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Archive for the ‘biotech/medical’ category: Page 1154

Sep 15, 2021

Saliva test for COVID-19 outperforms commercial swab tests

Posted by in categories: biotech/medical, surveillance

In the early days of the pandemic, with commercial COVID tests in short supply, Rockefeller University’s Robert B. Darnell developed an in-house assay to identify positive cases within the Rockefeller community. It turned out to be easier and safer to administer than the tests available at the time, and it has been used tens of thousands of times over the past nine months to identify and isolate infected individuals working on the university’s campus.

Now, a new study in PLOS ONE confirms that Darnell’s test performs as well, if not better, than FDA-authorized nasal and oral swab tests. In a direct head-to-head comparison of 162 individuals who received both Rockefeller’s “DRUL” test and a conventional swab test, DRUL caught all of the cases that the swabs identified as positive—plus four positive cases that the swabs missed entirely.

“This research confirms that the test we developed is sensitive and safe,” says Darnell, the Robert and Harriet Heilbrunn professor and head of the Laboratory of Molecular Neuro-Oncology. “It is inexpensive, has provided excellent surveillance within the Rockefeller community, and has the potential to improve safety in communities as the pandemic drags on.”

Sep 15, 2021

COVID Virus May Prompt Body to Attack Itself

Posted by in category: biotech/medical

Jan. 29 2021 — An international team of researchers studying COVID-19 has made a startling and pivotal discovery: The virus appears to cause the body to make weapons to attack its own tissues.

The finding could unlock a number of COVID’s clinical mysteries. They include the puzzling collection of symptoms that can come with the infection; the persistence of symptoms in some people for months after they clear the virus, a phenomenon dubbed long COVID; and why some children and adults have a serious inflammatory syndrome, called MIS-C or MIS-A, after their infections.

“It suggests that the virus might be directly causing autoimmunity, which would be fascinating,” says lead study author Paul Utz, MD, who studies immunology and autoimmunity at Stanford University in Stanford, CA.

Sep 15, 2021

COVID-19 nasal vaccine candidate

Posted by in categories: biotech/medical, chemistry, engineering

September 15 2021 — Breathe in, breathe out. That’s how easy it is for SARS-CoV-2, the virus that causes COVID-19, to enter your nose. And though remarkable progress has been made in developing intramuscular vaccines against SARS-CoV-2 such as the readily available Pfizer, Moderna and Johnson & Johnson vaccines, nothing yet – like a nasal vaccine – has been approved to provide mucosal immunity in the nose, the first barrier against the virus before it travels down to the lungs.

But now, we’re one step closer.

Navin Varadarajan, University of Houston M.D. Anderson Professor of Chemical and Biomolecular Engineering, and his colleagues, are reporting in iScience the development of an intranasal subunit vaccine that provides durable local immunity against inhaled pathogens.

Sep 15, 2021

An observational and Mendelian randomisation study on vitamin D and COVID-19 risk in UK Biobank

Posted by in categories: biotech/medical, energy, genetics

The discriminatory power of the UVB variable is somewhat limited in this study, because UVB radiation is low at this time of the year, particularly at the high northern latitude of UK—larger effects might be observed if variation in UVB is greater. We only used ambient UVB, and did not capture individual behavioural differences that would determine the actual level of vitamin D synthesis in the skin, such as duration and time of day spent outside, clothing, etc. It is important to note that time of year is the strongest predictor of vitD-UVB. To avoid bias control dates were assigned to follow the same distribution as case dates, which might have led to artificially diminished differences in vitD-UVB between cases and controls, however analysis relating to hospitalisation and death are not affected by this. We also conducted an analysis of the genetically-predicted vitamin D and a number of state-of-the-art MR analyses. However, the main limitation is the lack of power. Given the small number of COVID-19 patients and the relatively small percentage of variance (4.2%) explained by vitamin D-related genetic variants, this MR study was not adequately powered to detect small causal effect and negative results should be interpreted with caution. Additionally, MR studies only consider linear effects between 25-OHD levels and COVID-19 risk, which do not capture what happens at the extremes of vitamin D deficiency. Therefore, it cannot rule out the possibility that seriously ill patients (due to an underlying pathology) with extremely low vitamin D levels could be predisposed to COVID-19 infection and increased COVID-19 severity and mortality. Furthermore, 25-OHD levels are the used biomarker of vitamin D status in the study population, nevertheless, they correlate poorly with the active form of vitamin D (1,25-OH2D), which exerts the effects of vitamin D on a cellular level. Thus, this study cannot exclude effects of 1,25-OH2D on COVID-19 risk.

