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1.
Eur J Pharm Biopharm ; 195: 114170, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38128743

ABSTRACT

Respiratory tract infections (RTIs) are one of the leading causes of death globally, lately exacerbated by the increasing prevalence of antimicrobial resistance. While antimicrobial resistance could be overcome by developing new antimicrobial agents, the use of a safe repurposed agent having potent antimicrobial activity against various RTIs can be an efficient and cost-effective alternative to overcome the long and complex process of developing and testing new drugs. Ebselen, a synthetic organoselenium drug originally developed to treat noise-inducing hearing problems, has shown promising antimicrobial activity in vitro against several respiratory pathogens including viruses (e.g., SARS-CoV-2, influenza A virus) and bacteria (e.g., Mycobacterium tuberculosis, Streptococcus pneumoniae, and Staphylococcus aureus). Inhaled drug delivery is considered a promising approach for treating RTIs, as it can ensure effective drug concentrations at a lower dose, thereby minimizing the side effects that are often encountered by using oral or injectable drugs. In this study, we developed inhalable ebselen dry powder formulations using a spray-drying technique. The amino acids leucine, methionine, and tryptophan were incorporated with ebselen to enhance the yield and aerosolization of the dry powders. The amino acid-containing ebselen dry powders showed a better yield (37-56.4 %) than the amino acid-free formulation (30.9 %). All dry powders were crystalline in nature. The mass median aerodynamic diameter (MMAD) was less than 5 µm for amino acids containing dry powders (3-4 µm) and slightly higher (5.4 µm) for amino acid free dry powder indicating their suitability for inhalation. The aerosol performance was higher when amino acids were used, and the leucine-containing ebselen dry powder showed the highest emitted dose (84 %) and fine particle fraction (68 %). All amino acid formulations had similar cytotoxicity as raw ebselen, tested in respiratory cell line (A549 cells), with half-maximal inhibitory concentrations (IC50) between 100 and 250 µg/mL. Raw ebselen and amino acid-containing dry powders showed similar potent antibacterial activity against the Gram-positive bacteria S. aureus and S. pneumoniae with minimum inhibitory concentrations of 0.31 µg/mL and 0.16 µg/mL, respectively. On the other hand, raw ebselen and the formulations showed limited antimicrobial activity against the Gram-negative pathogens Pseudomonas aeruginosa and Klebsiella pneumoniae. In summary, in this study we were able to develop amino-acid-containing inhalable dry powders of ebselen that could be used against different respiratory pathogens, especially Gram-positive bacteria, which could ensure more drug deposition in the respiratory tract, including the lungs. DPIs are generally used to treat lung (lower respiratory tract) diseases. However, DPIs can also be used to treat both upper and lower RTIs. The deposition of the dry powder in the respiratory tract is dependent on its physicochemical properties and this properties can be modulated to target the intended site of infection (upper and/or lower respiratory tract). Further studies will allow the development of similar formulations of individual and/or combination of antimicrobials that could be used to inhibit a number of respiratory pathogens.


Subject(s)
Anti-Infective Agents , Isoindoles , Organoselenium Compounds , Respiratory Tract Infections , Humans , Powders/chemistry , Leucine , Staphylococcus aureus , Drug Repositioning , Dry Powder Inhalers/methods , Respiratory Aerosols and Droplets , Administration, Inhalation , Respiratory Tract Infections/drug therapy , Anti-Infective Agents/therapeutic use , Particle Size
2.
Int J Pharm ; 645: 123411, 2023 Oct 15.
Article in English | MEDLINE | ID: mdl-37703955

