Human Respiratory Tract Research Articles

Haemophilus Influenzae Epididymo-Orchitis and Bacteraemia in an Immunocompetent Patient.

Epididymitis is a common cause of scrotal pain in adults, with coliform bacteria being the most common isolated organisms in patients older than 35. A 51-year-old healthy patient presented with scrotal pain and swelling, and was found to have epididymo-orchitis and bacteraemia caused by Haemophilus influenzae, which has not previously been reported as a cause of epididymo-orchitis and bacteraemia in immunocompetent patients. Diagnostic studies can help confirm the diagnosis and detect the causative pathogen. In all suspected cases, a urinalysis, urine culture and a urine or urethral swab for nucleic acid amplification tests (NAATs) for Neisseria gonorrhoeae and Chlamydia trachomatis should be performed. Colour Doppler ultrasonography often shows an enlarged thickened epididymis with increased Doppler wave pulsation in epididymitis. H. influenzae are pleomorphic gram-negative rods that commonly colonise the human respiratory tract and are associated with a number of clinical conditions. H. influenzae has been reported as a cause of epididymo-orchitis in prepubertal boys, and in few cases were associated with positive blood cultures. In adults, H. influenzae has been isolated before from urine samples or urethral swabs in patients with epididymitis or epididymo-orchitis. This case highlights the possibility of H. influenzae causing epididymo-orchitis and bacteraemia in immunocompetent patients. Healthcare providers should consider H. influenzae in the differential diagnosis of epididymitis and epididymo-orchitis in both immunocompetent and immunocompromised patients. H. influenzae can cause epididymo-orchitis and bacteraemia in immunocompetent patients. This has not been previously reported.H. influenzae should be considered in the differential diagnosis of epididymitis and epididymo-orchitis in both immunocompromised and immunocompetent patients.Healthcare providers should be aware of the increasing incidence of epididymitis and epididymo-orchitis caused by non-coliform bacteria in patients older than 35 years, especially in immunocompromised patients.

In silico immunoinformatics based prediction and designing of multi-epitope construct against human rhinovirus C

Human rhinovirus C (HRV-C) is an RNA virus infecting human respiratory tract. It is associated with complexities like asthma, chronic obstructive pulmonary disease, and respiratory damage. HRV-C has many serotypes. Till date there is no vaccine. Despite some limitations, corticosteroids, bronchodilators, and common cold medicines are used to treat HRV-C infections. Here, we have used immunoinformatics approach to predict suitable cytotoxic T-cell, helper T-cell and linear B-cell epitopes from the most antigenic protein. VP2 protein of Rhinovirus C53 strain USA/CO/2014-20993 was found to be most antigenic. The multi-epitope construct was designed using the best CTL, HTL and linear B-cell epitopes and attaching them with adjuvant and linkers. Interferon-gamma inducing epitopes and conformational B-cell epitopes were also predicted from the construct. Physicochemical and structural properties of the construct were satisfactory. Binding pockets were identified that could be the targets for designing effective inhibitors. Molecular docking revealed strong binding affinity of the construct with human Toll-like receptors 2 and 4. Normal mode analysis divulged stability of the docked complex. Codon optimization, in silico cloning and immune simulation analysis demonstrated suitability of the construct. These findings are likely to aid in vitro studies for developing vaccine against HRV-C.

Characterisation of polycyclic aromatic hydrocarbons associated with indoor PM0.1 and PM2.5 in Hanoi and implications for health risks

