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Saturday, February 17, 2024
3.176 AMICOR (26)
3.176 AMICOR (26)
#Com Dra. Valderês A. Robinson Achutti (*13/06/1931+15/06/2021)
Em Salvador (BA) a beira mar, em setembro de 2003, LVIII Congresso da SBC
#Re-Publicando o que escrevi há 1/4 de século em homenagem à Da. Luiza.
Texto que escrevi em 1999, quando o século XX acabava e nossa mãe morreu.
Cordão Umbilical
Aloyzio Achutti.
(Em memória de Luiza Cechella Achutti, uma homenagem a todas as mães do mundo)
*15/02/1911 +05/12/1999
Em tempos quando a genética parece tudo explicar e, quem sabe resolver, no caminho do genoma humano, quando um dos cromossomas já se encontra totalmente mapeado, e as maravilhas da engenharia genética já se acumulam a cada dia que passa, poderia parecer que o papel da mãe fosse o de uma simples estação de troca, num processo em que tudo já viesse predeterminado.
Não é bem assim. O pesquisador inglês David J. P. Barker (+) ensina ser o útero mais importante do que os genes, sugerindo que os destinos são traçados no caminho que vai do ventre ao colo materno.
Sabendo da enorme quantidade de genes disponíveis no momento da geração humana, a maior parte deles jamais utilizada, pode-se dizer que originalmente nossa chance de sermos todos muito mais parecidos é muito maior, e que a grande diferenciação se faz pela seleção materna, através das circunstâncias nas quais se vive durante o período em que dela se é dependente, de sua nutrição alimentar e afetiva.
A escolha dos recursos genéticos que devem ser ativados ou preservados depende dela, não através de um processo racional e consciente, mas de códigos modulados pelas suas circunstâncias, comportamento e afetividade. Assim se explicam não somente os dotes de cada um, mas também fragilidades e também propensões para doenças.
O pai, em geral entra como contribuinte direto somente na formação do banco genético original, mas depois só indiretamente, na medida de sua influência sobre a mãe.
As teorias satisfazem na medida em que servem para explicar os fenômenos observados, ou para revelar as etapas ocultas dos processos já em andamento, mas a preocupação agora não se restringe à etiopatogenia da artério-esclerose, da cardiopatia isquêmica, da hipertensão arterial ou da doença cérebro-vascular. Trata-se de pensar na mãe no caminho da despedida.
É como se enquanto presente, ela fosse a grande biblioteca na qual se pudesse a qualquer momento buscar nossas referências, mesmo não o fazendo. Agora queimada, só restam as cinzas da memória. Do período crítico no qual ela exerceu sua função de matriz não se pode ter consciência, mas encontram-se arquétipos e marcas bem definidas na cultura de todos os povos, respeitando a mãe, mesmo que não valorizando adequadamente a mulher.
Se a mãe está intimamente ligada à vida de cada indivíduo, está também necessariamente ligada à morte, por ser esta a estratégia básica de renovação e manutenção da vida da própria espécie. Quando ela morre fica bem claro que nossas referências pessoais são temporárias e estão definitivamente perdidas, garantindo a biodiversidade. O projeto da vida vai muito além dos limites da vida do indivíduo e só tem sentido quando integrado no grande projeto humano, de cujo início só restam mitos e o futuro se perde no curto horizonte da perspectiva.
É muito provável que ao perambular pelos frios corredores do mundo científico eu esteja evitando mostrar meu umbigo, sinal de uma ligação tão íntima, determinante de minha identidade e de meu caminho. Da ruptura do cordão umbelical restam apenas laços afetivos, além da cicatriz ridícula e que parece não ter sentido nenhum... *************************************** Quando minha irmã Lia (+) completou seus oitenta anos, em 2008, escrevi o texto seguinte lembrando a maternidade biológica e afetiva:
Mãe é imprescindível. Sem ela, com pequena contribuição paterna, não conseguimos existir, desenvolver, nascer, nos adaptarmos ao mundo e por fim viver independentemente.