ABSTRACT

The respiratory tract, as the first and most afflicted target of many viruses such as SARS-CoV-2, seems to be the logical choice for delivering antiviral agents against this and other respiratory viruses. A combination of remdesivir and disulfiram, targeting two different steps in the viral replication cycle, has showed synergistic activity against SARS-CoV-2 in-vitro. In this study, we have developed an inhalable dry powder containing a combination of remdesivir and disulfiram utilizing the spray-drying technique, with the final goal of delivering this drug combination to the respiratory tract. The prepared dry powders were spherical, and crystalline. The particle size was between 1 and 5 µm indicating their suitability for inhalation. The spray-dried combinational dry powder containing remdesivir and disulfiram (RDSD) showed a higher emitted dose (ED) of >88% than single dry powder of remdesivir (RSD) (∼72%) and disulfiram (DSD) (∼84%), with a fine particle fraction (FPF) of ∼55%. Addition of L-leucine to RDSD showed >60% FPF with a similar ED. The in vitro aerosolization was not significantly affected after the stability study conducted at different humidity conditions. Interestingly, the single (RSD and DSD) and combined (RDSD) spray-dried powders showed limited cellular toxicity (CC50 values from 39.4 to >100 µM), while maintaining their anti-SARS-CoV-2 in vitro (EC50 values from 4.43 to 6.63 µM). In a summary, a combinational dry powder formulation containing remdesivir and disulfiram suitable for inhalation was developed by spray-drying technique which showed high cell viability in the respiratory cell line (Calu-3 cells) retaining their anti-SARS-CoV-2 property. In the future, in vivo studies will test the ability of these formulations to inhibit SARS-CoV-2 which is essential for clinical translation.

3.
Pharmaceutics ; 15(9)2023 Aug 29.
Article in English | MEDLINE | ID: mdl-37765198

ABSTRACT

There is a continuous effort to develop efficient treatments for coronavirus disease 2019 (COVID-19) and other viral respiratory diseases. Among the different strategies, inhaled treatment is considered one of the most logical and efficient approaches to treating COVID-19, as the causative "SARS-CoV-2 virus RNA" predominantly infects the respiratory tract. COVID-19 treatments initially relied on repurposed drugs, with a few additional strategies developed during the last two years, and all of them are based on monotherapy. However, drug combinations have been found to be more effective than monotherapy in other viral diseases such as HIV, influenza, and hepatitis C virus. In the case of SARS-CoV-2 infection, in vitro studies have shown synergistic antiviral activity combining remdesivir with ebselen, an organoselenium compound. Therefore, these drug combinations could ensure better therapeutic outcomes than the individual agents. In this study, we developed a dry powder formulation containing remdesivir and ebselen using a spray-drying technique and used L-leucine as an aerosolization enhancer. The prepared dry powders were spherical and crystalline, with a mean particle size between 1 and 3 µm, indicating their suitability for inhalation. The emitted dose (ED) and fine particle fraction (FPF) of remdesivir- and ebselen-containing dry powders were ~80% and ~57% when prepared without L-leucine. The ED as well as the FPF significantly increased with values of >86% and >67%, respectively, when L-leucine was incorporated. More importantly, the single and combinational dry powder of remdesivir and ebselen showed minimal cytotoxicity (CC50 > 100 µM) in Calu-3 cells, retaining their anti-SARS-CoV-2 properties (EC50 2.77 to 18.64 µM). In summary, we developed an inhalable dry powder combination of remdesivir and ebselen using a spray-drying technique. The spray-dried inhalable microparticles retained their limited cytotoxicity and specific antiviral properties. Future in vivo studies are needed to verify the potential use of these remdesivir/ebselen combinational spray-dried inhalable microparticles to block the SARS-CoV-2 replication in the respiratory tract.

4.
Phys Rev Lett ; 131(5): 057101, 2023 Aug 04.
Article in English | MEDLINE | ID: mdl-37595211

ABSTRACT

Information engines can convert thermal fluctuations of a bath at temperature T into work at rates of order k_{B}T per relaxation time of the system. We show experimentally that such engines, when in contact with a bath that is out of equilibrium, can extract much more work. We place a heavy, micron-scale bead in a harmonic potential that ratchets up to capture favorable fluctuations. Adding a fluctuating electric field increases work extraction up to ten times, limited only by the strength of the applied field. Our results connect Maxwell's demon with energy harvesting and demonstrate that information engines in nonequilibrium baths can greatly outperform conventional engines.

5.
Phys Rev Lett ; 129(13): 130601, 2022 Sep 23.
Article in English | MEDLINE | ID: mdl-36206430

ABSTRACT

We have experimentally realized an information engine consisting of an optically trapped, heavy bead in water. The device raises the trap center after a favorable "up" thermal fluctuation, thereby increasing the bead's average gravitational potential energy. In the presence of measurement noise, poor feedback decisions degrade its performance; below a critical signal-to-noise ratio, the engine shows a phase transition and cannot store any gravitational energy. However, using Bayesian estimates of the bead's position to make feedback decisions can extract gravitational energy at all measurement noise strengths and has maximum performance benefit at the critical signal-to-noise ratio.