Polycyclic aromatic hydrocarbons (PAHs) associated with indoor PM pose a high risk to human health because of their toxicity. A total of 160 daily samples of indoor PM2.5 and PM0.1 were collected in Hanoi and analysed for 15 PAHs. In general, the concentrations of carcinogenic PAHs (car-PAHs) accounted for 21% ± 2%, 19.1% ± 2%, and 26% ± 3% of the concentrations of 15 PAHs in PM2.5, PM0.1-2.5, and PM0.1, respectively. Higher percentages of car-PAHs were found in smaller fractions (PM0.1), which can be easily deposited deep in the pulmonary regions of the human respiratory tract. The concentrations of 15 PAHs were higher in winter than in summer. The most abundant PAH species were naphthalene and phenanthrene, accounting for 11%–21% and 19%–23%, respectively. The PAH content in PM0.1 was almost twice as high as those in PM2.5 and PM0.1-2.5. Principal component analysis found that vehicle emissions and the combustion of biomass and coal were the main outdoor sources of PAHs, whereas indoor sources included cooking activities, the combustion of incense, scented candles, and domestic uses in houses. According to the results, 60%–90% of the PM0.1-bound BaP(eq) was deposited in the alveoli region, whereas 63%–75% of the PM2.5-bound BaP(eq) was deposited in head airways (HA), implying that most of the particles deposited in the HA region were PM0.1-2.5. The contributions of dibenz[a,h]anthracene and benzo[a]pyrene were dominant and contributed from 36% to 51% and 31%–50%, respectively, to the carcinogenic potential, whereas benzo[a]pyrene contributed from 30% to 49% to the mutagenic potential for both size fractions. The incremental lifetime cancer risk, simulated by Monte Carlo simulation, was within the limits set by the US EPA, indicating an acceptable risk for the occupants. These results provide an additional scientific basis for protecting human health from exposure to indoor PAHs.

Toxic Particles Deposition in the Human Respiratory Tract under Natural Inspiratory Flow

Toxic particle (PM2.5) deposition in the human respiratory tract is investigated under natural inspiratory flow. The flow physics of nostrils is asymmetric, and its effect on particle deposition needs prompt attention. An ideal 3-D CT-scan-based geometrical model of the human respiratory tract is re-constructed from the nasal cavity to the 7th generation bronchi. The pulsatile numerical simulation is performed with light (10 L/min) and moderate (40 L/min) inspiratory flow. The Lagrangian method is adopted to compute particle deposition fraction (DPF) in the airways. The suspended particle mass of 300 µg/m3 (poor air quality) (dp = 2.5 µm in diameter) is released from the inlet of airways at every time interval (∆t). The results revealed that the pattern of particle transportation is not similar in both the bronchus and particle hot spots are constituted in the airways. Findings guide optimal targeted drug delivery and the assessment of ventilation illness under hazardous exposure in distinct populations.

Amino acid substitution L232F in non-structural protein 6 identified as a possible human-adaptive mutation in clade B MERS coronaviruses.

Viral host adaptation plays an important role in inter-species transmission of coronaviruses and influenza viruses. Multiple human-adaptive mutations have been identified in influenza viruses but not so far in MERS-CoV that circulates widely in dromedary camels in the Arabian Peninsula leading to zoonotic transmission. Here, we analyzed clade B MERS-CoV sequences and identified an amino acid substitution L232F in nsp6 that repeatedly occurs in human MERS-CoV. Using a loss-of-function reverse genetics approach, we found the nsp6 L232F conferred increased viral replication competence in vitro, in cultures of the upper human respiratory tract ex vivo, and in lungs of mice infected in vivo. Our results showed that nsp6 L232F may be an adaptive mutation associated with zoonotic transmission of MERS-CoV. This study highlighted the capacity of MERS-CoV to adapt to transmission to humans and also the need for continued surveillance of MERS-CoV in camels.

Prevalence of extended-spectrum and metallo β-lactamase production in Pseudomonas aeruginosa isolate

Due to intrinsically developed resistance in Pseudomonas aeruginosa, with extended-spectrum β-lactamase (ESBL) and metallo β-lactamase (MBL)-producing genes, such P. aeruginosa isolates have become a major threat to public health. Therefore, in this study, the synthesis of MBL and the prevalence of ESBL were observed phenotypically in P. aeruginosa using the DDST test. Seventy-six out of 120 strains of P. aeruginosa were obtained from animal milk and human sputum, blood, respiratory tract, and abscess. A total of 76 isolates (51.31%) synthesized ESBLs, 48.6% produced MBL, and 68.6% produced AmpC. The genotypic prevalence of MBL and ESBL for bla TEM-1 and bla IMP-1 was 20.12 and 17.8%, respectively. The results demonstrated a considerable prevalence of MBL and ESBL among P. aeruginosa isolates, with different enzyme variants detected in each sample. The data was significant for the P values less than 0.05.