Ao menos por enquanto é assim. Não sei se um dia não será possível o desenvolvimento em meio adequado, dentro de um tubo de ensaio, num laboratório. É possível que nem seja mais necessário um óvulo, e que possamos nascer por pura clonagem...
Mas não é este o enfoque que pretendo explorar neste momento. É o da figura materna, protetora, símbolo de carinho, fonte de afeto e nossa primeira referência.
Parece que a figura do pai serve para nos introduzir no conceito de limites e, por extensão, a descoberta de nossa identidade. Com ele aprendemos a nos reconhecer como indivíduos, independentes das circunstâncias e dos circunstantes.
Dona Luiza foi nossa mãe e com ela tivemos esta feliz experiência.
Se ter uma referência materna é tão bom, imaginem ter três ao mesmo tempo com idades diferentes... Já ouvi comentários sobre ser o último filhinho mimado da casa. Compreendo que possa haver uma pontinha de inveja nisso, mas é só para quem pode, não é para quem quer.
Lia Maria, que está completando os oitenta, com a Maria Helena, sempre foram a extensão e a continuidade da Dona Luiza. Em época de vacas magras até contribuíram para que eu pudesse seguir meus estudos em Porto Alegre.
Criei-me mal acostumado e procurei ter mais uma em casa, a Valderês, que me deu mais duas: a Ana e a Lucinha; e meu filho, a sétima que é a Julinha.
Meu pai também já se foi e nos ficamos em minoria: eu, meu filho, Pedro, Antônio e Eduardo, porém cercados de nossos amores.
Na Lia gostaria de sublimar toda esta relação de afeto que nos une.
Leading a healthy lifestyle, including regular exercise, eating fruits and vegetables, and minimal alcohol consumption, is associated with better cognitive function in older adults, new research showed.
The study, which combined longitudinal and cohort data with postmortem brain pathology reports, found that the association held even in those with Alzheimer's disease (AD) pathology, suggesting that lifestyle factors may provide cognitive reserve and improve cognitive abilities in older age.
"While we must use caution in interpreting our findings, in part due to its cross-sectional design, these results support the role of lifestyle in providing cognitive reserve to maintain cognitive function in older adults despite the accumulation of common dementia-related brain pathologies," Klodian Dhana, MD, of the Rush University Medical Center in Chicago, Illinois, and colleagues wrote.
Ancient viruses played a pivotal role in the development of myelin, crucial for complex vertebrate brains. The discovery of "RetroMyelin," a retrovirus-derived element essential for myelin production across mammals, amphibians, and fish, underscores the impact of viral genes on vertebrate evolution.
If you love math puzzles, you’ll love Hyperjumps, a daily arithmetic game from Quanta. We’re relaunching the game today with fun new features and simplified gameplay.
If evolution favors the survival of the fittest, where did the impulse to help others come from? Host Janna Levin speaks with Stephanie Preston, a neuropsychologist who studies the biology of altruism.
Each week Quanta Magazineexplains one of the most important ideas driving modern research. This week, our biology staff writer Yasemin Saplakoglu explores the mounting research on horizontal gene transfer.
What We Know About How DNA Jumps Between Species
By YASEMIN SAPLAKOGLU
If you have your father’s eyes or your grandmother’s freckles, you can thank the genes passed down within your family. But researchers have begun to recognize that at a deeper biological level, another type of genetic inheritance also occurs. Genes can cha-cha-slide between individuals — or even species — through a process known as horizontal gene transfer. It may be far from an everyday occurrence in complex organisms like humans, but on an evolutionary timescale, it may be happening far more often than anyone thought.
Horizontal gene transfers are relatively common in the bacterial world, where they play an important role in evolution and adaptation, and in the spread of antibiotic resistance. In fact, evolutionary biologists struggle to untangle some of the early branches of the tree of life because the high number of horizontal transfers among those ancient single-celled organisms intertwined lineages so thoroughly. Scientists also know very little about how this process might have significantly shaped the genomes of complex organisms like plants and animals.