6.
Pharmaceutics ; 14(7)2022 Jul 08.
Article in English | MEDLINE | ID: mdl-35890327

ABSTRACT

SARS-CoV-2, the causative agent of COVID-19, predominantly affects the respiratory tract. As a consequence, it seems intuitive to develop antiviral agents capable of targeting the virus right on its main anatomical site of replication. Ivermectin, a U.S. FDA-approved anti-parasitic drug, was originally shown to inhibit SARS-CoV-2 replication in vitro, albeit at relatively high concentrations, which is difficult to achieve in the lung. In this study, we tested the spray-drying conditions to develop an inhalable dry powder formulation that could ensure sufficient antiviral drug concentrations, which are difficult to achieve in the lungs based on the oral dosage used in clinical trials. Here, by using ivermectin as a proof-of-concept, we evaluated spray-drying conditions that could lead to the development of antivirals in an inhalable dry powder formulation, which could then be used to ensure sufficient drug concentrations in the lung. Thus, we used ivermectin in proof-of-principle experiments to evaluate our system, including physical characterization and in vitro aerosolization of prepared dry powder. The ivermectin dry powder was prepared with a mini spray-dryer (Buchi B-290), using a 23 factorial design and manipulating spray-drying conditions such as feed concentration (0.2% w/v and 0.8% w/v), inlet temperature (80 °C and 100 °C) and presence/absence of L-leucine (0% and 10%). The prepared dry powder was in the size range of 1−5 µm and amorphous in nature with wrinkle morphology. We observed a higher fine particle fraction (82.5 ± 1.4%) in high feed concentration (0.8% w/v), high inlet temperature (100 °C) and the presence of L-leucine (10% w/w). The stability study conducted for 28 days confirmed that the spray-dried powder was stable at 25 ± 2 °C/<15% RH and 25 ± 2 °C/ 53% RH. Interestingly, the ivermectin dry powder formulation inhibited SARS-CoV-2 replication in vitro with a potency similar to ivermectin solution (EC50 values of 15.8 µM and 14.1 µM, respectively), with a comparable cell toxicity profile in Calu-3 cells. In summary, we were able to manipulate the spray-drying conditions to develop an effective ivermectin inhalable dry powder. Ongoing studies based on this system will allow the development of novel formulations based on single or combinations of drugs that could be used to inhibit SARS-CoV-2 replication in the respiratory tract.

7.
J Appl Microbiol ; 133(4): 2668-2677, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35882427

ABSTRACT

AIMS: The RT-PCR is the most popular confirmatory test for SARS-CoV-2. It is sensitive, but high instrumentation cost makes it difficult for use outside routine clinical setup. This has necessitated the development of alternative methods such as CRISPR-based DETECTR method which uses lateral flow technology. Although accurate and sensitive, this method is limited by complex steps and recurrent cost of high-quality lateral flow strips. The main goal of this study was to improve the Cas12a-based SARS-CoV-2 DETECTR method and develop a portable and field-deployable system to reduce the recurring consumable cost. METHODS AND RESULTS: Specific regions of N and E genes from SARS-CoV-2 virus and human RNase P (internal control) were reverse transcribed (RT) and amplified by loop-mediated isothermal amplification (LAMP). The amplified products were detected by a Cas12a-based trans-cleavage reaction that generated a fluorescent signal which could be easily visualized by naked eye. Detection of internal control, RNase P gene was improved and optimized by redesigning RT-LAMP primers. A number of steps were reduced by combining the reagents related to the detection of Cas12a trans-cleavage reaction into a single ready-to-use mix. A portable, cost-effective battery-operated instrument, CRISPR-CUBE was developed to run the assay and visualize the outcome. The method and instrument were validated using both contrived and patient samples. CONCLUSIONS: The simplified CRISPR-based SARS-CoV-2 detection and instrument developed in this study, along with improved design for internal control detection allows for easier, more definitive viral detection requiring only reagents, consumables and the battery operable CRISPR-CUBE. SIGNIFICANCE AND IMPACT OF STUDY: Significant improvement in Cas12 method, coupled with simple visualization of end point makes the method and instrument deployable at the point-of-care (POC) for SARS-CoV-2 detection, without any recurrent cost for the lateral flow strips which is used in other POC methods.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , CRISPR-Cas Systems , Humans , Nucleic Acid Amplification Techniques/methods , Ribonuclease P/genetics , SARS-CoV-2/genetics
8.
Int J Pharm ; 624: 122042, 2022 Aug 25.
Article in English | MEDLINE | ID: mdl-35868481