Screening Dolosigranulum pigrum Strains for Secreted Factors that InhibitStaphylococcus aureus

Abstract Background Staphylococcus aureus is a leading cause of community-associated and hospital-acquired infections, and methicillin-resistant S. aureus (MRSA) is a significant global health concern. Approximately 30% of the human population is asymptomatically colonized by S. aureus in the upper respiratory tract, with this colonization typically preceding respiratory infections caused by S. aureus. Dolosigranulum pigrum is a putatively beneficial bacterium that is a frequent colonizer of the human upper respiratory tract. The presence and abundance of D. pigrum in the upper respiratory tract has been negatively associated with S. aureus colonization among infants and young children. Additionally, in cocultivation experiments, D. pigrum has been shown to inhibit S. aureus growth, although the mechanisms for this antistaphylococcal activity have not been identified. Methods We hypothesized that D. pigrum strains secrete a protein factor that inhibits growth of S. aureus. To evaluate this hypothesis, we screened D. pigrum strains for antistaphylococcal activity using a plate-based cocultivation assay. Briefly, 5 µL aliquots of D. pigrum strains in liquid brain heart infusion (BHI) medium (OD600=0.3) were spotted onto a BHI agar plate and incubated at 37°C and 5% CO2 for 48 hours. Next, 5 µL aliquots of S. aureus strain Newman in liquid BHI medium (OD600=0.1) were spotted onto this plate at varying distances from the D. pigrum inocula and incubated at 37°C and 5% CO2 for an additional 24 hours. Secretion of an anti-staphylococcal factor was assessed based on the presence of a visible zone of inhibition between the D. pigrum and S. aureus inocula. We excised agar fragments adjacent to 4 inhibitory and 4 non-inhibitory D. pigrum strains and submitted these samples for liquid chromatography with tandem mass spectrometry (LC-MS/MS)-based proteomics. The proteomic data were searched against the TrEMBL D. pigrum database and a common contaminant/spiked protein database, and signal intensity values for identified peptides were quantified. Results Four of 43 (9%) D. pigrum strains screened in cocultivation assays consistently produced a zone of inhibition against S. aureus. We identified 531 unique proteins from proteomic analysis of agar fragments, including 28 D. pigrum proteins that were significantly more abundant in zones adjacent to inhibitory vs. non-inhibitory strains. The most differentially abundant protein was an S8 family serine protease (112 times more abundant in fragments adjacent to inhibitory strains). Using previously generated whole-genome sequencing data from these 43 D. pigrum strains, we found that the gene encoding this serine protease was present in 41 of 43 (95%) D. pigrum strains, including all 4 strains that were inhibitory in the cocultivation assay. The predicted active domain for the final protein was highly conserved across strains. Other secreted D. pigrum proteins that were more abundant in gel fragments adjacent to inhibitory strains included a peptidoglycan hydrolase and 7 uncharacterized D. pigrum proteins. Conclusion D. pigrum inhibits S. aureus growth in vitro through secretion of inhibitory factors in a strain-dependent manner. We identified an S8 family serine protease as a possible candidate mechanism for the anti-staphylococcal activity of D. pigrum. Future experiments will screen cell-free supernatants from inhibitory D. pigrum strains for S. aureus inhibition and evaluate the effect of protease inhibitor treatment on the antistaphylococcal activity of these supernatants.

Examining respiratory comfort in vernacular and conventional buildings

The study examines the role of air temperature and humidity on heat and moisture exchanges in the human respiratory tract. A human respiratory tract model was built to solve for heat and mass balance under varying indoor temperature (Ti) and relative humidity (RHi) values. Ti and RHi from on-field measurements from Vernacular (Adobe) and Conventional (Brick/RCC) buildings were used as input parameters to this model for computation of temperature (Ta in °C) water vapor concentration (Ca in mg/l) at different segments of the respiratory tract. Results indicate that at the same temperature, relative humidity has a significant bearing on respiratory air conditioning. Also, at a given length of the respiratory tract, the percentage of heating and humidification achieved was higher in vernacular room conditions compared to the conventional room. Excess water vapor loss from the mucus layer in the deeper airway conduits restricts mucociliary clearance causing respiratory difficulties, predominantly in cold regions. Comfortable respiration is an important indicator of health and productivity; however, it is not presently incorporated for indoor comfort evaluation. Insights from the study can lead to recommendations for material selection for the design of comfortable, healthy indoor environments.

