufacturers have sponsored sporting events and used sports figures in advertising and marketing their products. The United States Tobacco Company (UST) became a sponsor of the 1980 Winter Olympic Games in Lake Placid, New York, allowing the company to place the Olympic emblem on their television and print advertisements and on product packages. This paper reviews the history of UST’s 1980 Olympic sponsorship using records from the IOC, the Lake Placid organising committee and internal tobacco industry documents. At the time, UST was seeking to expand the market for smokeless tobacco products, experimenting with new products and portraying their products as an alternative to smoking. At the same time, commercial sponsorship was becoming increasingly important to the future of the Games. At the time, the International Olympic Committee (IOC) was struggling to implement a policy prohibiting tobacco sponsorship of the Olympic Games. This episode was to be the last time a tobacco company was named an official sponsor of the Olympic Games. However, while subsequent editions of the Olympic Games have adopted policies restricting tobacco industry sponsorship, the reach of these policies is limited across any Olympic organisations. The lack of a comprehensive policy on tobacco advertising and sponsorship associated with the Olympics continues to pose a challenge to efforts to remove tobacco from the Games.

BackgroundLung cancer is substantially attributable to smoking, but detailed related estimates on smoking-attributable expenditure (SAE) in China are not available yet, which could inform tobacco control and cancer prevention initiatives.MethodsA prevalence-based approach was adopted to estimate the total SAE, including direct expenditure (medical and non-medical) and indirect cost (disability and premature death). Detailed per-patient data on direct expenditure and work-loss days were acquired from a unique multicentre survey in China. Other parameters were from literatures and official reports.ResultsThe total estimated SAE of lung cancer was US$5249 million in China in 2015 (0.05 % of gross domestic product for China). The estimated direct SAE was US$1937 million (36.9 % of the total SAE), accounting for 0.29 % of total healthcare expenditure for China. The medical and non-medical direct expenditures were US$1749 million and US$188 million, respectively. The estimated indirect cost was US$3312 million (63.1 % of the total SAE), including US$377 million due to disability and US$2935 million due to premature death. The SAE increased with age, peaking at 60–64 years (US$1004 million), and was higher among men, in urban areas and in eastern China. If smoking prevalence was reduced to 20%, as is the goal of Healthy China 2030, the total SAE would be decreased by 4.9 %.ConclusionsSmoking-attributable economic burden caused by lung cancer was substantial in China in 2015, and will continue increasing given current trends in lung cancer. However, future economic burden can be prevented with implementation of effective tobacco control and other interventions.

In the 60th year since the publication of The Principles of Humane Experimental Techniqueby W.M.S. Russell and R.L. Burch, we visited the W.M.S. and Claire Russell Archive at the University of Nottingham to discover, or confirm, answers to certain questions: the origins of the UFAW project which led to its writing; the relationship between Russell and Burch; the project plan; the origin of the Three Rs (Replacement, Reduction, Refinement) concept; the drafting, publication and response to the appearance of the book; and the future careers of its authors. We report on our findings, though many other questions have yet to be answered.

BackgroundUnderstanding disparities in the burden of cancer attributable to smoking is crucial to inform and improve tobacco control measures. In this report, we estimate the population attributable fraction (PAF) of cancers deaths attributable to smoking at the national and provincial levels in China.MethodsUsing cancer mortality data from 978 counties, smoking data from a nationwide survey and relative risks from a prospective study of 0.5 million adults in China, we calculated the absolute (non-standardised) and standardised numbers and proportions of cancer deaths among adults 30 years and older attributable to active and second-hand smoking in 2014 across all 31 provinces in Mainland China.ResultsThe estimated number of cancer deaths attributable to smoking in China in 2014 was 342 854 among men and 40 313 among women, of which second-hand smoking accounted for 1.8% and 50.0%, respectively. Among men, the absolute PAF in China was 23.8%, ranging from 14.6% in Xinjiang to 26.8% in Tianjin; the overall standardised PAF was 22.2%, ranging from 15.7% in Xinjiang to 26.0% in Guizhou. Among women, the overall absolute and standardised PAFs were 4.8% and 4.0%, ranging from 1.8% and 1.6% in Jiangxi to 14.9% and 9.6% in Heilongjiang, respectively. Overall, provinces with the highest standardised PAFs among men were located in Southwest China and among women in the Northeast.ConclusionsComprehensive smoke-free policies in China should expand to all provinces, notably those with a higher burden of cancer attributable to smoking, instead of being mostly limited to Beijing and some other metropolitan areas.