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent responsible for the COVID-19 pandemic, has outspread at full tilt across the world. Although several effective vaccines continue to be deployed, reliable antiviral treatments have yet to be developed against this disease. Currently, available therapeutics for COVID-19 include repurposed, and a few novel drugs. Many drugs have been promising in preclinical studies, but a majority of these drugs have shown little or no efficacy in clinical studies. One of the major reasons is the insufficient drug concentration in the lung, the primary target site of infection for SARS-CoV-2, from the administration of drugs through oral or intravenous routes. Higher effective doses administered through these routes could also lead to adverse side effects. For this reason, inhaled treatments are being tested as an efficient approach for COVID-19, allowing lower doses of drugs ensuring higher concentrations of the drug(s) in the lung. The inhaled treatment combining two or more antiviral drugs will increase potency and reduce the possibility of selecting for SARS-CoV-2 variants with reduced drug susceptibility. Finally, the appropriate drug combination needs to be delivered using a suitable system. Here, we review the current treatment for COVID-19 and their limitations, discussing the advantages of mono and combinational inhaled therapy with a brief outline of the recently reformulated anti-SARS-CoV-2 agents as inhaled formulations. The selection of appropriate delivery devices for inhalation and associated key considerations including the formulation challenges are also discussed.


Subject(s)
COVID-19 Drug Treatment , SARS-CoV-2 , Antiviral Agents/therapeutic use , Humans , Pandemics , Pharmaceutical Preparations
9.
Germs ; 11(3): 408-417, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34722363

ABSTRACT

During the COVID-19 pandemic, the use of alcohol-based hand sanitizers (ABHS) increased worldwide among the public as well as the health care workers in pursuit to prevent the spread of SARS-CoV-2, the causative virus of COVID-19. Hand hygiene is one of the primary preventive measures to prevent the spread of harmful germs. Although ABHS are effective hand hygiene products and help reduce the transmission of pathogenic microorganisms, appropriate use of such products is necessary to ensure the maximum killing of pathogens and to prevent hazards associated with ABHS. The effectiveness of ABHS against different microorganisms, including SARS-CoV-2 is also documented, but proper knowledge on hand hygiene techniques, selection of appropriate hand sanitizer product, and safe handling of ABHS are required to avoid their adverse effects such as allergies, skin irritation, lung injury, fire hazards, and toxicities. The effectiveness of ABHS is dependent on several factors including its appropriate usage, manufacturing methods, the choice of active agents, and the appropriateness of the agent on the target pathogen. This article highlights the importance of proper usage, handling, and appropriate ABHS selection for maximum efficacy against intended pathogens and safe use of ABHS. User awareness can help promote the appropriate usage of ABHS and prevent its hazards, which ultimately can help in preventing the transmission of pathogenic microorganisms.

10.
Proc Natl Acad Sci U S A ; 118(20)2021 May 18.
Article in English | MEDLINE | ID: mdl-33972432

ABSTRACT

Information-driven engines that rectify thermal fluctuations are a modern realization of the Maxwell-demon thought experiment. We introduce a simple design based on a heavy colloidal particle, held by an optical trap and immersed in water. Using a carefully designed feedback loop, our experimental realization of an "information ratchet" takes advantage of favorable "up" fluctuations to lift a weight against gravity, storing potential energy without doing external work. By optimizing the ratchet design for performance via a simple theory, we find that the rate of work storage and velocity of directed motion are limited only by the physical parameters of the engine: the size of the particle, stiffness of the ratchet spring, friction produced by the motion, and temperature of the surrounding medium. Notably, because performance saturates with increasing frequency of observations, the measurement process is not a limiting factor. The extracted power and velocity are at least an order of magnitude higher than in previously reported engines.

