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Biomedical subjects

Rajesh Pandey

Publications and source records attributed to Rajesh Pandey.

At least 19 recordsLinked to original sources
PubMed2024

Protocol to decode the role of transcriptionally active microbes in SARS-CoV-2-positive patients using an RNA-seq-based approach.

The elucidation of the role of microorganisms in human infections has been hindered by difficulties using conventional culture-based techniques. Here, we present a protocol for the investigation of transcriptionally active microbes (TAMs) using an RNA sequencing (RNA-seq)-based approach. We describe the steps for RNA isolation, viral genome sequencing, RNA-seq library preparation, and metatranscriptomic and transcriptomic analysis. This protocol permits a comprehensive evaluation of TAMs' contributions to the differential severity of infectious diseases, with a particular focus on diseases such as COVID-19. For complete details on the use and execution of this protocol, please refer to Devi et al.1.

Humans↗
PubMed2024

RNA editing in host lncRNAs as potential modulator in SARS-CoV-2 variants-host immune response dynamics.

Both host and viral RNA editing plays a crucial role in host's response to infection, yet our understanding of host RNA editing remains limited. In this study of in-house generated RNA sequencing (RNA-seq) data of 211 hospitalized COVID-19 patients with PreVOC, Delta, and Omicron variants, we observed a significant differential editing frequency and patterns in long non-coding RNAs (lncRNAs), with Delta group displaying lower RNA editing compared to PreVOC/Omicron patients. Notably, multiple transcripts of UGDH-AS1 and NEAT1 exhibited high editing frequencies. Expression of ADAR1/APOBEC3A/APOBEC3G and differential abundance of repeats were possible modulators of differential editing across patient groups. We observed a shift in crucial infection-related pathways wherein the pathways were downregulated in Delta compared to PreVOC and Omicron. Our genomics-based evidence suggests that lncRNA editing influences stability, miRNA binding, and expression of both lncRNA and target genes. Overall, the study highlights the role of lncRNAs and how editing within host lncRNAs modulates the disease severity.

Biological sciences↗
PubMed2006

Pharmacokinetic and pharmacodynamic behaviour of antitubercular drugs encapsulated in alginate nanoparticles at two doses.

This study was designed to evaluate the pharmacokinetics and tissue distribution of free and alginate-encapsulated antitubercular drugs in mice at different doses. Alginate nanoparticles encapsulating isoniazid (INH), rifampicin (RIF), pyrazinamide (PZA) and ethambutol (EMB) were prepared by controlled cation-induced gelification of alginate. The formulation was orally administered to mice at two dose levels (D1 and D2). A comparison was made in mice receiving free drugs at equivalent doses. Drugs were analysed by high performance liquid chromatography (HPLC). The average size of alginate nanoparticles was found to be 235.5+/-0.0 nm with a polydispersity index of 0.44; drug encapsulation was 70-90% for INH and PZA, 80-90% for RIF and 88-95% for EMB. In the free drug groups, plasma levels of RIF and INH were higher and PZA and EMB levels were lower in the D1 group (per body surface area of mice) compared with the D2 group (recommended human dose). The plasma drug levels of all drugs were higher in the D1 encapsulated group compared with D2, resulting in higher values of area under the plasma drug concentration-time curve (AUC(0-infinity)). The relative bioavailabilities of all drugs encapsulated in alginate nanoparticles were significantly higher compared with free drugs. Drug levels were maintained at or above the minimum inhibitory concentration (MIC(90)) until Day 15 in organs after administration of encapsulated drugs, whilst free drugs stayed at or above the MIC(90) up to Day 1 only irrespective of dose. The levels of drugs in various organs remained above the MIC at both doses for equal periods, demonstrating their equiefficiency. Alginate nanoparticles hold great potential in reducing dosing frequency of antitubercular drugs.

Alginates↗
PubMed2006

Oral nanoparticle-based antituberculosis drug delivery to the brain in an experimental model.

OBJECTIVES: To evaluate the potential of orally administered poly-lactide-co-glycolide (PLG, a synthetic polymer) nanoparticle encapsulated antituberculosis drugs (ATDs) (rifampicin + isoniazid + pyrazinamide + ethambutol) for cerebral drug delivery in a murine model. METHODS: The formulation was prepared using the multiple emulsion technique and administered orally to mice for biodistribution, pharmacokinetic and chemotherapeutic studies. RESULTS: A single oral dose of the formulation to mice could maintain sustained drug levels for 5-8 days in the plasma and for 9 days in the brain. There was a significant improvement in the pharmacokinetic parameters such as mean residence time and relative bioavailability as compared with free drugs. The pharmacodynamic parameters such as the ratio of area under the curve to minimum inhibitory concentration (AUC/MIC) and the time up to which MIC levels were maintained in plasma (T(MIC)) were also improved. In Mycobacterium tuberculosis H(37)Rv infected mice, five oral doses of the nanoparticle formulation administered every 10th day resulted in undetectable bacilli in the meninges, as assessed on the basis of cfu and histopathology. CONCLUSIONS: Polymeric nanoparticles bear significant potential for ATD delivery to the brain.

