Comment

Comment by Dr. Krishna Kumari Challa on June 28, 2022 at 9:46am

Oceans saved us, now we can return the favour

Humanity must heal oceans made sick by climate change, pollution and overfishing in order to rescue marine life and save ourselves, experts warned ahead of a major UN conference.

By absorbing—decade after decade—a quarter of CO2 pollution and more than 90 percent of excess heat from global warming, oceans have kept Earth's terrestrial surface liveable.

Our species has returned the favor by dumping mountains of plastic waste into the sea, emptying the deep blue of big fish, and poisoning coastlines with toxic chemicals and agricultural runoff that create dead zones bereft of oxygen.

"If we don't do the right things now, we might end up with a dead oceans”

Comment by Dr. Krishna Kumari Challa on June 28, 2022 at 8:59am

The newly discovered viruses that infect currently living Asgard archaea do have some features similar to viruses that infect eukaryotes, including the ability to copy their own DNA and hijack protein modification systems of their hosts. The fact that these recovered Asgard viruses display characteristics of both viruses that infect eukaryotes and prokaryotes, which have cells without a nucleus, makes them unique since they are not exactly like those that infect other archaea or complex life forms.

The most exciting thing is they are completely new types of viruses that are different from those that we've seen before in archaea and eukaryotes, infecting our microbial relatives.

The Asgard archaea, which probably evolved more than 2 billion years ago and whose descendents are still living, have been discovered in deep sea sediments and hot springs around the world, but so far only one strain has been successfully grown in the lab. To identify them, scientists collect their genetic material from the environment and then piece together their genomes. In this latest study, the researchers scanned the Asgard genomes for repeating DNA regions known as CRISPR arrays, which contain small pieces of viral DNA that can be precisely matched to viruses that previously infected these microbes. These genetic "fingerprints" allowed them to identify these stealthy viral invaders that infect organisms with key roles in the complex origin story of eukaryotes.

We are now starting to understand the implication and role that viruses could have had in the eukaryogenesis puzzle.

Brett Baker, Genomes of six viruses that infect Asgard archaea from deep-sea sediments, Nature Microbiology (2022). DOI: 10.1038/s41564-022-01150-8. www.nature.com/articles/s41564-022-01150-8

Part 2

**

Comment by Dr. Krishna Kumari Challa on June 28, 2022 at 8:57am

Virus discovery offers clues about origins of complex life

The first discovery of viruses infecting a group of microbes that may include the ancestors of all complex life has been found, researchers report in Nature Microbiology. The discovery offers tantalizing clues about the origins of complex life and suggests new directions for exploring the hypothesis that viruses were essential to the evolution of humans and other complex life forms.

There is a well-supported hypothesis that all complex life forms such as humans, starfish and trees—which feature cells with a nucleus and are called eukaryotes—originated when archaea and bacteria merged to form a hybrid organism. Recent research suggests the first eukaryotes are direct descendants of so-called A.... The latest research sheds light on how viruses, too, might have played a role in this billions-year-old history.

This study is opening a door to better resolving the origin of eukaryotes and understanding the role of viruses in the ecology and evolution of Asgard archaea. There is a hypothesis that viruses may have contributed to the emergence of complex cellular life.

There is a hypothesis called viral eukaryogenesis. It suggests that, in addition to bacteria and archaea, viruses might have contributed some genetic component to the development of eukaryotes. This latest discovery does not settle that debate, but it does offer some interesting clues.

Part1

Comment by Dr. Krishna Kumari Challa on June 28, 2022 at 8:32am

Monkeypox found to be evolving at a faster rate than expected

A team of researchers  has found that the monkeypox virus has been evolving at a faster rate than expected. In their paper published in the journal Nature Medicine, the researchers describe their genetic study of the virus collected from 15 samples

Monkeypox is a double-stranded DNA virus from the same genus as smallpox, and it mostly infects people in Africa. Scientist have known of its existence since the 1950s. Despite its name, the virus is more commonly found in rodents than monkeys. Prior research has shown that there are two main varieties of monkeypox: West African and Congo Basin—the former is far less deadly and is the clade that has infected several thousand people outside Africa. Prior research has also shown that viruses like monkeypox typically only mutate once or twice in a given year.

In this new effort, the researchers collected samples from 15 patients and subjected them to genetic analysis to learn more about how quickly the virus is evolving. They found the virus has mutated at a rate six to 12 times as high as was expected. The researchers suggest the sudden accelerated rate of mutation in the virus may be a sign that the virus has developed a new way to infect people—currently, it is believed to move from person to person through close contact with open lesions, through body fluids or by airborne droplets.