Seasonal Disparities of Human Health Risk and Particle-Bound Metal Characteristics Associated with Atmospheric Particles in a Fishery Harbor.

The effects of atmospheric pollution from ship emissions have been considered for several harbors worldwide. The health risk assessment and source apportionment of particle-bound metals in a fishery harbor were investigated in this study. The most abundant metal elements in particulate matter (PM) on all sampling days in three seasons were Fe (280.94 ± 136.93 ng/m3), Al (116.40 ± 71.25 ng/m3), and Zn (110.55 ± 26.70 ng/m3). The ratios of V/Ni were 1.44 ± 0.31, 1.48 ± 0.09 and 1.87 ± 0.06 in PM10, PM2.5, and PM1, respectively. Meanwhile, the ratios higher than 1 indicated that fuel oil combustion from ship emission in fishery harbor. The highest deposits of total particle-bound metals in the human respiratory tract were in the head airway (HA), accounting for 76.77 ± 2.29% of the total particle-bound metal concentration, followed by 5.32 ± 0.13% and 2.53 ± 0.15% in the alveolar region (AR) and tracheobronchial (TB) region, respectively. The total cancer risk (CR) of inhalation exposure to local residents exceeded 10-6. Mean total CR values followed the sequence: autumn (1.24 × 10-4) > winter (8.53 × 10-5) > spring (2.77 × 10-6). Source apportionment of related metal emissions was mobile pollution emissions (vehicle/boat) (37.10-48.92%), metal fumes of arc welding exhaust (19.68-34.42%), spray-painting process (12.34-16.24%), combustion emissions (6.32-13.12%), and metal machining processes (9.04-16.31%) in Singda fishing harbor. These results suggest that proper control of heavy metals from each potential source in fishing harbor areas should be carried out to reduce the carcinogenic risk of adverse health effects.

Mathematical solutions in internal dose assessment: A comparison of Python-based differential equation solvers in biokinetic modeling

In biokinetic modeling systems employed for radiation protection, biological retention and excretion have been modeled as a series of discretized compartments representing the organs and tissues of the human body. Fractional retention and excretion in these organ and tissue systems have been mathematically governed by a series of coupled first-order ordinary differential equations (ODEs). The coupled ODE systems comprising the biokinetic models are usually stiff due to the severe difference between rapid and slow transfers between compartments. In this study, the capabilities of solving a complex coupled system of ODEs for biokinetic modeling were evaluated by comparing different Python programming language solvers and solving methods with the motivation of establishing a framework that enables multi-level analysis. The stability of the solvers was analyzed to select the best performers for solving the biokinetic problems. A Python-based linear algebraic method was also explored to examine how the numerical methods deviated from an analytical or semi-analytical method. Results demonstrated that customized implicit methods resulted in an enhanced stable solution for the inhaled 60Co (Type M) and 131I (Type F) exposure scenarios for the inhalation pathway of the International Commission on Radiological Protection (ICRP) Publication 130 Human Respiratory Tract Model (HRTM). The customized implementation of the Python-based implicit solvers resulted in approximately consistent solutions with the Python-based matrix exponential method (expm). The differences generally observed between the implicit solvers and expm are attributable to numerical precision and the order of numerical approximation of the numerical solvers. This study provides the first analysis of a list of Python ODE solvers and methods by comparing their usage for solving biokinetic models using the ICRP Publication 130 HRTM and provides a framework for the selection of the most appropriate ODE solvers and methods in Python language to implement for modeling the distribution of internal radioactivity.