Administration, Oral↗
PubMed2006

A mixture of organophosphate and pyrethroid intoxication requiring intensive care unit admission: a diagnostic dilemma and therapeutic approach.

The illegal mixing of organophosphates and pyrethroids in marketed agriculture insecticides is becoming prevalent in developing countries. Over a 12-mo period, 8 patients were admitted to the emergency department of a university hospital in Dharan, Nepal after ingestion of such a mixture with suicidal intent. All patients presented with a combination of miosis, bradycardia, tachypnea, and unconsciousness. The occurrence of both pupillary dilation after a small-dose infusion of atropine (0.08 to 0.2 mg/kg in 1-3 h) and seizures raised the possibility of pyrethroid poisoning. In each case, an examination of the insecticide container confirmed that it contained a mixture of organophosphate and pyrethroid. After seizure control, gastric lavage, respiratory support, hemodynamic stabilization and diuresis, seven of the patients recovered without neurological deficit. One patient suffered aspiration pneumonia and died. The early clinical picture after this mixed poisoning is based on the toxicity of organophosphates rather than pyrethroids. Because the patients responded to a small dose of atropine with mydriasis and tachycardia, it suggested a mixed poisoning. Early suspicion of mixed poisoning may have a significant prognostic impact.

Adult↗
PubMed2006

Scorpion sting envenomation presenting with pulmonary edema in adults: a report of seven cases from Nepal.

Scorpion sting is a common problem in villages of Eastern Nepal. The life-threatening complications of myocarditis and pulmonary edema is known in red scorpion in India but not reported in Nepal. This condition requires urgent attention and ICU care from few hours to days. Delay in recognition and the hypoxemia increase the morbidity and mortality. Illiteracy, ignorance, poverty, traditional faith healers trying treatment in remote areas, lack of transport in difficult terrains and the non availability of ventilation facility in nearby hospital, add to delay in appropriate treatment. Seven young adult patients admitted in a span of two years with history of scorpion sting presenting with pulmonary edema required ICU care. They were successfully managed with the positive pressure ventilation with PEEP, cardiac support with inotropes and fluid balance. Magnitude of problem, clinical presentation and management done is emphasized.

Adolescent↗
PubMed2006

Nanotechnology based drug delivery system(s) for the management of tuberculosis.

The era of nanotechnology has allowed new research strategies to flourish in the field of drug delivery. Nanoparticle-based drug delivery systems are suitable for targeting chronic intracellular infections such as tuberculosis. Polymeric nanoparticles employing poly lactide-co-glycolide have shown promise as far as intermittent chemotherapy in experimental tuberculosis is concerned. It has distinct advantages over the more traditional drug carriers, i.e. liposomes and microparticles. Although the experience with natural carriers, e.g. solid lipid nanoparticles and alginate nanoparticles is in its infancy, future research may rely heavily on these carrier systems. Given the options for oral as well as parenteral therapy, the very nature of the disease and its complex treatment urges one to emphasize on the oral route for controlled drug delivery. Pending the discovery of more potent antitubercular drugs, nanotechnology-based intermittent chemotherapy provides a novel and sound platform for an onslaught against tuberculosis.

Animals↗
PubMed2006

Oral poly(lactide-co-glycolide) nanoparticle based antituberculosis drug delivery: toxicological and chemotherapeutic implications.

The present study reports on the detailed toxicological and chemotherapeutic evaluation of antituberculosis drug loaded nanoparticles in mice. A single oral dose administration of poly(lactide-co-glycolide) (PLG, a synthetic polymer) nanoparticles containing rifampicin+isoniazid+pyrazinamide+ethambutol could maintain drug levels in various tissues for 9-10 days and did not elicit any adverse response even when administered at several fold higher than the recommended therapeutic dose. However, dosing with conventional free drugs at the equivalent higher doses was lethal. Despite multiple oral dosing with the formulation at every 10th day, no toxicity was observed on the completion of subacute (28 days) or chronic (90 days) toxicity studies based on survival, gross pathology, histopathology, blood biochemistry and hematology. In mice harboring a high mycobacterial load (mimicking human tuberculosis), two independent chemotherapeutic regimens, i.e. 5 doses of PLG nanoparticles encapsulating (rifampicin+isoniazid+pyrazinamide+ethambutol) administered 10 days apart, or 2 doses of the 4-drug formulation followed by 3 doses of 2-drug formulation (rifampicin+isoniazid) resulted in undetectable bacilli. Further, the efficacy was comparable to 46 daily doses of oral free drugs. Therefore, the experimental evidence suggests that PLG nanoparticle-based antituberculosis drug delivery system is safe and well suited for prolonged and intermittent oral chemotherapy.

