Latest news with #PVN
The Hindu
05-07-2025
- Health
- The Hindu
Kerala to launch antibody surveillance studies on Nipah virus
Nipah virus (NiV) has surfaced in Kerala yet again, making this the eighth appearance in as many years. Whether virus spillovers (single index case, with no secondary cases in the community), or outbreaks (spillover with subsequent cases), Kerala has primed its response to the virus, seamlessly managing early detection, limiting the transmission and successfully saving lives. However, in all these encounters with NiV, researchers have identified several missing links or knowledge gaps. These pertain to the exact virus spillover mechanism from bats ( the fruit bats of the Pteropus species are the proven natural reservoir hosts of NiV) to humans; the recurrence of the spillover events/outbreaks in a specific geographic belt in northern Kerala and how exactly human behaviour, land use and bat ecology interactions are facilitating the virus spillovers. 'We have toyed with several hypotheses regarding the spillover mechanism. Are direct spillovers possible in areas near bat colonies , such as through droplet transmission from bat secretions or poop? Can individuals be indulging in high-risk behaviours, such as consuming bat meat (evidence of NiV in internal organs of bats has been reported)?,' said T.S. Anish, a public health expert who heads the Kerala One Health Centre for Nipah Research and Resilience, Kozhikode. The possibility that NiV transmission to humans could be through fruits bitten by bats has remained conjecture at best because NiV has never been isolated in any fruit samples collected and tested during outbreak investigations in Kerala. NiV RNA has been detected in date palm sap in Bangladesh but live virus has never been isolated from any field samples. But the link between consumption of raw date palm sap in Bangladesh and human NiV infections is strongly supported by epidemiological and experimental evidence. Also, as NiV is an enveloped virus, its ability to remain infectious on a fruit in an outdoor environment is extremely fragile, said Dr. Anish Intermediate hosts? 'Our current thinking about NiV spillovers strongly leans to the fact that there is an indirect transmission route to humans, involving an indirect host. Ephrin B2, the main cell receptor used by NiV for infecting host cells is highly conserved in all mammals, which means that all animals like dogs or cattle or pigs could harbour the virus, as has been demonstrated in Malaysia and Bangladesh,' he pointed out. None of the animal samples sent so far to the National Institute of High Security Animal Diseases in Bhopal have so far turned out to be NiV positive. However, it is also a fact that NiV research is relatively nascent and that the research institutions in the country, including the National Institute of Virology, are still in the process of developing antibody markers and testing assays specific to NiV. PVNT platform Thus, while Kerala's public health response against NiV infections has been effective, the development of a novel pseudovirus neutralization test (PVNT) platform, based on a Vesicular Stomatitis Virus (VSV) system at the State's Institute of Advanced Virology (IAV), Thonnakkal has opened up new research possibilities on Nipah. IAV has developed a novel way of generating non-infectious Nipah virus-like particles (VLPs) as well as pseudovirions in the laboratory, which mimic the wild type NiV. These engineered 'ghost viruses' carry most of the characteristics of the virus, including the NiV structural proteins G, F, and M, except their ability to replicate (because it lacks the viral genome). VLPs and pseudovirions have long been recognised as effective platforms for studying cell binding and entry kinetics of the virus. These VLPs and pseudovirions mimic viral entry but can only undergo a single round of infection and cannot replicate and reproduce infectious viruses, making them safe to handle in standard Biosafety Level 2 (BSL-2) facilities. PVNT-based serological survey 'We are proposing a pseudovirus neutralisation assay-based serological survey among potential intermediate animal hosts and high-risk human populations in areas of previous NiV spillovers, with the collaboration of various stakeholders, including the departments of Health, Animal Husbandry, Forests and wildlife. The proposal is to collect healthy domestic animal blood samples (cattle, pigs, goats, dogs and cats) and human samples from within a few km radius of Nipah hotspots,' E. Sreekumar, the Director of IAV, told The Hindu. Serum samples will be tested using the IAV's