The presence of food-specific IgA antibodies in the gut does not prevent peanut or egg allergies from developing in children, according to a Northwestern Medicine study published in Science Translational Medicine.
Scientists examined stool samples from more than 500 infants across the country and found that the presence of Immunoglobulin A, the most common antibody found in mucous membranes in the digestive tract, does not prevent peanut or egg allergies from developing later in life.
This discovery calls into question the role of Immunoglobulin A, or IgA, which was previously thought to be a protective factor against the development of food allergies.
While prior research had shown IgA could bind to and neutralide toxins and bacteria in the body, there was inconclusive evidence that IgA could do the same for food allergens, said Stephanie Eisenbarth, MD, PhD, senior author of the study.
“We were able to collaborate with different groups around the country to look at a number of different cohorts of children and young adults to ask: ‘Does the presence of IgA to peanut tell us that the person is tolerant to peanut?’,” said Eisenbarth. “We found that there really was no difference between kids who had peanut allergies and children who didn’t, and the same is true with egg allergies.”
The findings come as rates of allergies in children continue to climb: According to data from the Centers for Disease Control and Prevention, the number of children with allergies has more than doubled in the last 20 years.
Future directions for research will center on understanding the role IgA plays in people who have undergone immunotherapy and developed a tolerance to food allergens, Eisenbarth said.
After nearly three years of its harsh and extremely unpopular zero-COVID policy, the Chinese government announced on Wednesday the suspension of key parts of the contentious restrictions.
One of the ways some Chinese people expressed relief at the news was to go to the social media account of Dr Li Wenliang, the whistleblowing doctor who warned of the emerging coronavirus Wuhan and who was himself one of the virus’s early victims.
According to BBC News, they left messages “as if stopping by the graveside of a family elder” in which they shared their feelings.
“On the train, I suddenly remembered you and burst into tears. Dr Li, it’s over now, it’s dawn. Thank you,” read one message.
Another wrote: “I’ve come to see you and let you know – the dust has settled. We’re reopening.”
Chinese authorities punished the 33-year-old ophthalmologist for spreading “false statements”. He later died from COVID as he battled to save patients, prompting an outpouring of public grief and anger.
Xi Jinping’s campaign of zero-COVID aimed to completely eradicate the virus in China. The leadership hailed it as a success while other countries battled with surges of infections and deaths. Crucially, however, the policy made no use of Western-developed vaccines, mainly relying on the Chinese-developed and produced Sinovac.
Thus, with the lifting of the strictest parts of zero-COVID, people turned Dr Li’s page into a place to express their frustrations, hopes and grief. They also remembered his heroism in the face of authority.
“Those who blow the whistle are always worth remembering,” wrote one user. “I look forward to a more transparent society.”
China’s zero-COVID policy did appear to keep the country safe from the pandemic. There were 5200 deaths officially recorded in the pandemic while the US has recorded over one million.
The zero-COVID policy did not come without other costs. Sudden lockdowns saw people unable to get food. People testing positive for COVID were prevented from being with their families and were forced into centralised quarantine facilities. Gatherings and travel were subject to restriction.
Recently, workers broke out of a Foxconn factory which was supposed to be locked down for a quarantine. The event made international headlines as the authorities engaged in a manhunt for the escapees.
Some questioned whether the restrictions had been worth it.
“I took the subway this morning and for the first time did not have to look at the health code,” one user from Sichuan wrote.
“Some people say the epidemic has only started now after three years of hard work. So was it a waste of time? What of all those who paid a huge price, and even their lives for it?”
Others worried for China’s elderly population, many of whom are still unvaccinated.
“Dr Li, the real test of the three-year epidemic has begun. The epidemic is not as serious as yours, but I am exhausted,” one person wrote.
Shown here is a pseudo-colored scanning electron micrograph of an oral squamous cancer cell (white) being attacked by two cytotoxic T cells (red), part of a natural immune response. Photo by National Cancer Institute on Unsplash
Researchers have demonstrated that the daily rhythms of the immune system – and in particular that of dendritic cells, its key sentinels – have a hitherto unsuspected impact on tumour growth. These results, published in Nature, indicate that simply changing the time of administration of a treatment could boost its effectiveness.