Joana Isidro et al, Phylogenomic characterization and signs of microevolution in the 2022 multi-country outbreak of monkeypox virus, Nature Medicine (2022). DOI: 10.1038/s41591-022-01907-y

In studying the mutations, the researchers found signs suggesting that some of the mutations may have been due to exposure to the human immune system, most particularly enzymes of a type called APOBEC3—they kill viruses by inciting mistakes during copying of genetic code. If some of the viruses survived such an attack and passed on their genes, they would have given future generations a leg up against the human immune system. And that could explain why the virus has been mutating more rapidly than expected. The researchers also note that the virus may have been circulating at low levels in human communities or spreading among animals in other countries. They also note that the accelerated rate of evolution could be a response to the crackdown that ensued during the monkeypox outbreak in 2017.

**

Comment by Dr. Krishna Kumari Challa on June 27, 2022 at 9:47am

Octopus brain and human brain share the same 'jumping genes'

The octopus is an exceptional organism with an extremely complex brain and cognitive abilities that are unique among invertebrates. So much so that in some ways it has more in common with vertebrates than with invertebrates. The neural and cognitive complexity of these animals could originate from a molecular analogy with the human brain, as discovered by a research paper recently published in BMC Biology.

The research shows that the same "jumping genes" are active both in the human brain and in the brain of two species, Octopus vulgaris, the common octopus, and Octopus bimaculoides, the Californian octopus. This discovery could help us understand the secret of the intelligence of these fascinating organisms.

Sequencing the human genome revealed as early as 2001 that over 45% of it is composed of sequences called transposons, so-called "jumping genes" that, through molecular copy-and-paste or cut-and-paste mechanisms, can "move" from one point to another of an individual's genome, shuffling or duplicating. In most cases, these mobile elements remain silent: they have no visible effects and have lost their ability to move. Some are inactive because they have, over generations, accumulated mutations; others are intact, but blocked by cellular defense mechanisms. From an evolutionary point of view, even these fragments and broken copies of transposons can still be useful, as "raw matter" that evolution can sculpt.

Among these mobile elements, the most relevant are those belonging to the so-called LINE (Long Interspersed Nuclear Elements) family, found in a hundred copies in the human genome and still potentially active. It has been traditionally thought that LINEs' activity was just a vestige of the past, a remnant of the evolutionary processes that involved these mobile elements, but in recent years new evidence emerged showing that their activity is finely regulated in the brain. There are many scientists who believe that LINE transposons are associated with cognitive abilities such as learning and memory: they are particularly active in the hippocampus, the most important structure of our brain for the neural control of learning processes.

The octopus' genome, like ours, is rich in "jumping genes," most of which are inactive. Focusing on the transposons still capable of copy-and-paste, the researchers identified an element of the LINE family in parts of the brain crucial for the cognitive abilities of these animals. The discovery  was made possible thanks to next generation sequencing techniques, which were used to analyze the molecular composition of the genes active in the nervous system of the octopus.

The discovery of an element of the LINE family, active in the brain of the two octopuses species, is very significant because it adds support to the idea that these elements have a specific function that goes beyond copy-and-paste.

The brain of the octopus is functionally analogous in many of its characteristics to that of mammals. For this reason, also, the identified LINE element represents a very interesting candidate to study to improve our knowledge on the evolution of intelligence.

“Identification of LINE retrotransposons and long non-coding RNAs expressed in the octopus brain” by Giuseppe Petrosino, Giovanna Ponte, Massimiliano Volpe, Ilaria Zarrella, Federico Ansaloni, Concetta Langella, Giulia Di Cristina, Sara Finaurini, Monia T. Russo, Swaraj Basu, Francesco Musacchia, Filomena Ristoratore, Dinko Pavlinic, Vladimir Benes, Maria I. Ferrante, Caroline Albertin, Oleg Simakov, Stefano Gustincich, Graziano Fiorito and Remo Sanges, 18 May 2022, BMC Biology.
DOI: 10.1186/s12915-022-01303-5

Comment by Dr. Krishna Kumari Challa on June 25, 2022 at 8:44am

Environmental factors predict risk of death: study

Along with high blood pressure, diabetes, and smoking, environmental factors such as air pollution are highly predictive of people's chances of dying, especially from heart attack and stroke, a new study shows.

the study showed that exposure to above average levels of outdoor air pollution increased risk of death by 20%, and risk of death from cardiovascular disease by 17%.