VSV-based PVNT assays. The assay measures the ability of IgG antibodies in human/animal serum to neutralise these pseudovirions, thereby preventing infection of target cells. Infectivity and neutralisation, is quantified by measuring the expression of a reporter gene incorporated into the pseudovirus genome Positive PVNT results will indicate the potential of those animal species as intermediary hosts and such samples will be further tested against live Nipah virus in a BSL-4 facility with the help of NIV, Pune. This study is expected to provide robust data on NiV seroprevalence in high-risk human and animal populations in Kerala and open the doors to the mystery of NiV disease spillover and transmission pattern in the State. Futuristically, the successful validation of serological data and its integration with geo-spatial analysis will enhance Kerala's diagnostic and surveillance capabilities for NiV, it is hoped
Time of India
14-06-2025
- Health
- Time of India
How stress impacts sleep and memory; here's what researchers say
Source: Researchers have spent years studying why stress often disrupts people's sleeping schedules, causing tossing and turning at night. They have also examined how stress might reduce our ability to recall important information the next day. Our mind tends to be stuck around things about which we're stressing over day and night. It affects the overall routine of our day and makes us feel as if we're trapped in a cage. According to Shinjae Chung, from the University of Pennsylvania, led a study to explore a neural pathway in male mice that stress may influence to cause sleep and memory disturbances. When stress hits the brain Stress affects more than just emotional reactions- it also triggers physical changes in the brain. One major key area that is affected in our brain is the hypothalamus' paraventricular nucleus (PVN), which helps the body respond to threats by sending signals and releasing hormones. When the affected area, PVN, detects stress, it can disrupt sleeping patterns and block healthy memory formation, setting off a chain that impacts overall well-being. Link between stress, sleep and memory Neuroscientists studied the effects of stimulating the PVN, discovering its connection to the lateral hypothalamus (LH), which regulates hunger and wakefulness. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Pinga-Pinga e HBP? Tome isso 1x ao dia se tem mais de 40 anos Portal Saúde do Homem Clique aqui Undo 'Activating CRHPVN neurons impairs memory performance and increases wakefulness, whereas inhibiting CRHPVN neurons during stress improves memory and sleep,' said Chung. By artificially stimulating neurons in mice, they observed reduced sleep and impaired spatial memory. On the other hand, blocking these neurons during stress improved memory and sleep, suggesting a key link between PVN activity, sleep patterns, and cognitive function. Stress affects sleep cycle and weakens memory Stress not only reduces sleep but also impairs memory. When PVN neurons are active, memory deficits occur. This suggests that any disruption around the hypothalamus affects how the brain stores information. Even mild stress can overactive molecular pathways, shifting towards survival and leaving normal processes like memory compromised. The brain depends on a tight rhythm of sleep-wake cycles and memory consolidation routines, which CRH neurons in the PVN seem to interrupt, re-routing energy towards immediate survival priorities. This shift disrupts normal rest patterns and blocks efficient memory processing, potentially leading to long-term effects on mental clarity and emotional balance. Handling stress carefully improves sleeping patterns By blocking stress-linked neurons, researchers observed calm behavior and slightly improved sleep in mice, as well as enhanced object recognition. One potential approach involves modulating Corticotropin-Releasing Hormone (CRH) signals, which triggers the stress response. They speculated that adjusting CRH activity in the PVN circuit might help restore sleep patterns and preserve memory function. Breaking the cycle of chronic stress Further research is still required to determine how often the hypothalamic circuit becomes overworked and to investigate the timing, dodge, and potential side effects of therapies. This discovery could lead to new therapies that promote healthy sleep and protect memory, particularly for individuals with anxiety disorders. Also read | What is Mouth Larvae: Know its causes, symptoms, prevention strategies and treatment One step to a healthier you—join Times Health+ Yoga and feel the change
