Results from a cancer screening trial indicate that consistent heavy alcohol intake and higher average lifetime drinking are associated with increased risk.
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Studies have demonstrated a link between alcohol consumption and an elevated risk of colorectal cancer. New research now reveals that higher lifetime alcohol consumption is also associated with a higher risk, especially for rectal cancer, and that quitting drinking can lower a person’s risk. The findings are published by Wiley online in CANCER, a peer-reviewed journal of the American Cancer Society.
When investigators analysed data on US adults enrolled in the National Cancer Institute (NCI) Prostate, Long, Colorectal, and Ovarian (PLCO) Cancer Screening Trial who did not have cancer at baseline, they observed that 1679 colorectal cancer cases occurred among 88 092 participants over 20 years of follow-up.
Current drinkers with an average lifetime alcohol intake of ≥ 14 drinks per week (heavy drinkers) had a 25% higher risk of developing colorectal cancer and a 95% higher risk of developing rectal cancer compared with those with an average lifetime alcohol intake of < 1 drink per week (light drinkers).
When further considering drinking consistency, heavy drinking throughout adulthood was linked to a 91% higher risk of colorectal cancer compared with consistent light drinking. In contrast, no evidence of increased colorectal cancer risk was observed among former drinkers, and former drinkers had lower odds of developing noncancerous colorectal tumours, or adenomas (which may go on to become cancerous) than current drinkers averaging < 1 drink per week, suggesting that alcohol cessation may lower individuals’ risks. These data were limited, however.
The association between alcohol consumption and increased risks observed in this and other studies might be explained by carcinogens produced from alcohol metabolism or alcohol’s effects on gut microbes. Additional studies are needed to test whether these mechanisms are involved.
“Our study is one of the first to explore how drinking alcohol over the life course relates to both colorectal adenoma and colorectal cancer risk. While the data on former drinkers were sparse, we were encouraged to see that their risk may return to that of the light drinkers,” said co–senior author Erikka Loftfield, PhD, MPH, of the NCI, part of the National Institutes of Health.
The new device sprays mist to treat deep wound infections without causing kidney damage
Hongmin Sun demonstrating the new device.
A University of Missouri researcher has unveiled a safer, smarter way to fight drug-resistant infections. Hongmin Sun, an associate professor in the School of Medicine, demonstrated that a spray-mist device can deliver last-resort antibiotics directly into infected tissue without the harmful side effects often caused by delivery via the bloodstream.
In a recent study, researchers worked with an industry partner to use a needle-free device to treat methicillin-resistant Staphylococcus aureus (MRSA), a dangerous bacterium that has become resistant to many common antibiotics.
The device successfully delivered the common last-resort antibiotic vancomycin deep into infected tissue without typical side effects such as kidney damage. Unlike topical creams or ointments that are easily wiped away or bloodstream delivery that risks organ damage, the spray-mist technology pushed the medicine through the skin to successfully treat the infection.
Sun collaborated with former Mizzou researcher Lakshmi Pulakat, now a professor of medicine at Tufts University, and Droplette Inc. to use the patented device for antibiotic delivery. The findings pave the way for future clinical trials as researchers seek FDA approval.
The team is hopeful the spray-mist device might one day be used in wound care in challenging settings.
“Whether it’s people with diabetic foot ulcers or soldiers hurt in battle, we wanted to come up with a new approach to treat these severely infected wounds in a more targeted way,” Sun said. “This can be a game-changing therapy for treating those with severely infected wounds.”
Pulakat said the technology is an example of compassionate care.
“This method of delivering last-resort antibiotics could prevent countless amputations and help save lives,” she said. “Dr. Sun is an internationally recognized expert in the field of pathogenic microbiology, and our collaboration with an industry partner has helped make this translational research possible.”
Humans’ exposure to high temperature burn injuries may have played an important role in our evolutionary development, shaping how our bodies heal, fight infection, and sometimes fail under extreme injury, according to new research.
For more than one million years, the control of fire has powered human success, from cooking and heating to technology and industry, driving genetic and cultural evolution and setting us apart from all other species. But this relationship has also exposed humans to high temperature injuries at a scale unmatched in the natural world.
Humans burn themselves – and survive burns – with a frequency likely much greater than any other animal. Most animals avoid fire completely, while in contrast, humans live alongside fire and most humans will experience minor burns throughout their lives.
A new study published in BioEssays, led by Imperial College London researchers, suggests that this increased exposure to burn injuries may have driven notable genetic adaptations which differentiated humans from other primates and mammals. This may also explain both beneficial and maladaptive responses to severe burn injury.
Burn injuries exist on a spectrum of severity, with most small injuries healing on their own while severe burns can lead to lifelong disability or death. Burns damage the skin, the body’s main protective barrier against infection, sometimes over large areas of the body. The longer the skin is damaged, the greater the risk that bacteria can enter the body and cause overwhelming infection.
The researchers argue that natural selection would have favoured traits that helped humans survive small to moderate burns. These may include faster inflammation, faster wound closure (to prevent infection) and stronger pain signals.
However, while these traits are helpful for less severe injuries, they can become harmful for large burns, which may explain why modern humans can experience extreme inflammation, scarring, and organ failure from major burns.
Using comparative genomic data across primates, the researchers found examples of genes associated with burn injury responses which show signs of accelerated evolution in humans. These genes are involved in wound closure, inflammation and immune system response – likely helping to rapidly close wounds and fight infection; a major complication after burn injury, particularly before the widespread use of antibiotics.
These findings support the theory that exposure to burn injuries may have been a notable force on the evolution of humans.