11.
Rapid Commun Mass Spectrom ; 35(3): e8963, 2021 Feb 15.
Article in English | MEDLINE | ID: mdl-33002258

ABSTRACT

RATIONALE: A new compact thermal ionization (TI) mass spectrometer, for the isotope ratio analysis of the elements relevant to nuclear applications, has been designed and developed. The new development offers superior performance in terms of sensitivity, precision and a compact footprint in comparison with the conventional one. The main feature of the TI mass spectrometer is the magnetic sector analyser with a sector radius of 20 cm (instead of 30/27 cm in conventional/commercial geometry). An apparent reduction in dispersion has been adequately compensated by employing variable dispersion zoom optics (VDZO). METHODS: The theoretical calculations were validated by computer simulations using SIMION 7.0, leading to the finalization of the mechanical design. Experimental evaluation was carried out using standard TI mass spectrometric methodology to determine the parameters, namely peak flatness, mass range, sensitivity, abundance sensitivity, resolution and precision. RESULTS: The multi-collector resolution was 496, and the maximum mass was m/z 382. The sensitivity for uranium was found to be better than 1 ion for 500 atoms, and an abundance sensitivity of 50 ppm at m/z 237 was obtained. The peak flatness for the uranium peak was 3200 ppm of mass. The precision for the isotopic ratio 235 U/238 U was found to be 0.05% for the U200 standard. CONCLUSIONS: A new compact TI mass spectrometer with a 20 cm sector radius has been designed and developed. The advantage of larger dispersion produced by the VDZO (developed in-house) was exploited when deciding the 20 cm sector radius. The comparison study with the conventional TI mass spectrometer shows an enhanced (1.5×) sensitivity and an improved precision (0.05%) for the 235 U/238 U ratio of U200.

12.
J. Health Biol. Sci. (Online) ; 9(1): 1-7, 2021. ilus, tab
Article in English | LILACS | ID: biblio-1370070

ABSTRACT

Objectives: This study aimed to explore the prevalence and severity of COVID-19 disease in SAARC affiliated countries and show the comparison by analyzing the patterns of infections, recoveries, and deaths among the countries. Methods: The data related to COVID-19 of SAARC affiliated countries were collected from Worldometer in which the dataset consists of daily confirmed, recovery, and death cases. To compare the prevalence and severity of COVID-19 among these countries, we consider three parameters such as case fatality rate (CFR), recovery-to-death ratio (RDR), and percent active case (PAC). Results: The highest daily CFR among the SAARC affiliated countries was in Bangladesh followed by Afghanistan, India, Sri Lanka, Pakistan, Nepal and the Maldives according to the maximum CFR of the countries until 24 October 2020. The highest RDR among the SAARC affiliated countries was in Nepal followed by the Maldives, Sri Lanka, India, Bangladesh, Pakistan, Afghanistan until 24 October. The most prevalent country according to infection per million people by COVID-19 among the SAARC affiliated countries is the Maldives followed by India, Nepal, Bangladesh, Pakistan, Afghanistan, Bhutan, and Sri Lanka as of October 24. The most death prevalent country per million people is India followed by the Maldives, Afghanistan, Bangladesh, Pakistan, Nepal, Sri Lanka, and no people died in Bhutan until October 24, 2020. Conclusion: This study shows that the severity of COVID-19 is high in the Maldives in terms of infections and India in terms of deaths per million in SAARC, so India is at high risk among the countries.