For many years, scientists who argued that horizontal hops could be happening in multicellular species such as fish were given the side-eye by their peers. Such a migration requires a chain of unlikely events: A gene from one individual must somehow make it into the germline cells that produce the sperm or egg cells of an individual from another species. From there it must get into the nucleus and shimmy into the genome of its new host, who must then produce offspring with those eggs or sperm to pass down that modified genome. Important drivers of this process are often the genetic elements called transposons, or “jumping genes,” which can copy and paste themselves to different positions in a genome, or even from one genome to another. Sometimes they seem to do that by catching a ride into a new host’s body inside a parasite or virus. It’s a journey with a lot of unlikely steps, but molecular biology suggests it happens.
Studies have pinpointed cases of horizontal transfers in a diverse array of animals, including fish, frogs and snakes. Still, it’s unclear to what extent complex eukaryotic organisms share genes with other life in this way. The data so far suggests that it’s more likely for genes to hop from bacteria into eukaryotes than the other way around: Experiments show that when eukaryotic genes trespass into bacteria, the bacteria often eject them.
Biologists have made many surprising discoveries in recent years about the movement of genes between species.
What’s New and Noteworthy
In 2022, researchers reported that a gene called BovB has moved from snakes to frogs independently at least 50 times in various parts of the planet. Oddly, they found that it has happened much more often in Madagascar than elsewhere. It’s not clear why. One factor could be the high number of parasites such as leeches that live on the island and move from host to host, carrying acquired sequences of DNA in the blood they’ve drunk. Evidence of ancient horizontal gene transfers is often scrambled by time, but researchers are now hoping to catch transfers in the act by looking at organisms in hot springs in Yellowstone National Park.
Horizontal gene transfer also seems to have figured in how marine life around the poles evolved — or rather, borrowed — defenses to survive the freezing cold. Researchers found that herrings and smelts, two groups of fish that diverged more than 250 million years ago, use the same gene to make proteins that stop ice crystals from growing in their body. It took decades to convince researchers that the gene must have hopped from the herring to the smelt. How much this kind of horizontal transfer happens among vertebrate cells is unclear, but one study found evidence of at least 975 transfers among 307 vertebrate genomes, mainly in ray-finned fishes.
Gene transfers between species are even relevant to humans, or more specifically to our microbiomes, the sturdy armies of microorganisms that occupy our gut and other parts of the body. A human baby’s microbiome first comes from their mother. But surprisingly, those maternal gifts aren’t always whole cells. Small snippets of DNA from a mother’s bacteria can hop to the baby’s bacteria through horizontal gene transfers even months after birth. These genes, which often come from helpful bacterial strains in the mother, could play an important role in the baby’s growth and development. Though it’s not clear whether the horizontal gene transfers directly benefit the baby by conveying particular functions, they might be indirectly useful by assembling a more capable gut microbiome.
AROUND THE WEB
Popular Mechanics described a particularly eerie example of horizontal gene transfer. By stealing genes, parasites known as horsehair worms gained the ability to control the minds of their insect hosts.
Trends in Plant Science published a paper that describes how horizontal gene transfer may have shaped the evolution of land plants.
Trends in Genetics published an opinion piece by two scientists speculating about how common horizontal gene transfer might be among complex organisms.
Neural Academy on YouTube did a deep dive into the topic in a video about the mechanisms of horizontal gene transfer, using fun illustrations to describe the three ways that bacteria can horizontally acquire new genes.
In China in 1981, 97% of people in the countryside lived in extreme poverty.
By 2020, the share was well below 1%.
Large economic growth made it possible for hundreds of millions of people to leave extreme poverty behind, first in cities and then in the countryside.
Extreme poverty is defined as living below the World Bank’s International Poverty Line of $2.15 per day. This is adjusted for both inflation and cost of living differences between countries — it’s the equivalent of what $2.15 could buy you in the United States.
Nine countries currently have nuclear weapons: Russia, the United States, China, France, the United Kingdom, Pakistan, India, Israel, and North Korea.
These nuclear powers differ a lot in how many nuclear warheads they have. The chart shows that while most have dozens or a few hundred warheads, Russia and the United States have thousands of them.