Dr Joshua Cuddihy, lead author for the study, and Honorary Clinical Lecturer in Imperial’s Department of Surgery and Cancer, said: “Burns are a uniquely human injury. No other species lives alongside high temperatures and the regular risk of burning in the way humans do.
“The control of fire is deeply embedded in human life — from a preference for hot food and boiled liquids to the technologies that shape the modern world. As a result, unlike any other species, most humans will burn themselves repeatedly over their lifetime, a pattern that likely extends back over a million years to our earliest use of fire.
“Our research suggests that natural selection favoured traits that improved survival after smaller, more frequent burn injuries. However, those same adaptations may have come with evolutionary trade-offs, helping to explain why humans remain particularly vulnerable to the complications of severe burns.”
The control of fire has powered human success for more than one million years
The study’s novel perspective on human evolution, which could reshape our understanding of modern burn care and human biology, was made possible through interdisciplinary collaboration between clinicians and researchers.
Professor Armand Leroi, Professor of Evolutionary Developmental Biology in Imperial’s Department of Life Sciences, said: “What makes this theory of burn selection so exciting to an evolutionary biologist is that it presents a new form of natural selection – one, moreover, that depends on culture. It is part of the story of what makes us human, and a part that we really did not have any inkling of before.”
Yuemin Li, PhD student at Queen Mary University of London, said: “Our study provides compelling evidence that humans have unique adaptive mutations in several key genes associated with burn injury response.
“These findings could allow us to explore in future research how genetic variations in different groups impact burn injury response, potentially explaining why some patients heal well or poorly after a burn.”
Unlike other wounds from cuts or bites which would have also led to infections, the increased lifetime risk of burns experienced by humans and their hominin ancestors is unique as they are the only species to regularly experience burn injuries and survive them.
The researchers’ findings could change how we study burn injuries, design treatments, and interpret complications of burns. It may also explain why translating results on burn injuries from animal models to humans is often ineffective.
Declan Collins, Consultant in Plastic and Reconstructive Surgery at Chelsea and Westminster Hospital NHS Foundation Trust, said: “Understanding the evolutionary drivers that cause genetic change is an important step in burn research that will influence the way in which we look at scar formation and wound healing.
“The genetic basis for scarring variation in humans and response to tissue injury is still poorly understood, and this work will provide new angles for future research.”
Historical data indicate that men develop coronary heart disease (CHD) 10 years before women. A recent study in the Journal of the American Heart Association indicates that this sex gap still remains.
Investigators analysed data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, in which US adults aged 18–30 years enrolled in 1985–1986 and were followed through August 2020.
Among 5112 participants (54.5% female, 51.6% Black) with an average age of 24.8 years at enrolment and a median follow-up of 34.1 years, men had a significantly higher cumulative incidence of cardiovascular disease. They had higher cumulative incidence rates of the cardiovascular disease subtypes of CHD and heart failure compared with women, but no difference in stroke.
Men reached a 5% incidence of cardiovascular disease 7.0 years earlier than women (50.5 versus 57.5 years). CHD was the most frequent cardiovascular disease subtype, and men reached a 2% incidence 10.1 years earlier than women. There were no significant differences in the age at which men and women reached a 2% incidence for stroke (57.5 versus 56.9 years) or a 1% incidence for heart failure (48.7 versus 51.7 years)
Differences emerged in the fourth decade of life and were not explained after accounting for differences in cardiovascular health.
“Sex differences in cardiovascular disease risk are apparent by age 35, highlighting the importance of initiating risk assessment and prevention strategies in young adulthood,” said corresponding author Alexa Freedman, PhD, of the Northwestern University Feinberg School of Medicine.
Large study of patients in the US, Colombia, Nigeria and India finds symptom burden highest in high-income countries
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Patients with long COVID-19 in the US report far higher rates of brain fog, depression and cognitive symptoms than patients in countries such as India and Nigeria, according to a large international study led by Northwestern Medicine.
The authors note that higher reported symptom burden in the US may reflect lower stigma and greater access to neurological and mental health care, rather than more severe disease.
The study, the first cross-continental comparison of long COVID neurological manifestations, tracked more than 3100 adults with long COVID evaluated at academic medical centres in Chicago; Medellín, Colombia; Lagos, Nigeria; and Jaipur, India.
Among patients who were not hospitalised during their COVID infections (the majority in the study), 86% in the US reported brain fog, compared with only 63% in Nigeria, 62% in Colombia and 15% in India. Rates of psychological distress showed a similar pattern: Nearly 75% of non-hospitalised patients in the US reported symptoms of depression or anxiety, compared with only 40% in Colombia and fewer than 20% in Nigeria and India.
“It is culturally accepted in the US and Colombia to talk about mental health and cognitive issues, whereas that is not the case in Nigeria and India,” said Dr Igor Koralnik, senior study author and chief of neuro-infectious disease and global neurology at Northwestern University Feinberg School of Medicine.
“Cultural denial of mood disorder symptoms as well as a combination of stigma, misperceptions, religiosity and belief systems, and lack of health literacy may contribute to biased reporting. This may be compounded by a dearth of mental health providers and perceived treatment options in those countries.”
Brain fog, fatigue, myalgia (muscle pain), headache, dizziness and sensory disturbances (such as numbness or tingling) were the most common neurological symptoms across all countries
Insomnia was reported by nearly 60% of non-hospitalised US patients, compared with roughly one-third or fewer of patients in Colombia, Nigeria and India
Statistical clustering showed clear separation between high- and upper-middle-income (US, Colombia) and lower-middle-income (Nigeria, India) countries
Building on this work, Koralnik and his international collaborators are now studying cognitive rehabilitation treatments for long COVID brain fog in Colombia and Nigeria, using the same protocols developed for patients treated at the Shirley Ryan AbilityLab in Chicago.