Real-time PCR for indication of representatives of <i>Chlamydiales</i> order: needs for development and main analytical characteristics of the method

Respiratory diseases occupy a dominant position in the structure of morbidity, often the etiology of which remains unclear. This situation is largely due to the lack of knowledge of the entire spectrum of pathogens that cause respiratory diseases, as well as the lack of approaches to their indication and identification. Thanks to constant progress of molecular biology, a number of bacteria related to chlamydia have been identified, some of which are associated with human respiratory diseases, including chlamydia-like microorganisms. The role of atypical pathogens such as chlamydia-like microorganisms Parachlamydia acanthamoebae, and Simkania negevensis in the pathology of the human respiratory tract is still not fully understood. A real-time PCR-based method has been developed and optimized. It is capable of detecting the DNA of both chlamydia and chlamydia-like microorganisms (Parachlamydia acanthamoebae and Simkania negevensis). The method is characterized by high specificity and reproducibility, as well as by analytical sensitivity at a level of 8.7∙103 GE/ml. Its use will make it possible to assess the contribution of these atypical pathogens to the etiological structure of infectious diseases of the respiratory tract.

A Rare Case of HACEK Endocarditis in the Context of a Permanent Pacemaker

Introduction: Infective endocarditis (IE) is a serious medical condition that can lead to high morbidity and mortality rates. The prevalence of healthcare-associated IE is increasing due to the use of therapeutic devices, such as intravascular catheters and cardiac devices. The HACEK group of bacteria, are commonly found in human respiratory and genitourinary tracts, are low virulence and fastidious organisms that are associated with blood culture-negative endocarditis. Proper diagnosis requires a combination of clinical, microbiological, and imaging results. The following study presents a case of atypical device-associated IE caused by Haemophilus influenzae in a 56-year-old man with a permanent pacemaker. Methodology: description of a clinical problem, its diagnosis, management, and outcome, accompanied with a literature review. Conclusion: This study highlights the importance of considering the HACEK group of bacteria in culture-negative IE cases and the use of advanced imaging techniques in diagnosis to prevent further complications and improve patient outcomes.

Impact of C- and N-terminal protection on the stability, metal chelation and antimicrobial properties of calcitermin

The main limitation to the use of antimicrobial peptides (AMPs) as regular drugs, against antibiotic and antifungal resistance, mainly relates to their rapid degradation by proteolytic enzymes. The introduction of suitable structural changes in the peptide chain can make the peptide less susceptible to the action of proteases, thus overcoming this problem. To improve the plasma stability of calcitermin, a metal-chelating AMP present in the human respiratory tract and investigated in the present study, C- and/or N- terminal modifications have been introduced in the native sequence. Evaluation of peptide stability has been performed to determine the half-life times in human plasma of both native calcitermin and its derivatives. However, the protection of the peptide termini can also affect its metal coordination behaviour. Thus, the characterization of Zn2+ and Cu2+ complexes has been performed by means of several techniques, including potentiometry, high-resolution mass spectrometry, UV–Vis, circular dichroism and EPR. On the basis of the obtained results, it was possible to compare the biological activity of the studied systems, taking into account both the metal-binding ability and the peptide stability to search for a link among them. A significant result of this study is that the N-terminal protection increases the calcitermin half-life over seven times and the formation of metal complexes confers resistance towards degradation almost doubling its half-life.

SOLUNUM YOLU ÖRNEKLERİNDE İNSAN BOCAVİRUS'Ü SAPTANMASI

Objective: The aim of this study was to retrospectively examine the patients who presented with the complaints of respiratory tract infection and were found to have Human Bocavirus in the samples studied with the respiratory tract pathogens panel.
 Methods: We retrospectively analyzed patients of all age groups who were diagnosed with Human Bocavirus by PCR in the respiratory tract pathogens panel between January 2019 and November 2022.
 Results: Human Bocavirus was detected in 36 (3.64%) of 989 patients whose samples were studied with the respiratory tract pathogens panel. Fifteen of the patients (n:36) were under three years old. While Human Bocavirus was detected alone in 18 (50%) of the patients (n: 36), it was detected together with another factor in 18 (50%) patients.
 Conclusion: Human Bocavirus can be detected alone and/or as co-, infection in children with acute respiratory tract infection. The cause-effect relationship between Human Bocavirus and respiratory tract infection is not clearly known.