Objetivos: Este estudo teve como objetivo explorar a prevalência e gravidade da doença COVID-19 em países afiliados à SAARC e mostrar a comparação por meio da análise dos padrões de infecções, recuperações e mortes entre os países. Métodos: Os dados relacionados ao COVID-19 dos países afiliados à SAARC foram coletados do worldometer no qual o conjunto de dados consiste em casos diários confirmados, de recuperação e de óbito. Para comparar a prevalência e gravidade de COVID-19 entre esses países, consideramos três parâmetros, como taxa de letalidade (CFR), razão de recuperação para óbito (RDR) e porcentagem de casos ativos (PAC). Resultados: O CFR diário mais alto entre os países afiliados da SAARC foi em Bangladesh, seguido pelo Afeganistão, Índia, Sri Lanka, Paquistão, Nepal, Maldivas, de acordo com o CFR máximo dos países até 24 de outubro de 2020. O RDR mais alto entre os países afiliados da SAARC foi no Nepal, seguido por Maldivas, Sri Lanka, Índia, Bangladesh, Paquistão, Afeganistão até 24 de outubro. O país mais prevalente, de acordo com a infecção por milhão de pessoas por COVID-19 entre os países afiliados à SAARC, é as Maldivas, seguido pela Índia, Nepal, Bangladesh, Paquistão, Afeganistão, Butão e Sri Lanka em 24 de outubro. País com maior prevalência de morte em por milhão de pessoas é a Índia, seguida por Maldivas, Afeganistão, Bangladesh, Paquistão, Nepal, Sri Lanka, e nenhuma pessoa morreu no Butão até 24 de outubro de 2020. Conclusão: Este estudo mostra que a gravidade do COVID-19 é alta nas Maldivas em termos de infecções e na Índia, em termos de mortes por milhão na SAARC. Portanto, a Índia está em alto risco entre os países.


Subject(s)
COVID-19 , Mortality , Death , Pandemics , Infections
13.
J. Health Biol. Sci. (Online) ; 8(1): 1-7, 20200101. ilus
Article in English | LILACS | ID: biblio-1129916

ABSTRACT

Objectives: This study aimed to reveal the prevalence of COVID-19 and investigate the patterns of deaths due to novel coronavirus in Bangladesh. Methods: The data about daily incidences, sex and deaths by the geography of COVID-19 for Bangladesh as of August 29, 2020 have been collected from the daily press releases of the Institute of Epidemiology, Disease Control and Research (IEDCR) and Directorate General of Health Services (DGHS). Case fatality rates (CFR), doubling time, correlation coefficient and graphical presentation were used to investigate the prevalence and patterns of infection and deaths. Results: Infection to tests, recovery to infections and death to infection rates due to novel coronavirus in Bangladesh until August 29, 2020 was 20.25%, 64.37% and 1.36% respectively. The correlation coefficient between daily tests and infections has found 0.978 with a 95% confidence interval 0.971 to 0.984. About 78.46% male and only 21.54% of females have died. Most deaths were found in the Dhaka division (48.26%) and the least deaths in the Mymensingh division (2.12%). The sex ratio of males to females in deaths was 364.23%. The age below 10 has found the least prevalent (0.45%) to deaths and above 60 has found most vulnerable (49.26%) to death. Conclusions: This study showed a strong positive relationship between daily tests and infections. The doubling time of infections and deaths in Bangladesh increased over time maintaining very low differences. Male people are more vulnerable to death compare to females. Aged people are extremely vulnerable to death. The most deaths geographical division is Dhaka and the least deaths in Mymensingh.


Objetivos: o objetivo deste estudo foi revelar a prevalência de COVID-19 e investigar os padrões de mortes por novos coronavírus em Bangladesh. Métodos: os dados sobre incidências diárias, sexo e mortes por geografia de COVID-19 para Bangladesh em 29 de agosto de 2020 foram coletados dos comunicados de imprensa diários do Instituto de Epidemiologia, Controle e Pesquisa de Doenças (IEDCR) e da Diretoria Geral de Serviços de Saúde (DGHS). As taxas de letalidade (CFR), o tempo de duplicação, o coeficiente de correlação e a apresentação gráfica foram usados para investigar a prevalência e os padrões de infecção e mortes. Resultados: as taxas de infecção para testes, recuperação de infecções e morte por infecção devido a novo coronavírus em Bangladesh até 29 de agosto de 2020 foram de 20,25%, 64,37% e 1,36%, respectivamente. O coeficiente de correlação entre os testes diários e infecções encontrou 0,978 com intervalo de confiança de 95% 0,971 a 0,984. Cerca de 78,46% homens e apenas 21,54% mulheres morreram. A maioria das mortes foi encontrada na divisão de Dhaka (48,26%) e menos mortes na divisão Mymensingh (2,12%). A proporção do sexo entre homens e mulheres nas mortes foi de 364,23%. A faixa etária abaixo de 10 apresentou menor prevalência (0,45%) aos óbitos e acima de 60 foi considerada mais vulnerável (49,26%) ao óbito. Conclusões: este estudo mostrou uma forte relação positiva entre testes diários e infecções. O tempo de duplicação de infecções e mortes em Bangladesh aumentou com o tempo, mantendo diferenças muito baixas. Os homens são mais vulneráveis à morte do que as mulheres. Pessoas idosas são extremamente vulneráveis à morte. A divisão geográfica com mais mortes é Dhaka e menos mortes é Mymensingh.


