Distribution of intranasal instillations in mice: effects of volume, time, body position, and anesthesia

Intranasal instillation techniques are used to deliver various substances to the upper and lower respiratory tract (URT and LRT) in mice. Here, we quantify the relative distribution achieved with intranasal delivery of a nonabsorbable tracer,99mTc-labeled sulfide-colloid. Relative distribution was determined by killing mice after instillation and quantifying the radioactivity in dissected tissues using gamma scintigraphy. A significant effect of delivery volume on relative distribution was observed when animals were killed 5 min after instillation delivered under gas anesthesia. With a delivery volume of 5 μl, no radiation was detected in the LRT; this increased to a maximum of 55.7 ± 2.5% distribution to the LRT when 50 μl were delivered. The majority of radiation not detected in the LRT was found in the URT. Over the course of the following 1 h, radiation in the LRT remained constant, while that in the URT decreased and appeared in the gastrointestinal tract. Instillation of 25 μl into anesthetized mice resulted in 30.1 ± 6.9% distribution to the LRT, while only 5.3 ± 1.5% ( P < 0.05) of the same volume was detected in the LRT of awake mice. Varying the body position of mice did not affect relative distribution. When using intranasal instillation, the relative distribution between the URT and LRT and the gastrointestinal tract is heavily influenced by delivery volume and level of anesthesia.

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Functional profiling of COVID-19 respiratory tract microbiomes

Scientific Reports ◽

10.1038/s41598-021-85750-0 ◽

2021 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Niina Haiminen ◽

Filippo Utro ◽

Ed Seabolt ◽

Laxmi Parida

Keyword(s):

Respiratory Tract ◽

Carbohydrate Metabolism ◽

Lower Respiratory Tract ◽

Viral Infections ◽

Lavage Fluid ◽

Degradation Pathway ◽

Community Acquired Pneumonia ◽

The Body ◽

Sequencing Data ◽

Functional Profiling

AbstractIn response to the ongoing global pandemic, characterizing the molecular-level host interactions of the new coronavirus SARS-CoV-2 responsible for COVID-19 has been at the center of unprecedented scientific focus. However, when the virus enters the body it also interacts with the micro-organisms already inhabiting the host. Understanding the virus-host-microbiome interactions can yield additional insights into the biological processes perturbed by viral invasion. Alterations in the gut microbiome species and metabolites have been noted during respiratory viral infections, possibly impacting the lungs via gut-lung microbiome crosstalk. To better characterize microbial functions in the lower respiratory tract during COVID-19 infection, we carry out a functional analysis of previously published metatranscriptome sequencing data of bronchoalveolar lavage fluid from eight COVID-19 cases, twenty-five community-acquired pneumonia patients, and twenty healthy controls. The functional profiles resulting from comparing the sequences against annotated microbial protein domains clearly separate the cohorts. By examining the associated metabolic pathways, distinguishing functional signatures in COVID-19 respiratory tract microbiomes are identified, including decreased potential for lipid metabolism and glycan biosynthesis and metabolism pathways, and increased potential for carbohydrate metabolism pathways. The results include overlap between previous studies on COVID-19 microbiomes, including decrease in the glycosaminoglycan degradation pathway and increase in carbohydrate metabolism. The results also suggest novel connections to consider, possibly specific to the lower respiratory tract microbiome, calling for further research on microbial functions and host-microbiome interactions during SARS-CoV-2 infection.

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Endoscopic Treatment of Amyloidosis of the Nasopharynx

American Journal of Rhinology ◽

10.2500/105065895781874033 ◽

1995 ◽

Vol 9 (1) ◽

pp. 43-48 ◽

Cited By ~ 4

Author(s):

Jonathan A. Lesserson ◽

Douglas G. Finn

Keyword(s):

Gastrointestinal Tract ◽

Oral Cavity ◽

Respiratory Tract ◽

Head And Neck ◽

Endoscopic Treatment ◽

Lower Respiratory Tract ◽

English Literature ◽

Rare Presentation ◽

Localized Amyloidosis ◽

Neck Area

Amyloidosis of the nasopharynx is a rare presentation of localized amyloidosis. The majority of systemic amyloidosis cases involve the heart, gastrointestinal tract, kidneys, and upper and lower respiratory tract. Localized amyloidosis involving only one site is less common, but has been observed in the head and neck area, particularly in the larynx or the oral cavity. Amyloidosis in the nasopharynx has been reported in only seven previous cases in the English literature.

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UK B.1.1.7 variant exhibits increased respiratory replication and shedding in nonhuman primates

10.1101/2021.06.11.448134 ◽

2021 ◽

Author(s):

Kyle Rosenke ◽

Friederike Feldmann ◽

Atsushi Okumura ◽

Frederick Hansen ◽

Tsing-Lee Tang-Huau ◽

...