Using wood- or kerosene-burning stoves, not properly ventilated through a chimney, to cook food or heat the home also increasd overall risk of death (by 23% and 9%) and cardiovascular death risk (by 36% and 19%). Living far from specialty medical clinics and near busy roads also increased risk of death.

Publishing in the journal PLOS ONE online June 24, the findings come from personal and environmental health data collected from 50,045 mostly poor, rural villagers living in the northeast Golestan region of Iran. All study participants were over age 40 and agreed to have their health monitored during annual visits with researchers dating as far back as 2004.

Researchers say their latest investigation not only identifies environmental factors that pose the greatest risk to heart and overall health, but also adds much-needed scientific evidence from people in low- and middle -income countries

Spatial environmental factors predict cardiovascular and all-cause mortality: Results of the SPACE Study, PLoS ONE (2022).

https://medicalxpress.com/news/2022-06-environmental-factors-death....

Comment by Dr. Krishna Kumari Challa on June 24, 2022 at 9:06am

Breast cancer spreads at night

A new study shows that breast cancer metastases form more efficiently while patients are sleeping. This finding could significantly change the way cancer is diagnosed and treated in future.

Breast cancer is one of the most common forms of cancer, according to the World Health Organization (WHO). Each year, around 2.3 million people worldwide contract the disease. If doctors detect breast cancer early enough, patients usually respond well to treatment. However, things become much more difficult if the cancer has already metastasised. Metastasis occurs when circulating cancer cells break away from the original tumour, travel through the body via blood vessels and form new tumours in other organs.

To date, cancer research has not paid much attention to the question of when tumours shed metastatic cells. Researchers previously assumed that tumours release such cells continuously. However, a new study by researchers at ETH Zurich, the University Hospital Basel and the University of Basel has now come to a surprising conclusion: circulating cancer cells that later form metastases mainly arise during the sleep phase of the affected individuals. The results of the study have just been published in the journal Nature.

Circadian rhythm-​regulated hormones control metastasis
When the affected person is asleep, the tumour awakens!

 The researchers found that the tumour generates more circulating cells when the organism is asleep. Cells that leave the tumour at night also divide more quickly and therefore have a higher potential to form metastases, compared to circulating cells that leave the tumour during the day.

This research shows that the escape of circulating cancer cells from the original tumour is controlled by hormones such as melatonin, which determine our rhythms of day and night.

The study indicates that the time in which tumour or blood samples are taken for diagnosis may influence the findings of oncologists. It was an accidental finding along these lines that first put the researchers on the right track. Some scientists work early in the morning or late in the evening; sometimes they’ll also analyse blood at unusual hours. The scientists were surprised to find that samples taken at different times of the day had very different levels of circulating cancer cells.

Another clue was the surprisingly high number of cancer cells found per unit of blood in mice compared to humans. The reason was that as nocturnal animals, mice sleep during the day, which is when scientists collect most of their samples.
These findings may indicate the need for healthcare professionals to systematically record the time at which they perform biopsies. 

The researchers’ next step will be to figure out how these findings can be incorporated into existing cancer treatments to optimise therapies. 

Zoi Diamantopoulou, Francesc Castro-Giner, Fabienne Dominique Schwab, Christiane Foerster, Massimo Saini, Selina Budinjas, Karin Strittmatter, Ilona Krol, Bettina Seifert, Viola Heinzelmann-Schwarz, Christian Kurzeder, Christoph Rochlitz, Marcus Vetter, Walter Paul Weber, Nicola Aceto. The metastatic spread of breast cancer accelerates during sleep. Nature, 2022; DOI: 10.1038/s41586-022-04875-y

Comment by Dr. Krishna Kumari Challa on June 24, 2022 at 8:26am

Wearable antimicrobial copper nanomesh sticks to human skin, killin...

A team of researchers from the University of Tokyo, the Korea Research Institute of Bioscience and Biotechnology and the Center for Emergent Matter Science & Thin-Film Device Laboratory RIKEN 2-1 Hirosawa has developed a wearable antimicrobial nanomesh material that sticks to human skin, killing microbes nearly instantly. They have published their creation in Proceedings of the National Academy of Sciences.

