Biology, Engineering, Medicine and Science Reports

Crocodile Tear Syndrome Post Microvascular Decompression of the Trigeminal Nerve: A Case Report and Literature Review

Mohammad Hameed Abul, Mohit Arora, Chandrasekaran Kaliaperumal — Mon, 15 May 2023 00:00:00 -0400

Background: Crocodile Tear Syndrome (CTS) is a condition characterised by excessive tear secretion in response to eating, drinking, or smelling foods. Traditionally, acquired cases are most commonly reported following facial nerve trauma or paralysis, or in slow-growing facial nerve tumours. More recently, it has been reported following vestibular Schwannoma surgery. We report the first case of crocodile tear syndrome following microvascular decompression of the trigeminal nerve. Case Presentation: A 61-year-old lady presented with excessive lacrimation and clear rhinorrhoea one month post-operatively from a re-do trigeminal microvascular decompression (MVD) surgery. The patient experienced similar symptoms following her initial surgery two years prior, which had resolved spontaneously. CT and MRI head, and comprehensive clinical examination showed no evidence of CSF leak from her retromastoid wound site. An ENT opinion was sought, and the patient was diagnosed with post-operative crocodile tear syndrome. Surgical technique and relevant imaging were reviewed for any possible explanation for the condition. We discuss the possible aetio-pathogenesis for the development of the condition following MVD procedure. Conclusion: We conclude that CTS should be considered in patients presenting with CSF rhinorrhoea following MVD of Trigeminal nerve after excluding CSF leak from the middle ear via eustachian tube. Treatment for CTS in this context may pose a challenge. The patient has undergone botulinum toxin injection of the lacrimal gland and will likely need long term follow up. This is the first documented case of CTS post microvascular decompression of the trigeminal nerve.

A Brief Report on Utility of N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) in Screening Patients at Risk of Atrial Fibrillation and Stroke

Arun HS Kumar — Mon, 15 May 2023 00:00:00 -0400

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a prohormone that is produced and released by the heart (ventricles) in response to alteration in pressure/strain/volume.[1-3] It is used as a biomarker of cardiac function and is involved in the regulation of fluid and electrolyte balance.1-3 When the heart is under stress or is experiencing decreased blood flow, the ventricular myocardium releases the precursor molecule proBNP, which is then cleaved (by a membrane-bound enzyme called corin) into B-type natriuretic peptide (BNP) and NT-proBNP in equimolar amounts.4,5 BNP is secreted into the blood and promotes vasodilation and diuresis, while NT-proBNP serves as a stable marker of cardiac function and is involved in the regulation of fluid and electrolyte balance.6,7 NT-proBNP synthesized in the cardiac ventricles as a prepropeptide (134 amino acids) undergoes several post-translational modifications, including signal peptide cleavage, propeptide cleavage, and glycosylation, before being released as the mature 76-amino acid NT-proBNP molecule.4,5 NT-proBNP is secreted into the bloodstream and is cleared primarily by the kidneys. NT-proBNP levels are influenced by a variety of factors, including age, sex, kidney function, and cardiac disease.8,9 Elevated levels of NT-proBNP are associated with an increased risk of cardiovascular events, such as heart failure, atrial fibrillation and stroke, and can be used as a diagnostic tool to identify individuals at risk of these conditions.6,10-12 The concentration NT-proBNP can be measured in serum/ plasma samples. The assays for NT-proBNP measurement typically use immunoassay techniques, such as Enzyme-Linked Immunosorbent Assay (ELISA) or Chemiluminescence Immunoassay (CLIA), which rely on the binding of specific antibodies to the NT-proBNP molecule. These assays are highly sensitive and specific, with low limits of detection and high precision, making them valuable tools for the diagnosis and management of cardiovascular disease.11,12.

Read more...

Contamination of Food by Nitrosamines and the Associated Public Health Risks

Arun HS Kumar — Mon, 15 May 2023 00:00:00 -0400

The presence of N-Nitrosamines (N-NAs) in food poses a serious risk to public health, according to a recent scientific opinion by the European Food Safety Authority (EFSA).1,2 These genotoxic compounds, which induce liver tumours in rodents, are found in various food categories, with 'meat and meat products' being the main contributor to dietary exposure.1-3 The EFSA assessment revealed that the Margin of Exposure (MOE) for the 10 carcinogenic N-NAs (NDMA, NMEA, NDEA, NDPA, NDBA, NMA, NSAR, NMOR, NPIP, and NPYR) in food was highly likely to be less than 10,000 for all age groups, indicating a significant health concern.1-3 However, the assessment was limited by uncertainties due to censored data and lack of information on some food categories. This highlights the need for continued monitoring of N-NAs in food and the implementation of mitigation measures to protect public health. The CONTAM Panel of the European Commission has conducted a scientific evaluation of the human health risks associated with the presence of N-NAs in food.1-3 N-NAs are formed in food through the reaction of nitrosating agents with amino-based substances under certain routine processing conditions (Figure 1). These compounds have been detected in various food products such as cured meats, processed fish, beverages, cheese, soy sauce, oils, processed vegetables, and human milk.4,5 Heat treatment during food processing can also increase the levels of N-NAs, particularly in meat and fish products.6,7 The CONTAM Panel has identified and characterized the hazards of 32 N-NAs, but the risk assessment was focused on 10 carcinogenic N-NAs found in food.1 These compounds have been shown to be absorbed and distributed in the bodies of experimental animals, primarily to the liver but also to lungs, kidneys, and brain.8,9 N-NAs are also known to cross the placenta, and fetal exposure to these compounds has been reported.10,11. Read more...