BackgroundSecondhand smoke (SHS) exposure during pregnancy increases the risk of infant stillbirth, congenital malformations, low birth weight and respiratory illnesses. However, little is known about the extent of SHS exposure during pregnancy. We assessed the prevalence of SHS exposure in pregnant women in low-income and middle-income countries (LMICs).MethodsWe used Demographic and Health Survey data collected between 2008 and 2013 from 30 LMICs. We estimated weighted country-specific prevalence of SHS exposure among 37 427 pregnant women. We accounted for sampling weights, clustering and stratification in the sampling methods. We also explored associations between sociodemographic variables and SHS exposure in pregnant women using pairwise multinomial regression model.FindingsThe prevalence of daily SHS exposure during pregnancy ranged from 6% (95% CI 5% to 7%) (Nigeria) to 73% (95% CI 62% to 81%) (Armenia) and was greater than active tobacco use in pregnancy across all countries studied. Being wealthier, maternal employment, higher education and urban households were associated with lower SHS exposure in full regression models. SHS exposure in pregnant women closely mirrors WHO Global Adult Tobacco Survey male active smoking patterns. Daily SHS exposure accounted for a greater population attributable fraction of stillbirths than active smoking, ranging from 1% of stillbirths (Nigeria) to 14% (Indonesia).InterpretationWe have demonstrated that SHS exposure during pregnancy is far more common than active smoking in LMICs, accounting for more stillbirths than active smoking. Protecting pregnant women from SHS exposure should be a key strategy to improve maternal and child health.

ABSTRACTThe mechanisms behind the Warburg effect in mammalian cells, as well as for the similar Crabtree effect in the yeast Saccharomyces cerevisiae, are still a matter of debate: why do cells shift from the energy-efficient respiration to the energy-inefficient fermentation at high sugar concentration?This review reports on the strong similarities of these phenomena in both cell types, discusses the current ideas, and provides a novel interpretation of their common functional mechanism in a dynamic perspective. This is achieved by analysing another phenomenon, the sugar-induced-cell-death (SICD) occurring in yeast at high sugar concentration, to highlight the link between ATP depletion and cell death.The integration between SICD and the dynamic functioning of the glycolytic process, suggests that the Crabtree/Warburg effect may be interpreted as the avoidance of ATP depletion in those conditions where glucose uptake is higher than the downstream processing capability of the second phase of glycolysis. It follows that the down-regulation of respiration is strategic for cell survival allowing the allocation of more resources to the fermentation pathway, thus maintaining the cell energetic homeostasis.

ObjectivesTo systematically review and meta-analyse the studies investigating the association between smokeless tobacco (SLT) use and all-cause mortality and cause-specific mortality outcomes among adult users of SLT and estimate the number of attributable deaths worldwide.MethodsRandom-effects meta-analysis was used to estimate the pooled risk of death due to SLT use. Population attributable fractions were derived and used to calculate the number of attributable deaths. Observational studies published upto 2015 were identified through MEDLINE, IndMED, Google Scholar and other databases. Data on the prevalence of SLT use was obtained from latest reports or national surveys. Data on the disease burden were obtained from the Global Burden of Disease Study. Hospital-based or community-based case–control and cohort studies that adjusted for the smoking status were included.Results16 studies that provided estimates for mortality due to all cause, all cancer, upper aerodigestive tract (UADT) cancer, stomach cancer, cervical cancer, ischaemic heart disease (IHD) and stroke were included. A significant association was found for mortality due to all cause (1.22; 1.11–1.34), all cancer (1.31; 1.16–1.47), UADT cancer (2.17; 1.47–3.22), stomach cancer (1.33; 1.12–1.59), cervical cancer (2.07; 1.64–2.61), IHD (1.10; 1.04–1.17) and stroke (1.37; 1.24–1.51). Subgroup analysis showed major regional differences. Globally, the number of attributable deaths from all-cause mortality was 652 494 (234 008–1 081 437), of which 88% was borne by the South-East Asian region.ConclusionsSLT is responsible for a large number of deaths worldwide with the South-East Asian region bearing a substantial share of the burden.

For over half a century, the U.S. National Cancer Institute (NCI) has supported research on tobacco and health, which has contributed to reductions in tobacco-caused morbidity and mortality in the U.S. But while tobacco use has been slowly declining in most high-income nations, including the US, it has continued to increase in other parts of the globe. Of the 800 million adult men who currently smoke cigarettes, over 80% are in low- and middle-income countries (LMICs), and these countries will bear an increasing share of the health and economic burden of tobacco use. At the same time, there are additional challenges to implementing tobacco control programs in LMICs, including a diversity of tobacco products, limited capacity and resources for tobacco control, and competing health priorities. While a large body of evidence has been generated around tobacco dependence treatment and other measures in high-income countries, this work is only partly applicable to many LMICs. In this paper we focus on research needs and opportunities around tobacco cessation interventions for LMICs, highlighting four areas: understanding diverse tobacco products, development of low-cost cessation interventions, integrating tobacco cessation into health systems, and understanding tobacco use behaviors across different contexts. Expanding tobacco control research and research capacity in LMICs is crucial to reducing tobacco use and cancer rates worldwide. Furthermore, research conducted in countries around the world can yield important insights for understanding tobacco use behaviors and the effectiveness of tobacco control interventions in the US.