Another limitation of this cohort relates to the fact that not all participants have been tested for present (or past) COVID-19 infection; consequentially, taking participants who were not tested as controls could be a potential source of bias, given that misclassification of controls might be substantial due to the presence of asymptomatic infected individuals, further driving our findings to the null. This is evident from the 1:2 ratio between outpatient vs. inpatient cases. It should be acknowledged that the COVID-19 cases in UK biobank have a high rate of hospitalisation due to the very limited and targeted testing at this stage of the pandemic in the UK, so this study reflects mainly those with more severe COVID-19 and gives less information about true infection risk, or risk of milder disease. In addition, we excluded individuals with a negative COVID-19 testing result from the controls due to the risk of those being false negatives. Although there is a risk of introducing selection bias, we believe that the risk of introducing misclassification bias if we included them in the analysis could be higher22,23. Additionally, given the presence of asymptomatic infected individuals, taking participants who were not tested as controls could also be another potential source of bias. Our study assessed the effect of genetically predicted vitamin D levels on COVID-19 risk while taking into consideration of ambient UVB radiation during the pandemic. We show an indication of an inverse association between genetically predicted vitamin D levels and severe COVID-19. Findings from our study are consistent with a recent randomised controlled trial (RCT) that found protective effect of vitamin D supplementation among those hospitalised with COVID-1924. However, other clinical trials did not show an effect. For instance, a randomised trial of 240 patients showed that supplementation with a single very large dose of 200,000 IU of vitamin D3 that increased serum vitamin D levels (21–44 ng/ml) was nonetheless ineffective in decreasing the length of hospital stay or any other clinical outcomes among hospitalized patients with severe COVID-1925. It has been estimated that one SD change in standardized natural-log transformed 25-OHD levels corresponds to a change in 25-OHD levels of 29.2 nmol/l in vitamin D insufficient individuals (serum 25-OHD levels 50 nmol/l), which is comparable to the 21.2 nmol/l mean increase in 25-OHD levels conferred by taking daily 400 IU of cholecalciferol, the amount of vitamin D most often found in vitamin D supplements26. This estimation has clinical implication on the dose of vitamin D supplement for disease prevention. Given the lack of highly effective therapies against COVID-19, it is important to remain open-minded to emerging results from rigorously conducted studies of vitamin D.

In conclusion, we found no significant associations between COVID-19 risk and measured 25-OHD levels after adjusted for covariates, but this finding is limited by the fact that the vitamin D levels were measured on average 11 years before the pandemic. Ambient UVB was strongly and inversely associated with COVID-19 hospitalization and death. The main MR analysis did not show that genetically-predicted vitamin D levels were causally associated with COVID-19 risk, although MR sensitivity analyses indicated a potential causal effect. Overall, the effect of vitamin D levels on the risk or severity of COVID-19 remains controversial, further studies are needed to validate vitamin D supplementation as a means of protecting against worsened COVID-19.

Sep 15, 2021

Homemade face masks work; effectiveness varies depending on how they are made

Posted by in category: biotech/medical

Since the spread of virus causing COVID-19 continues, experts recommended wearing homemade facemasks when surgical or N95 masks are not available to prevent the spread of the pandemic. While such makeshift masks are more economical and accessible in low-capita countries, the effectiveness of cloth masks has not been studied in depth.

In Physics of Fluids, researchers from the Indian Institute of Science studied the fate of a large-sized surrogate cough droplets at different velocities, corresponding from mild to severe, while using various locally procured fabrics as masks.

“Our results show cotton, towel-based fabrics were most effective among the considered fabrics and must be stitched together as multiple layers for making homemade facemasks,” said author Saptarshi Basu. “A three or more-layered homemade mask is recommended, since it can suppress aerosolization significantly.”

Sep 15, 2021

Identification of resident memory CD8+ T cells with functional specificity for SARS-CoV-2 in unexposed oropharyngeal lymphoid tissue

Posted by in category: biotech/medical

A Science Immunology analysis of patient samples collected before the #COVID19 pandemic shows that killer #Tcells that can recognize #SARSCoV2, despite never having encountered the virus before, are located in tissues, rather than circulating in blood.


Tissue-resident memory CD8+ T cells in unexposed oropharyngeal lymphoid tissue exhibit specificity for SARS-CoV-2.

Sep 15, 2021

Biotech Firm Raises $15 Million to Bring Woolly Mammoth Back to Life

Posted by in categories: biotech/medical, existential risks

After 10,000 years of extinction, one company wants to bring the woolly mammoth back to life.


The biotech firm Colossal raised $15 million in a bid to revive the extinct woolly mammoth by manipulating the DNA of Asian elephants.

Sep 15, 2021

The Hunt for Drugs That Promote Ear Hair Cell Regeneration

Posted by in category: biotech/medical

A research team from Nanjing University has used cochlear organoids to identify drugs that can promote the regeneration of hair cells. The study, published in Stem Cell Reports, also identifies a signaling pathway as a potential target for hearing restoration.

Hearing is a complex multistep process that allows us to detect sound and involves three key parts of the ear – the outer, middle and inner ear. Sound waves are collected by the pinna of the outer ear and are funneled into the ear canal until they meet the ear drum (tympanic membrane), causing it to vibrate.

The resulting vibrations are transmitted to the ossicles – comprising a chain of three small bones called malleus, incus and stape – located within the middle ear. Movement of the bones transmits the sound vibrations to the inner ear, sending a signal to the cochlea (a hollow spiraling structure filled with fluid). Vibrations cause the fluid within the cochlea to ripple, forming waves that stimulate the movement of hair cells positioned on the top of the basilar membrane that separates the two fluid-filled chambers running along the cochlea.

Sep 14, 2021

Scientists Say They Could Bring Back Woolly Mammoths. But Maybe They Shouldn’t

Posted by in categories: bioengineering, biotech/medical, genetics

A company formed by Harvard genetics professor George Church, known for his pioneering work in genome sequencing and gene splicing, hopes to genetically resurrect woolly mammoths.

Sep 14, 2021

The tangled history of mRNA vaccines

Posted by in categories: biotech/medical, innovation

The story illuminates the way that many scientific discoveries become life-changing innovations: with decades of dead ends, rejections and battles over potential profits, but also generosity, curiosity and dogged persistence against scepticism and doubt. “It’s a long series of steps,” says Paul Krieg, a developmental biologist at the University of Arizona in Tucson, who made his own contribution in the mid-1980s, “and you never know what’s going to be useful”.


Hundreds of scientists had worked on mRNA vaccines for decades before the coronavirus pandemic brought a breakthrough.