Administration, Oral↗
PubMed2005

Oral solid lipid nanoparticle-based antitubercular chemotherapy.

The present study was planned to evaluate the chemotherapeutic potential of oral solid lipid nanoparticles (SLNs) incorporating rifampicin, isoniazid and pyrazinamide against experimental tuberculosis. The SLNs were prepared by the "emulsion solvent diffusion" technique with an encapsulation efficiency of 51+/-5% for rifampicin, 45+/-4% for isoniazid and 41+/-4% for pyrazinamide. Following a single oral administration to mice, therapeutic drug concentrations were maintained in the plasma for 8 days and in the organs (lungs, liver and spleen) for 10 days whereas free drugs were cleared by 1-2 days. In M. tuberculosis H37Rv infected mice, no tubercle bacilli could be detected in the lungs/spleen after 5 oral doses of drug loaded SLNs administered at every 10th day whereas 46 daily doses of oral free drugs were required to obtain an equivalent therapeutic benefit. Thus, SLN based antitubercular drug therapy forms a sound basis for reducing dosing frequency and improving patient compliance for better management of tuberculosis.

Administration, Oral↗
PubMed2005

Nano-encapsulation of azole antifungals: potential applications to improve oral drug delivery.

The present study was designed to improve the oral bioavailability of two clinically important antifungal drugs-clotrimazole and econazole. Each drug was encapsulated in nanoparticles of a synthetic polymer (polylactide-co-glycolide, PLG) or a natural polymer (alginate stabilized with chitosan). The nanoparticles were prepared by the emulsion-solvent-evaporation technique in case of PLG and by the cation-induced controlled gelification in case of alginate. Drug encapsulation efficiency was better (>90%) for the alginate formulation compared with the PLG formulation (nearly 50%). The formulations were orally administered to mice and the drugs were analyzed in plasma by a validated HPLC technique. The biodistribution/pharmacokinetic data suggested that there was a controlled drug release for 5-6 days with each of the formulations, compared with unencapsulated drugs, which were cleared within 3-4 h of oral/intravenous administration. There was a striking improvement in the relative and absolute bioavailability of each drug. Further, the drugs were detected in the tissues (lungs, liver and spleen) till 6-8 days in case of nanoparticles whereas free drugs were cleared by 12 h. Overall, the alginate formulation appeared to be better than the PLG formulation. The results emphasize the power of nanotechnology to make the concept of enhancement in oral bioavailability of azole antifungal drugs come to reality.

Administration, Oral↗
PubMed2005

Antitubercular inhaled therapy: opportunities, progress and challenges.

Pulmonary tuberculosis remains the commonest form of this disease and the development of methods for delivering antitubercular drugs directly to the lungs via the respiratory route is a rational therapeutic goal. The obvious advantages of inhaled therapy include direct drug delivery to the diseased organ, targeting to alveolar macrophages harbouring the mycobacteria, reduced risk of systemic toxicity and improved patient compliance. Research efforts have demonstrated the feasibility of various drug delivery systems employing liposomes, polymeric microparticles and nanoparticles to serve as inhalable antitubercular drug carriers. In particular, nanoparticles have emerged as a remarkably useful tool for this purpose. While some researchers have preferred dry powder inhalers, others have emphasized nebulization. Beginning with the respiratory delivery of a single antitubercular drug, it is now possible to deliver multiple drugs simultaneously with a greater therapeutic efficacy. More experience and expertise have been observed with synthetic polymers, nevertheless, the possibility of using natural polymers for inhaled therapy has yet to be explored. Several key issues such as patient education, cost of treatment, stability and large scale production of drug formulations, etc. need to be addressed before antitubercular inhaled therapy finds its way from theory to clinical reality.

Administration, Inhalation↗
PubMed2005

Solid lipid particle-based inhalable sustained drug delivery system against experimental tuberculosis.

The present study was planned to evaluate the chemotherapeutic potential of nebulized solid lipid particles (SLPs) incorporating rifampicin, isoniazid and pyrazinamide against experimental tuberculosis. The SLPs prepared by the "emulsion solvent diffusion" technique possessed a favourable mass median aerodynamic diameter suitable for bronchoalveolar drug delivery. Following a single nebulization to guinea pigs, therapeutic drug concentrations were maintained in the plasma for 5 days and in the organs (lungs, liver and spleen) for 7 days whereas free drugs were cleared by 1-2 days. The mean residence time and drug bioavailability were improved several-fold in the case of drug-loaded SLPs. A similar pharmacokinetic profile was observed in Mycobacterium tuberculosis-infected guinea pigs. On nebulization of drug-loaded SLPs to infected guinea pigs at every 7th day, no tubercle bacilli could be detected in the lungs/spleen after 7 doses of treatment whereas 46 daily doses of orally administered drugs were required to obtain an equivalent therapeutic benefit. Further, there was no evidence of any biochemical hepatotoxicity. Thus, nebulization of SLP-based antitubercular drugs forms a sound basis for improving drug bioavailability and reducing the dosing frequency for better management of pulmonary tuberculosis.