Addictive, toxic, and carcinogenic constituents present in smokeless tobacco (SLT) products are responsible for the harmful effects associated with SLT use. There are limited data on levels of such constituents in SLT products used in Africa, a region with high prevalence of SLT use and the associated morbidity and mortality. Manufactured and custom-made SLT products were purchased from five African countries (South Africa, Uganda, Mauritania, Nigeria, and Zambia) using a standard approach for sample collection, labeling, and storage. Moisture content, pH, total and unprotonated (biologically available) nicotine, five tobacco-specific N-nitrosamines (TSNA), 10 polycyclic aromatic hydrocarbons (PAH), five metals and metalloids (As, Cd, Cr, Ni, and Pb), nitrate, and nitrite were analyzed. A total of 54 samples representing 15 varieties of manufactured SLT products and 13 varieties of custom-made SLT products were purchased and analyzed. In all samples, the total nicotine ranged from 1.6 to 20.5 mg/g product and unprotonated nicotine accounted for 5.3–99.6% of the total nicotine content. The sum of all five TSNA ranged from 1.6 to 100 μg/g product, with significant within-country variations observed across both the manufactured and custom-made varieties. Significant variations were also found for PAH, metals and metalloids, nitrates, and nitrites. This is the most comprehensive report on the chemical profiling of products from African countries. This is also the first study illustrating the variability of harmful constituents within the same types and brands of African SLT. Our findings emphasize the need for consumer education and interventions to reduce SLT use in Africa. The data reported here can be useful to regulators in considering measures to prevent the occurrence of high levels of known toxicants and carcinogens in manufactured products.

A personal narrative is presented which explores the author's experiences with small dogs in animal shelter houses.

Bioethicists have articulated an ideal of shared decision making between physician and patient, but in doing so the role of clinical uncertainty has not been adequately confronted. In the face of uncertainty about the patient's prognosis and the best course of treatment, many physicians revert to a model of nondisclosure and nondiscussion, thus closing off opportunities for shared decision making. Empirical studies suggest that physicians find it more difficult to adhere to norms of disclosure in situations where there is substantial uncertainty. They may be concerned that acknowledging their own uncertainty will undermine patient trust and create additional confusion and anxiety for the patient. We argue, in contrast, that effective disclosure will protect patient trust in the long run and that patients can manage information about uncertainty. In situations where there is substantial uncertainty, extra vigilance is required to ensure that patients are given the tools and information they need to participate in cooperative decision making about their care.

Causation is an essential concept in epidemiology, yet there is no single, clearly articulated definition for the discipline. From a systematic review of the literature, five categories can be delineated: production, necessary and sufficient, sufficient-component, counterfactual, and probabilistic. Strengths and weaknesses of these categories are examined in terms of proposed characteristics of a useful scientific definition of causation: it must be specific enough to distinguish causation from mere correlation, but not so narrow as to eliminate apparent causal phenomena from consideration. Two categories--production and counterfactual--are present in any definition of causation but are not themselves sufficient as definitions. The necessary and sufficient cause definition assumes that all causes are deterministic. The sufficient-component cause definition attempts to explain probabilistic phenomena via unknown component causes. Thus, on both of these views, heavy smoking can be cited as a cause of lung cancer only when the existence of unknown deterministic variables is assumed. The probabilistic definition, however, avoids these assumptions and appears to best fit the characteristics of a useful definition of causation. It is also concluded that the probabilistic definition is consistent with scientific and public health goals of epidemiology. In debates in the literature over these goals, proponents of epidemiology as pure science tend to favour a narrower deterministic notion of causation models while proponents of epidemiology as public health tend to favour a probabilistic view. The authors argue that a single definition of causation for the discipline should be and is consistent with both of these aims. It is concluded that a counterfactually-based probabilistic definition is more amenable to the quantitative tools of epidemiology, is consistent with both deterministic and probabilistic phenomena, and serves equally well for the acquisition and the application of scientific knowledge.

Flow‐cytometric analysis was employed to investigate growth dynamics of a yeast cell population immobilised in an insolubilised gelatin gel by means of the quantitative determination of the average protein content per cell. This analysis was carried out on both the immobilised cell population considered as a whole and the subpopulations colonising the gelatin matrix at different depths. The results show that growth of the gelatin‐immobilised yeast population was affected by the existence of a gradient of nutrient concentrations through the matrix and are in agreement with the unsteady‐state diffusion model employed for the description of glucose transfer in the gel.