Subject(s)
Coronavirus Infections , Coronavirus , Reference Standards , Bangladesh , Women , Disease , Epidemiology , Incidence , Mortality , Infections , Men
14.
Opt Lett ; 41(18): 4356-9, 2016 Sep 15.
Article in English | MEDLINE | ID: mdl-27628396

ABSTRACT

We trap absorbing micro-particles in air by photophoretic forces generated using a single loosely focused Gaussian trapping beam. We measure a component of the radial Brownian motion of a trapped particle cluster and determine the power spectral density, mean squared displacement, and normalized position and velocity autocorrelation functions to characterize the photophoretic body force in a quantitative fashion for the first time. The trapped particles also undergo spontaneous rotation due to the action of this force. This is evident from the spectral density that displays clear peaks at the rotation and the particles' inertial resonance frequencies. We fit the spectral density to the well-known analytical function derived from the Langevin equation, measure the resonance and rotation frequencies, and determine the values for particle mass that we verify at different trapping laser powers with reasonable accuracy.

15.
Diagn Microbiol Infect Dis ; 76(1): 5-9, 2013 May.
Article in English | MEDLINE | ID: mdl-23420012

ABSTRACT

Currently, no reliable diagnostic test is available for typhoid fever. One serology-based dipstick test, developed indigenously, was validated in this study. Preserved sera from 336 fever patients with known culture results for Salmonella Typhi were blindly tested by the Widal test and the new assay. Analytical sensitivities, specificities, and efficiencies for the new assay versus the Widal test were 68.8% versus 62.5%, 71.1% versus 37.1%, and 70.5% versus 43.2%, respectively (p < 0.001), considering S. Typhi-positive samples as gold standards. Thereafter, fresh sera from 102 hospital-attending children with clinical typhoid fever (including 20 confirmed nontyphoidal cases as control) were tested by both methods and analyzed statistically. The diagnostic sensitivity, specificity, and efficiency were 51.2%, 85%, and 57.8% for the new assay, and 43.9%, 65%, and 48% for the Widal test, respectively. Overall performance ability of the new assay was not better than the Widal test (p > 0.5). Further improvement of the new point-of-care typhoid assay is recommended before implementation in the field setup.


Subject(s)
Serologic Tests/methods , Typhoid Fever/diagnosis , Agglutination Tests/methods , Antibodies, Bacterial/blood , Antigens, Bacterial/blood , Case-Control Studies , Child , Child, Preschool , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , India , Salmonella/isolation & purification , Salmonella typhi/isolation & purification , Sensitivity and Specificity , Typhoid Fever/blood
16.
Trop Med Int Health ; 16(5): 555-61, 2011 May.
Article in English | MEDLINE | ID: mdl-21332891

ABSTRACT

OBJECTIVE: To assess the clinical efficacy of Lactobacillus sporogenes (Bacillus coagulans), as probiotic preparation, against dehydrating diarrhoea in children. METHODS: Double-blind, randomised, placebo-controlled, hospital-based clinical trial with children aged 6-24 months who had diarrhoea with some dehydration. Children received tablets of L. sporogenes (B. coagulans) or placebo (control group) and oral rehydration salt solution for correction of initial dehydration as well as maintenance therapy. Duration, frequency, volume of diarrhoea and intake of ORS of two groups were compared as outcome variables. RESULTS: One hundred and forty-eight children participated, of whom 78 (Study group) received L. sporogenes (B. coagulans) and 70 received placebo (Control group). Differences in recovery rate (P=0.2), duration (P=0.5), frequency (P=0.05), volume (P=0.1) of diarrhoea, intake of ORS (P=0.2) and other fluids (P=0.1) were not significant between both groups. Neither did a subgroup analysis of children who had rotavirus as sole enteropathogens show any significant differences in duration (P=0.5), frequency (P=0.6), volume (P=0.8) of diarrhoea, intake of ORS (P=0.8) and other fluids (P=0.8) among both groups. CONCLUSION: L. sporogenes (B. coagulans), as an adjunct to ORS, had no therapeutic impact on management of acute dehydrating diarrhoea of diverse etiology including rotavirus associated diarrhoea in children.