Like pathogens, cancer cells can be identified and targeted by a specific immune response, which can be enhanced by immunotherapy treatments.
In previous studies, the team from the University of Geneva (UNIGE) and the Ludwig-Maximilians University of Munich (LMU) had shown that the activation of the immune system is modulated according to the time of day, indicating a peak of efficiency early in the morning in humans.
The immune system is no exception to the circadian rhythm. ‘‘By studying the migration of dendritic cells in the lymphatic system, one of the most essential elements of the immune response, we had highlighted the fact that immune activation oscillates throughout the day, with a peak in the late behavioural resting phase,” summarises study leader Christoph Scheiermann, professor at the University of Geneva. In the current study, the group focussed on cancer to assess how this temporal modulation affected tumours.
Temporal profiling of dendritic cells
The scientists injected groups of mice with melanoma cells at six different times of the day and then monitored tumour growth for a fortnight. ‘‘By varying only the time of injection, we observed very surprising results: tumours implanted in the afternoon grew little, while those implanted at night grew much faster, in accordance with the rhythm of activation of the mice’s immune system’’, said Chen Wang, a researcher in Christoph Scheiermann’s lab and first author of this study. The research team then reproduced the experiment with mice that had no immune system. ‘‘There was no longer any difference related to the time of day, thus confirming that the latter is indeed induced by the immune response: the first immune cells activated are the dendritic cells of the skin, which are found 24 hours later in the lymph node. The T cells are then activated and attack the tumour.” Suppressing the internal clocks of the dendritic cells causes the rhythm of activation of the immune system to disappear, confirming their key role.
Lastly, the researchers administered an immunotherapy treatment at different times of the day to mice whose tumour implantation had taken place at the same time. ‘‘This therapeutic vaccine consisted of a tumour-specific antigen, very similar to what is used to treat patients. When administered in the afternoon, the beneficial effect was again increased.’’
Findings in humans
In order to find out whether these results were repeated in humans, the scientists re-examined the data of patients treated with cancer vaccines for melanoma. Melanoma-specific T cells in these patients responded better to treatments administered early in the morning, which corresponds to the human circadian profile, reversed in comparison with mice, which are nocturnal animals. ‘‘This is very encouraging, but it is only a retrospective study of a small cohort of ten people,’’ Christoph Scheiermann points out.
The researchers now want to confirm and refine these initial findings through clinical studies. However, the very idea that a treatment can become more potent depending on the time of day opens up some surprising possibilities.
Girls are routinely being given more generous grades than boys with the same academic competences, according to a new study of tens of thousands of Italian pupils and their teachers. This reflects other European studies reflecting higher teacher grading for girls.
This bias against boys could mean the difference between a pass and a fail in subjects such as maths. The researchers warn that it could also have wider consequences in areas such as university admission, job choice and earnings.
Their study, published in British Journal of Sociology of Education, is the first to demonstrate that the problem is systemic – it is present across a variety of educational environments, regardless of teachers’ characteristics.
Gender-related gaps in educational achievement are common worldwide. However, the nature of the gap differs with different ways of measuring achievement.
When the results of standardised tests, which have a standard scoring system, are used, girls typically outperform boys in humanities, languages and reading skills, while boys do better in maths.
In contrast, when grades are awarded by teachers, females do better than males in all subjects.
To find out how teachers’ evaluations tend to favour females, the University of Trento researchers began by comparing the scores students received in standardised tests of language and maths with the grades they achieved in their classroom exams.
The 38 957 students were around 15-16 years old. The standardised tests were set nationally and marked anonymously, while the classroom exams were set in the classroom and marked non-anonymously by their teachers.
In line with previous studies, the girls performed better than the boys in the standardised tests of language, while the boys were ahead at maths.
The teachers however, put the girls in front in both subjects. The girls’ average grade in language was 6.6 (out of 10), compared to 6.2 for the boys. In maths, the average grade for the girls was 6.3, while the boys averaged 5.9 – which is below the pass mark of 6.