Unveiling the Mysteries of Gut CrAssphages: A Step Forward in Understanding the Human Virobiome

Arun HS Kumar — Mon, 15 May 2023 00:00:00 -0400

A recent study published in the journal Nature and as preprint has revealed a new structural atlas of gut crAssphages, a type of virus that is commonly found in the human gut microbiome.1,2 This ground breaking research sheds light on the structure and function of these viruses, which play a crucial role in the ecology of the human gut microbiome. The human gut microbiome is a complex and diverse ecosystem of microorganisms that play an important role in human health and disease. Viruses, including crAssphages, are an integral part of this ecosystem, but their structure and function have remained poorly understood until now. The study used a combination of cryo-electron microscopy and bioinformatics analysis to generate a high-resolution structural atlas of gut crAssphages.1,2 The results revealed a previously unknown structural organization, with unique features that distinguish them from other known viruses. The findings have important implications for understanding the ecology and evolution of the human gut microbiome. The crAssphages play a key role in controlling the populations of gut bacteria,3,4 and a better understanding of their structure and function could lead to new strategies for manipulating the microbiome to treat or prevent disease. Moreover, this research has significant implications for the field of virology as a whole. The discovery of new viruses and the elucidation of their structures and functions is critical for developing new antiviral therapies and vaccines. However, there are still many unanswered questions about the role of crAssphages in the human gut microbiome.5-7 For example, it is still unclear how these viruses interact with the host immune system and how they are transmitted from person to person. It is also unclear if crAssphages play any role in influencing the gut-brain and/or gut-cardiac axis. Considering their biphasic role in patients with obesity and metabolic syndrome8 it is likely that crAssphages may have an influence on gut-brain and/or gut-cardiac axis. Nonetheless, this study represents a significant step forward in understanding the structure and function of gut crAssphages and their role in the human microbiome. The insights gained from this research could ultimately lead to new strategies for manipulating the microbiome to improve human health and prevent disease. Read more...

Inaccurate Labelling of Melatonin Gummies: A Concerning Trend

Arun HS Kumar — Mon, 15 May 2023 00:00:00 -0400

Melatonin gummies have gained popularity as a sleep aid and are widely available over-the-counter.1,2 However, a recent analysis of 25 melatonin gummy products has revealed a concerning trend of inaccurate labelling, raising important questions about product quality, consumer safety, and regulatory oversight.3 This editorial aims to highlight the findings of the analysis and discuss the implications for both manufacturers and consumers. Read more...

Pitfalls in Diagnosis of Shunt Malfunction in Children

Jigisha Moudgil-Joshi, Tafadzwa Mandiwanza, Chandrasekaran Kaliaperumal — Mon, 15 May 2023 00:00:00 -0400

Background: In children with a potential shunt malfunction, pediatricians and emergency physicians are often the first to assess these children prior to neurosurgical referral. Most shunts fail within the first year (67%), with 14% of children having a shunt failure within the first month of insertion, and 40% within the second year of insertion. Classical symptoms of raised ICP, such as nausea, vomiting, coma and bulging fontanelle have a high predictive value for shunt failure, but are not always present. Some patients may be asymptomatic of shunt failure and the age of the patient will also confound this symptom spectrum. Clinical signs of shunt failure are well varied and age dependent. This article presents a series of four cases of shunted patients with atypical presentations of shunt malfunction. Materials and Methods: Clinical, radiological and surgical data of the patients were collected to demonstrate atypical presentations of shunt malfunction. All shunt malfunctions were confirmed upon review of the shunt in the operating theatre. Results: Four patients are shown to have atypical presentations of shunt malfunction. The first child was completely well despite an incidental finding of papilloedema on routine follow up, despite the lack of clinical and radiological evidence for shunt malfunction. The second child was completely well with a minor intermittent CSF leak at the drain wound. The third was an expanding pseudomeningocele after tumor resection. The final child had an expanding lower back pseudomeningocele but was otherwise well. All patients had resulting successful shunt revisions. Conclusion: It is important for neurosurgeons, paediatricians and emergency doctors to be able to identify these atypically presenting children and to correct their shunt malfunction to prevent long-term complications of insidious raised ICP, such as blindness or worsening of pre-existing neurological deficits and more importantly to prevent the child having a rapid and devastating decompensation.