Subject(s)
Diarrhea, Infantile/therapy , Lactobacillus , Probiotics/therapeutic use , Acute Disease , Dehydration/etiology , Diarrhea, Infantile/complications , Diarrhea, Infantile/microbiology , Double-Blind Method , Humans , Infant , Male , Rotavirus Infections/therapy , Treatment Outcome
17.
Indian J Community Med ; 35(2): 276-9, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20922106

ABSTRACT

OBJECTIVES: To find out the magnitude of malnutrition among the adolescents of an urban slum of Kolkata study population. To compare the middle upper arm circumference (MUAC) with that of body mass index (BMI) for determination of nutritional status of the study population. MATERIALS AND METHODS: This was a school-based descriptive epidemiological study done among adolescent male students aged 10-19 years in the service area of Urban Health Centre, Chetla. The school is an all boy's government aided school and all the students reside in the Chetla slum, the largest slum of Kolkata. Anthropometric measurements of the students of one section selected from each class i.e. class V to XII were recorded. RESULTS: Results showed 47.93% of study population as per BMI and 60.30% as per MUAC were malnourished. Evaluation of screening test showed MUAC as a marker was 94.6% sensitive and 71.2% specific. A correlation between measurements of MUAC and BMI was demonstrated (r=0.822; SE=0.035; 95% CI; P=0.000000; r(2)=0.74).

19.
J Clin Virol ; 45(3): 223-9, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19464942

ABSTRACT

BACKGROUND: Noroviruses (NoVs) are one of the major causal agents of acute gastroenteritis among different age groups. Some of the recent studies reveal that NoV genome is highly prone to mutation and recombination which often leads to emergence of new strains. OBJECTIVES: To explore the genetic diversity of human Caliciviruses (HuCVs) among diarrhoeic children in Kolkata. STUDY DESIGN: The HuCVs were detected by reverse transcription-polymerase chain reaction (RT-PCR) of the partial RNA dependent RNA polymerase gene (RdRp) and capsid gene and confirmed by sequencing. The sequences were analyzed and the recombination point was detected. RESULTS: Faecal specimens of children (n=111) visiting outpatient department of Dr B. C. Roy Memorial Hospital for Children with acute gastroenteritis were studied: 22 cases were HuCV positive with 21 NoVs. Of these, 12 NoV cases (54.5%) were GII.4 and six cases showed 99% identity with the new variant Japanese strain Hu/NoV/GII.4/OC07138/JP. Three novel NoV GII inter-genotype recombinant strains V1628/IND, V1656/IND and V1737/IND were also detected. The RdRp region of V1628 showed 96% identity with Pont de Roide 673/FRN whereas capsid region resembled GII.7/Osaka F140/JPN strain (98%); the strain V1656 showed 98% identity with RdRp region of GII.4/Monastir 375/TUN but capsid region resembled GII.8/Leverkusen 267/DE (91%); the strain V1737 showed 88% identity with RdRp of GII.5/Minato 6/N1/6/JPN whereas capsid region resembled the GII.12/Gifu 96/JPN (93%). During characterization of Caliciviruses two strains of NoV GII.b and one strain of each NoV GI.1/V1622/06/IND, GI.3/V1707/07/IND, GII.3/V1668/IND, GII.16/V1729/IND, Sapovirus GII.1/V1716/IND were also detected. CONCLUSIONS: The emergence of new variant of GII.4/2007, three novel NoV GII inter-genotype recombinant strains and various other NoVs, indicates the remarkable genetic diversity of the HuCVs as diarrhoeagenic viruses circulating in Kolkata, India.


Subject(s)
Caliciviridae Infections/virology , Diarrhea/virology , Gastroenteritis/virology , Norovirus/classification , Norovirus/isolation & purification , Recombination, Genetic , Caliciviridae Infections/epidemiology , Child, Preschool , Cluster Analysis , Diarrhea/epidemiology , Feces/virology , Gastroenteritis/epidemiology , Genetic Variation , Genotype , Humans , India/epidemiology , Infant , Molecular Sequence Data , Norovirus/genetics , Phylogeny , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Homology
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