Particle size matters: Discrepancies in the health risks posed by traditional cigarettes and e-cigarettes in mice and humans

Electronic cigarettes (ECs), considered a healthier alternative to traditional cigarettes (TCs), vaporize e-liquid, which may produce harmful by-products due to thermal decomposition and metal transfer. These by-products' deposition in the respiratory tract is largely determined by particle size distribution (PSD). We employ the Multiple-Path Particle Dosimetry (MPPD) model to assess particle deposition within the human and mouse respiratory tracts. Leveraging the known connection between TC smoke inhalation and atherosclerosis, we used human aortic endothelial cells (HAECs) and ApoE-/- mice to explore the potential effects of EC aerosol inhalation on atherosclerosis. Our findings reveal that TCs exhibit a highly variable PSD, with mean diameters of approximately 300 nm for mainstream (MS) smoke and 120 nm for side stream (SS) smoke. Conversely, ECs demonstrate a more stable PSD. Combined with MPPD, the deposition fraction in the human respiratory system and mice is mainly deposited in the pulmonary region and head airway. For the Apoe-/- mice exposure experiment, preliminary findings suggest a potential impact on atherosclerosis, although not statistically significant, likely due to the limited sample size and exposure duration. This study highlights the importance of considering PSD, exposure dosage, and species-specific differences in risk assessments of EC aerosols.

Effect of Bronchial Blood Flow on Respiratory Heat Exchange: A Mathematical Analysis for Infectious Diseases

Abstract The present study aims to mathematically analyze the role of bronchial blood flow on heat transfer in respiratory infections. In general, the exchange of heat transfer in various infectious diseases like COVID-19 caused by SARS-CoV-2 has adversely affected respiration by reducing the physiological efficiency of the human respiratory tract. The mechanism of heat exchange through airway walls with the bronchial blood circulation still needs to be thoroughly studied for infectious diseases. In this article, a three-dimensional (3D) spatio-temporal theoretical model is developed to estimate the possible role of bronchial blood on heat exchange during breathing. The local description of the model is presented in a comprehensive and consistent dimensionless framework to explicitly state the actual physiological background. The global description is framed by a multicompartment-based approach, and the algorithm is solved using an advanced numerical scheme to ensure computational tractability. The numerical study elucidates the role of inhalation air temperature, breathing cycles, blood perfusion rate, and mucosal hydration. The outcomes of the algorithm estimate the parameters of the isothermal saturation boundary (ISB), which is defined as the position in the respiratory tract where the temperature of inhaled air comes in equilibrium with the body core saturation temperature. The derived results help to understand the pathophysiological threshold limits and recommend the values to evaluate respiratory distress. With the variations of inspiratory flow conditions, it is observed that the ISB position shifts to the distal branches with the increment in inhalation temperature, breathing rate and virus infection, and decrement in blood perfusion rate. The two antiparallel effects are observed: inhalation of cold air transmits the viral infection, and inhalation of warm air produces thermal injury. However, both can be well controlled by suitable ventilation rates. The observed threshold values may be helpful in clinical trials to correlate the anatomic configuration with pathophysiology.

Modified human respiratory tract model to describe the retention of plutonium in scar tissues.

The Human Respiratory Tract Model described in Publication 130 of the International Commission on Radiological Protection provides some mechanisms to account for retention of material that can be subject to little to no mechanical transport or absorption into the blood. One of these mechanisms is 'binding', which refers to a process by which a fraction ('bound fraction') of the dissolved material chemically binds to the tissue of the airway wall. The value of the bound fraction can have a significant impact on the radiation doses imparted to different parts of the respiratory tract. To properly evaluate-and quantify-bound fraction for an element, one would need information on long-term retention of the element in individual compartments of the respiratory tract. Such data on regional retention of plutonium in the respiratory tract of four workers-who had inhaled materials with solubility ranging from soluble nitrate to very insoluble high-fired oxides-were obtained at the United States Transuranium and Uranium Registries. An assumption of bound fraction alone was found to be inconsistent with this dataset and also with a review of the literature. Several studies show evidence of retention of a large amount of Pu activity in the scar tissues of humans and experimental animals, and accordingly, a model structure with scar-tissue compartments was proposed. The transfer rates to these compartments were determined using Markov Chain Monte Carlo analysis of the bioassay and post-mortem data, considering the uncertainties associated with deposition, dissolution and particle clearance parameters. The models predicted that a significant amount-between 20 and 100% for the cases analyzed-of plutonium retained in the respiratory tract was sequestered in the scar tissues. Unlike chemically-bound Pu that irradiates sensitive epithelial cells, Pu in scar tissues may not be dosimetrically significant because the scar tissues absorb most, if not all, of the energy from alpha emissions.