--

Diagnosing jaundice using tear fluids

Human tear fluids contain many proteins, metabolites, and other molecules whose concentrations change significantly with certain diseases. A research team has now developed a handy test kit for tears that can identify patients with jaundice. Their success is based on a hybrid sensor that simultaneously removes impurities from the sample. This approach could provide new methods for early detection and diagnosis based on complex bodily fluids, as the team reported in the journal Angewandte Chemie International Edition.

--

How the first biomolecules could have been formed

The chemical precursors of present-day biomolecules could have formed not only in the deep sea at hydrothermal vents, but also in warm ponds on the Earth's surface. The chemical reactions that may have occurred in this "primordial soup" have now been reproduced in experiments by an international team led by researchers of Friedrich Schiller University Jena, Germany. They even found that one of the nucleobases, which represent the code of our genetic material, could have originated from the surface of our planet

----

A newly identified stem cell regulator enables lifelong sperm produ...

Unlike women, who are born with all the eggs they'll ever have, men can continue to produce sperm throughout their adult lives. To do so, they require a constant renewal of spermatogonial stem cells, which give rise to sperm.

Comment by Dr. Krishna Kumari Challa on June 24, 2022 at 7:21am

World's biggest giant bacteria that can be seen without a microscope

These thin vermicelli-like threads are revealed to be single bacterial cells!

The unusual size is notable because bacteria aren't usually visible without the assistance of microscope. It's 5,000 times bigger than most bacteria

For most bacteria, their DNA floats freely within the cytoplasm of their cells. This newly discovered species of bacteria keeps its DNA more organized. "The big surprise of the project was to realize that these genome copies that are spread throughout the whole cell are actually contained within a structure that has a membrane. "And this is very unexpected for a bacterium."

 It is a bacterium belonging to the genus Thiomargarita,. Scientists named it Ca. Thiomargarita magnifica.

 This is a  sulfur-oxidizing, carbon fixing bacterium and are important in mangrove eco systems . They contain membrane-bound compartments that contain DNA clusters . Scientists  dubbed these organelles "pepins," The bacteria contain three times more genes than most bacteria and hundreds of thousands of genome copies (polyploidy) that are spread throughout the entire cell.

In terms of metabolism, it does chemosynthesis, which is a process analogous to photosynthesis for plants.

Jean-Marie Volland et al, A centimeter-long bacterium with DNA contained in metabolically active membrane-bound organelles, Science (2022). DOI: 10.1126/science.abb3634. www.science.org/doi/10.1126/science.abb3634

Comment by Dr. Krishna Kumari Challa on June 21, 2022 at 9:07am

Scientists transplant human photoreceptors to successfully recover daylight perception in mice

Transplantation of photoreceptor cells is a promising intervention that in the future could help recover vision in people with blinding diseases. A team of researchers developed a robust method to produce high numbers of human photoreceptor cells. The researchers show that such human photoreceptors can incorporate in bulk into partially degenerated mouse retinas. The incorporated photoreceptors developed characteristics of normal photoreceptors and allowed mice with damaged eyesight to detect daylight.

The new study represents a step forward in an effort to bring photoreceptor transplantations to patients with blinding diseases.

To massively increase the number of incorporated photoreceptors, the scientists optimized multiple critical factors. They established that the age of transplanted photoreceptors is decisive.

The team also found that the integration into the retina needs a longer time. 

The interaction with the remaining, undamaged cells in the mouse retina turned out to be a key factor. About 30% of the cells in the retina are other cells that support the work of photoreceptors. In this case, researchers clearly saw that the interaction of transplanted cells with host retinal cells was crucial for successful incorporation and maturation. Some of these remaining cells provided a scaffold for the new photoreceptors and helped them organize correctly.

To produce photoreceptors, the team used stem cells to grow mini-retinas in a laboratory dish.

Obtaining a pure population of photoreceptors is yet another challenge. To address it researchers developed a new stem cell line in which cone photoreceptor cells have special tags. These tags do not interfere with their function but allow us to robustly sort photoreceptors from the rest of the cells in the mini-retinas.

Such induced pluripotent stem cell lines provide a virtually unlimited source of photoreceptors and can potentially be used in future clinical applications.

In this study, the team focused on mice with partially degenerated retinas that lacked only one out of two types of photoreceptors. The mice had only damaged cones, which are responsible for daylight vision, a situation similar to several blinding diseases in human patients. 

https://www.jci.org/articles/view/154619

• ‹ Previous
• 1
• …
• 477
• 478
• 479
• 480
• 481
• …
• 1072
• Next ›
• Page