The analysis also showed that when a boy and a girl were similarly competent at a subject, the girl would typically receive a higher grade.
The researchers then looked whether factors, such as the type of school and the size and gender make-up of classes, were driving the gender grade gap.
They also investigated whether characteristics of teachers themselves, such as how senior or experienced they were and whether they were male or female, helped explain girls’ more generous grades.
Only two factors were found to have an effect – and only in maths. The gender gap in maths grades was greater when classes were bigger. Girls were also graded as being further ahead than boys in technical and academic schools than they were in vocational schools.
None of the other factors had any significant effect in reducing the gender grading gap.
Taken overall, the results show for the first time that higher grading of girls is systemic – rather than stemming from one particular failing, it is embedded in the whole school system.
The study’s authors say it’s possible that, in reading, teachers unconsciously reward students exhibiting traditionally female behaviour, such as quietness and neatness, which make teaching easier for the teachers. Another theory is that inflated grades in mathematics are a way of trying to encourage girls, who are often seen as weaker in this subject.
The study’s authors conclude that bias against boys in Italian schools is considerable and could have long-term consequences.
“There is a strong correlation between having higher grades and desirable educational outcomes, such as gaining admission to good colleges or having a lower probability of dropping out of school,” says researcher Ilaria Lievore, a PhD candidate in Sociology.
“Consequently, higher grades are also correlated with other outcomes, such as having higher earnings, a better job or even higher life satisfaction.”
She adds that although other European countries also grade girls more generously than boys, the reasons for this could differ from place to place and won’t necessarily mirror those in Italy.
The study’s limitations include using grades which were awarded part-way through the school year, which may have differed from differed from the students’ final grades.
Canadian singer Celine Dion has revealed that she has been diagnosed with a very rare neurological disease called Stiff Person Syndrome (SPS), BBC News reports. The disease causes muscle spasms, interfering with daily activities. Injuries can be sustained from falls caused by spasms experienced while walking.
The 54-year-old singer had been battling with muscle spasms, and since the disease interferes with her singing, she has cancelled all of her concerts scheduled for 2023, putting them off to 2024.
SPS is an extremely rare disease, thought to affect only one in a million individuals. As such, relatively little is known about it and what causes it, although it is associated with autoimmune disorders and often misdiagnosed as Parkinson’s disease.
After a hiatus from 2014 to be with her husband while he battled cancer, she returned to the stage in 2019 with her new album Courage. This tour had a number of cancellations due to the COVID pandemic.
Speaking on an Instagram post, Dion said that she had “a great team of doctors working alongside me to help me get better” and had the support of her “precious children”.
The singer explained: “I’m working hard with my sports medicine therapist every day to build back my strength and my ability to perform again, but I have to admit it’s been a struggle.
“All I know is singing. It’s what I’ve done all my life and it’s what I love to do the most.
“I miss you so much. I miss seeing all of you [and] being on the stage, performing for you.
“I always give 100 per cent when I do my show but my condition is not allowing me to give you that right now.”
What is stiff person syndrome?
According to the National Institute for Neurological Disorders, SPS is characterised by “fluctuating muscle rigidity in the trunk and limbs and a heightened sensitivity to stimuli such as noise, touch, and emotional distress, which can set off muscle spasms. Abnormal postures, often hunched over and stiffened, are characteristic of the disorder. People with SPS can be too disabled to walk or move, or they are afraid to leave the house because street noises, such as the sound of a horn, can trigger spasms and falls. SPS affects twice as many women as men.”
A definitive diagnosis can be made by measuring the level of glutamic acid decarboxylase (GAD) antibodies in the blood, which is elevated in people with SPS. GAD is the rate-limiting enzyme that catalyses the conversion of glutamate to GABA
As for management, the symptoms can be well controlled. Pharmacological treatment includes IVIg, anti-anxiety drugs, muscle relaxants, anti-convulsants, and pain relievers.
Work continues for better treatments; so far rituximab proved ineffective. At present, research is focused on aetiology and the role of anti-GAD antibodies.