The chart also shows that the warheads differ in how — and how quickly — they can be used: some are designed for strategic use, meaning use away from the battlefield, such as against arms industries or infrastructure. Others are designed for nonstrategic, tactical use on the battlefield.
A substantial share of them are deployed on ballistic missiles or bomber bases and can be used quickly. Some warheads are not deployed, or are even retired and queued for dismantlement.
This month, tobacco control advocates gathered for the 10th Conference of the Parties to the WHO Framework Convention on Tobacco Control (COP10) in Panama. /.../
Smoking cigarettes scars the body’s immune system for years after quitting. Researchers investigated 1,000 people’s immune responses by exposing their blood samples to various challenges, such as bacteria. In active smokers, both general and specific immune response was affected. But even in people who stopped years ago, an effect on crucial T cells seemed to linger. “Having higher T cell responses is seen in many autoimmune diseases”, such as rheumatoid arthritis explains immunologist and study co-author Darragh Duffy. “There's still a lot to uncover.”
Summary: Researchers have made a groundbreaking discovery, identifying a rare lipid as a crucial factor in
ferroptosis, a unique form of cell death. This lipid, characterized by its two polyunsaturated fatty acyl tails, plays a significant role in various conditions, including neurodegenerative diseases and cancer. The findings could revolutionize our approach to treating these diseases by either preventing or inducing ferroptosis. Key Facts: Discovery of diPUFA Lipids: A rare lipid with two polyunsaturated fatty acyl tails, known as diPUFA phospholipid, has been found to significantly promote ferroptosis in cells, including those in aging brains and Huntington disease-affected brain tissue. Potential for Disease Treatment: Understanding the role of diPUFA lipids in ferroptosis opens new avenues for treating neurodegenerative diseases and cancer, by either preventing or inducing cell death. Interdisciplinary Research: The research was a collaborative effort by Columbia’s Department of Biological Sciences, Department of Chemistry, and the Columbia University Irving Medical Center, highlighting the interdisciplinary approach to uncovering the mechanisms of ferroptosis. Source: Columbia University Columbia researchers have found that a rare type of lipid is a key driver of ferroptosis, a form of cell death discovered by Columbia professor Brent Stockwell. The findings provide new detail on how cells die during ferroptosis and could improve understanding of how to stop ferroptosis in contexts where it is harmfully occurring– in neurodegenerative diseases, for example– or induce it in contexts where it could be useful, such as using it to kill dangerous cancer cells.
Together, these papers show that specific lipids promote ferroptosis, so defining the driver lipids in specific cancers is important. Credit: Neuroscience News
The new research found that a rare type of lipid with two polyunsaturated fatty acyl tails, called a diPUFA phospholipid, was present in a range of contexts where ferroptosis was occurring, including in aging brains and Huntington disease-affected brain tissue. The finding indicates that the lipid is efficient at promoting ferroptosis. The research was conducted by professors in Columbia’s Department of Biological Sciences, Department of Chemistry, and the Columbia University Irving Medical Center. Stockwell first discovered ferroptosis in 2012, when he found that certain cells were dying because their lipid layers were collapsing– an unusual form of cell death that differs from the most common kind, which begins with
the cell forming blisters on its outer surface. Since that discovery, researchers in Stockwell’s lab and elsewhere have continued to investigate ferroptosis, discovering that it can occur naturally in aging cells, in pathological contexts, and can be induced to treat disease. Another paper out this month with several co-authors found that a gene named PHLDA2 can sometimes promote ferroptosis by attacking a different lipid, and that this gene can block some tumors from forming. Together, these papers show that specific lipids promote ferroptosis, so defining the driver lipids in specific cancers is important. “The discovery that these diPUFA lipids are important drivers of ferroptosis deepens our understanding of this form of cell death, and these lipids’ role in controlling a cell’s homeostasis in general,” Stockwell said. “Harnessing these lipids may eventually help us identify where ferroptosis has occurred and deliberately manipulate
them to either induce cell death or stop it. This can begin to give us both understanding and the power to control cell death.”
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