Administration, Inhalation↗
PubMed2005

Oral therapy using nanoparticle-encapsulated antituberculosis drugs in guinea pigs infected with Mycobacterium tuberculosis.

We evaluated the efficacy of nanoparticle-encapsulated antituberculosis drugs administered every 10 days versus that of daily nonencapsulated drugs against Mycobacterium tuberculosis aerosol infection in guinea pigs. Both treatments significantly reduced the bacterial count and lung histopathology, suggesting that the nanoparticle drug delivery system has potential in intermitted treatment of tuberculosis.

Administration, Inhalation↗
PubMed2004

Interference of isonicotinyl hydrazone in the microbiological analysis of rifampicin from anti-tuberculosis FDC products containing isoniazid.

Microbiological assay is a sensitive method for the estimation of rifampicin (R). In the present study, interference due to isonicotinyl hydrazone (HYD), an interaction product of R and isoniazid (H), was checked during microbiological analysis of R, employing Bacillus subtilis and Sarcina lutea. The assays were done by disc diffusion method. Both R and HYD showed linear log response curves in the range of 0.01-10microg. In the presence of HYD, R was overestimated when tested against S. lutea and underestimated in case of B. subtilis. The same extent and type of interference was observed on assay of a marketed anti-tuberculosis fixed-dose combination product, subjected to accelerated stability testing (40 degrees C/75% RH) for 1 month. This means that response of organisms used in microbiological assay of R might vary in the presence of HYD, with possibility of incorrect conclusions. Therefore, the study suggests that before a microbiological method involving a particular organism is extended to the determination of R in FDC formulations containing H, it should be tested for the influence of HYD and used only if non-interfering.

Antitubercular Agents↗
PubMed2004

Subcutaneous nanoparticle-based antitubercular chemotherapy in an experimental model.

Poly (DL-lactide-co-glycolide) (PLG) nanoparticles encapsulating three front-line antitubercular drugs, i.e. rifampicin, isoniazid and pyrazinamide, were prepared by the multiple emulsion technique and administered subcutaneously to mice for pharmacokinetic/chemotherapeutic study. A single subcutaneous dose of drug-loaded PLG nanoparticles resulted in sustained therapeutic drug levels in the plasma for 32 days and in the lungs/spleen for 36 days. The mean residence time and absolute bioavailability were increased several-fold as compared with unencapsulated drugs. Further, drug-loaded PLG nanoparticles resulted in undetectable bacterial counts in the lungs and spleen of Mycobacterium tuberculosis-infected mice, thereby demonstrating a better chemotherapeutic efficacy, as compared with daily free drug treatment. Hence, injectable PLG nanoparticles hold promise for increasing drug bioavailability and reducing dosing frequency for better management of tuberculosis.

Animals↗
PubMed2004

Chemotherapeutic potential of alginate-chitosan microspheres as anti-tubercular drug carriers.

OBJECTIVES: This study was designed to develop alginate-chitosan microspheres as drug carriers to reduce dose/dosing frequency in the management of tuberculosis (TB), which otherwise demands prolonged chemotherapy. METHODS: Alginate-chitosan microspheres encapsulating three frontline anti-tuberculous drugs (ATDs), rifampicin, isoniazid and pyrazinamide, were formulated. A therapeutic dose and a half-therapeutic dose of the microsphere-encapsulated ATDs were orally administered to guinea pigs for pharmacokinetic/chemotherapeutic evaluations, respectively. RESULTS: The drug encapsulation efficiency ranged from 65% to 85% with a loading of 220-280 mg of drug per gram microspheres. Administration of a single oral dose of the microspheres to guinea pigs resulted in sustained drug levels in the plasma for 7 days and in the organs for 9 days. The half-life and mean residence time of the drugs were increased 13- to 15-fold by microsphere encapsulation, along with an enhanced relative/absolute bioavailability. The sustained release and increase in bioavailability were also observed with a sub-therapeutic dose of the microspheres. In Mycobacterium tuberculosis H37Rv-infected guinea pigs, administration of a therapeutic dose of microspheres spaced 10 days apart produced a clearance of bacilli equivalent to conventional treatment for 6 weeks. The most important observation, however, was the documentation of therapeutic benefit with a half-therapeutic dose of the microspheres administered weekly. CONCLUSION: Alginate-chitosan microspheres hold promise as a potential natural polymer-based oral ATD carrier for better management of TB.

Alginates↗