Study on airflow and particle transport in In silico human respiratory tract

Study on airflow and particle transport in In silico human respiratory tract

Treatment Outcomes of Mechanically Ventilated Patients with COVID-19 and Associated Factors among Hospitalized Patients at ICU of SPHMMC, Addis Ababa, Ethiopia

Introduction: Coronavirus (CoV) is derived from the word ‘corona’ meaning ‘crown’ in Latin. Coronavirus causes a range of human respiratory tract infections varying from mild cold to severe respiratory distress syndrome. Nowadays, due to the limited number of ICU beds and ventilators and the increasing number of patients with COVID-19 infection requiring MV data on patient characteristics, and outcomes of critical illness from COVID-19 are needed to inform decision-making about resource allocation, critical care capacity, and treatment of patients. Objectives: To assess outcomes and associated factors of patients with COVID-19 on mechanical ventilation at SPHMMC COVID ICU, Addis Ababa, Ethiopia, 2020 G.C. Methods: A single center cross-sectional study was used. All consecutive ICU admitted patients with RT-PCR confirmed COVID-19 and received mechanical ventilation support during the first 5 months were included. Data was collected from patient’s medical records using a structured questionnaire and the collected data was entered and analyzed using SPSS version 24. Results: A total of 104 ICU patients with COVID-19 were included. The majority, 73.1% were male; the median age was 60 (IQR; 45-70) years, with 36.5% patients having at least one chronic medical condition. Out of 165, 104(63%) patients needed mechanical ventilation. Invasive and noninvasive ventilation were used in 93(89.4%) and 11(10.6%) patients, respectively. The most common treatments used by the patients were steroid (100%), antibiotics (99%) and vaso-pressors (57.7%). Experimental antiviral therapy was used in only 1% (n=1) of patients. Overall the ICU mortality was 14.6% and 88.5% among mechanically ventilated patients. Being fatigue (AOR=7.599; 95% CI: 1.65-35.12), IMV (AOR=5.28; 95% CI: 1.01-27.71), and septic shock (AOR=12.83; 95% CI: 1.46-13.11) were a significant risk factors for the ICU outcomes of the patients. Conclusion: The study showed high proportion of mortality among ICU patients who received mechanical ventilator support with low rate of discharge. Male patients and old age groups with co-morbidity were disproportionately affected by the disease condition.

THE CONDITION OF MUCOCILIARY CLEARANCE IN PATIENTS WITH NASAL SEPTUM DEVIATION AND POSTNASAL DRIP SYNDROME

Introduction. Mucociliary clearance is a vital defense mechanism in the human upper respiratory tract that safeguards the body against inhaled harmful substances. Ciliary activity was first discovered by Sharpey in 1835, and it took nearly a century for this function to be recognized as a central component in the physiology of the sinuses.
 The aim of this study is to investigate the status of mucociliary clearance in patients with a nasal septum deviation and concomitant postnasal drip syndrome.
 Materials and Methods: A total of 54 patients, aged between 23 and 55 years, were enrolled in the study. All participants underwent a saccharin test and an assessment of the motor activity of the ciliated epithelium. Exclusion criteria included the presence of infectious and inflammatory diseases of the upper respiratory tract within the last month.
 Results: In the control group of patients, no significant difference was observed in the speed of saccharin test passage, both in the right and left parts of the nasal cavity, with test times ranging from 8.35 to 14.52 minutes. However, in the second clinical group comprising patients with nasal septum deviation, the average time for the saccharin test on the mucous membrane of the concave side of the nasal septum was significantly longer than on the convex side, measuring 21.52 ± 3.04 minutes and 12.36 ± 2.73 minutes, respectively (P = 0.02). When assessing the data from patients in the third clinical group based on the curvature side, a significant difference (P < 0.05) was observed in the reduction of saccharin test speed compared to the control group.
 Conclusions: The data obtained indicate a significant influence of nasal septum deviation on subsequent changes in nasal cavity physiology, resulting in a slowdown of mucociliary clearance. This can lead to excessive mucus stagnation in the nasal cavity and, consequently, the development of postnasal drip syndrome.