Keyword(s):

Gastrointestinal Tract ◽

Respiratory Tract ◽

Respiratory Disease ◽

Lower Respiratory Tract ◽

Nonhuman Primates ◽

Infectious Virus ◽

Clinical Presentation ◽

Viral Rna ◽

The Uk ◽

Green Monkeys

The continuing emergence of SARS-CoV-2 variants calls for regular assessment to identify differences in viral replication, shedding and associated disease. In this study, African green monkeys were infected intranasally with either a contemporary D614G or the UK B.1.1.7 variant. Both variants caused mild respiratory disease with no significant differences in clinical presentation. Significantly higher levels of viral RNA and infectious virus were found in upper and lower respiratory tract samples and tissues from B.1.1.7 infected animals. Interestingly, D614G infected animals showed significantly higher levels of viral RNA and infectious virus in rectal swabs and gastrointestinal tract tissues. Our results indicate that B.1.1.7 infection in African green monkeys is associated with increased respiratory replication and shedding but no disease enhancement similar to human B.1.1.7 cases.

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Estimation of volume of epithelial lining fluid recovered by lavage using urea as marker of dilution

Journal of Applied Physiology ◽

10.1152/jappl.1986.60.2.532 ◽

1986 ◽

Vol 60 (2) ◽

pp. 532-538 ◽

Cited By ~ 713

Author(s):

S. I. Rennard ◽

G. Basset ◽

D. Lecossier ◽

K. M. O'Donnell ◽

P. Pinkston ◽

...

Keyword(s):

Respiratory Tract ◽

Bronchoalveolar Lavage ◽

Lower Respiratory Tract ◽

Time Course ◽

Apparent Volume ◽

The Body ◽

Albumin Concentration ◽

Epithelial Lining ◽

Epithelial Lining Fluid ◽

A Value

Bronchoalveolar lavage is a powerful technique for sampling the epithelial lining fluid (ELF) of the lower respiratory tract but also results in a significant dilution of that fluid. To quantify the apparent volume of ELF obtained by bronchoalveolar lavage, urea was used as an endogenous marker of ELF dilution. Since urea diffuses readily through the body, plasma and in situ ELF urea concentrations are identical; thus ELF volume can be calculated using simple dilution principles. Using this approach, we determined that with a standard lavage procedure, the volume of ELF recovered from a normal human is 1.0 +/- 0.1 ml/100 ml of recovered lavage fluid. Time course experiments in which the saline used for lavage was permitted to remain in the lower respiratory tract for various “dwell times” suggested that diffusion of urea from sources other than recovered ELF can contribute to the total urea recovered resulting in an overestimate of the volume of ELF recovered. Thus, while reasonably accurate, the volume of ELF determined by urea must be considered an overestimate, or “apparent” volume. The ELF albumin concentration based on the apparent ELF volume was 3.7 +/- 0.3 mg/ml, a value that is in good agreement with direct measurements made by other techniques in experimental animals. The density of all inflammatory and immune effector cells on the epithelial surface of the lower respiratory tract, based on the apparent ELF volume, was 21,000 +/- 3,000 cells/microliter, a value that is twofold greater than that in blood.(ABSTRACT TRUNCATED AT 250 WORDS)

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Results of 5-year monitoring of the circulation of seasonal Сoronaviruses in hospitalized children in the pre-pandemic period

CHILDREN INFECTIONS ◽

10.22627/2072-8107-2021-20-1-5-11 ◽

2021 ◽

Vol 20 (1) ◽

pp. 5-11

Author(s):

V. N. Timchenko ◽

V. F. Sukhovetskaya ◽

T. M. Chernova ◽

T. A. Kaplina ◽

M. D. Subbotina ◽

...

Keyword(s):

Gastrointestinal Tract ◽

Confidence Interval ◽

Respiratory Tract ◽

Acute Respiratory Infection ◽

Lower Respiratory Tract ◽

Age Groups ◽

Hospitalized Children ◽

Respiratory Viral Infection ◽

Acute Respiratory Viral Infection ◽

Combined Infection

Coronaviruses can cause damage to various parts of the respiratory system, gastrointestinal tract, and other organs and systems.The aim of the study: to monitor the circulation of seasonal coronaviruses in hospitalized children in the pre-pandemic period.Materials and methods: real-time multiplex PCR was used to test samples of nasopharyngeal mucus from 2188 patients aged 1 monthto 17 years, hospitalized with acute respiratory infection in 2014—2018. The results are presented with the indication of the fractions (%) and the calculation of the 95% confidence interval according to Klopper-Pearson. The differences between the groups were evaluated using the Pearson χ2 test. The differences in the groups were considered statistically significant at the level of the criterion p< 0.05.Results: monitoring of the circulation of pathogens of acute respiratory viral infection (ARVI) during 5 epidemic seasons showed that the appearance of a new subtype of coronavirus in 2019 was preceded by a gradual displacement of influenza, RS-and bocavirus infections from the circulation due to a statistically significant increase in the proportion of seasonal coronaviruses from 3.6% in 2014—2015 to 10.8% in the prepandemic season 2018—2019 (p= 0.007). The circulation of seasonal coronaviruses had a distinct seasonality (november-april)with the peak of registration in february (28.4%) and march (36.7%). Seasonal coronaviruses were detected in 7.3% of hospitalized children with ARVI, with a predominance in the age groups under 2 years (58.2%) and 3—6 years (25.4%). Hospitalization was more often required for patients with lower respiratory tract lesions (58.2%), a fifth of which was pneumonia (21.8%). In most children, ARVI caused by coronaviruses occurred as a monoinfection (79.9%), combined infection with other pathogens was observed in 20.1% of cases with fluctuations from 18.2% to 28.6% in different epidemic seasons. Viral associations are most common in young children (85.2%).

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