A Retrospective Observational Study of the Microbial Etiology and Antimicrobial Susceptibility Patterns of Blood Cultures From ICU Patients at a Healthcare Facility in North India.

Introduction Bloodstream infections (BSI) are a leading source of fatalities and morbidity in hospitals. However, the clinical spectrum and antimicrobial resistance differ globally. Identifying the pathogenic spectrum and variations in antibiotic resistance is crucial for controlling BSI and preventing inappropriate antibiotic use. Material and methods This retrospective observational study was conducted at the Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, UP, India, for one year between June 2022 and June 2023. A total of 669 adult patients' blood cultures were obtained from ICUs. Blood culture was done using a BacT/Alert 3D (BioMérieux SA, Marcy-l'Étoile, France) automated system. Identification of the bacterial as well as fungal isolates was done using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), and the antimicrobial susceptibility profile was analyzed using the VITEK 2 Compact system (BioMérieux SA). Results Of the 669 blood culture samples, 213 (31.8%) showed bacterial or fungal growth. Of these 213 isolates, the most common isolate was coagulase-negative Staphylococci (21.6%), followed by Klebsiella pneumoniae (19.3%) and Acinetobacter spp. (17.8%). The majority of gram-negative bacteria were resistant to most drugs, and vancomycin and linezolid were both effective against the majority of gram-positive bacteria. Conclusion The current study found that septicemia was more frequently caused by gram-negative bacteria than by gram-positive bacteria. Blood cultures are always necessary in cases of suspected septicemia, and once the antimicrobial susceptibility profile of the pathogen causing septicemia has been determined, suitable antimicrobials should be prescribed and used to lower the antimicrobial resistance burden.

Immediate Response of Diode Laser on the Microbial Load in Subjects with Chronic Periodontitis.

Background: Chronic periodontitis is the most common dental disease reported globally as well as in India. Periodontal pathogens are usually seen in samples of gingival tissues, crevicular blood, GCF (gingival crevicular fluid), and dental plaque. Apart from the conventional mechanical treatment, laser disinfection is a recent advancement that change shows greater efficacy in reducing the disease progression and changing the bacterial flora. Aim: The present study aimed to assess the Immediate response of diode laser on the microbial load in subjects with chronic Periodontitis as assessed in saliva, crevicular blood, and GCF (gingival crevicular fluid) samples. Materials and Methods: The study recruited 90 subjects with chronic periodontitis. For split-mouth fashion, the mouth, of each participant was divided into two halves and was divided into two groups randomly. Group I (test group) subjects underwent laser disinfection (970 ± 15 nm). Group II subjects served as controls and underwent saline irrigation. For all participants, crevicular blood, saliva, and GCF samples were collected before and immediately following disinfection for microbial analysis. Results: Microbial load reduction was seen in both groups following treatment. However, a significantly higher reduction was seen in the test group with laser disinfection. Compared to the crevicular blood sample, a greater reduction was seen in saliva and GCF samples. Conclusion: The present study concludes that Diode Laser (970 ± 15 nm) application shows an immediate reduction of the bacterial load in subjects with chronic periodontitis.

Silver nanoparticles in electrochemical immunosensing and the emergence of silver-gold galvanic exchange detection.

Nanoparticle-based electrochemical immunosensors demonstrate high sensitivity toward biomarker detection due to the large surface area of the nanoparticles and their ability to amplify the signal of the target molecule. Additionally, they have a fast response time, relatively lower cost, and can be easily miniaturized for point-of-care applications. Among noble metals, silver nanoparticles (AgNPs) have been extensively used in electrochemical sensors due to their unique properties, such as catalytic activity and excellent electrical conductivity. This Feature Article describes six approaches for incorporating AgNPs in electrochemical platforms, featuring the most recent developments in the silver-gold galvanic exchange-based detection strategy. With a few exceptions, many of these detection methods use AgNP oxidation into Ag+ ions, followed by electrodeposition of Ag+ ions onto the working electrode as zero-valent Ag metal and a final stripping step using a voltammetric technique. Combining these steps provides desirable low detection limits and good sensitivity for various biomarkers. A few other methods involved the reduction of Ag+ ions and depositing them as Ag metal onto the electrode using a reagent mixture so that the striping analysis could be performed. Typically, this reagent mixture includes Ag+ ions, a reducing agent, or an enzyme substrate. Besides, AgNPs have also been directly used to modify the surface of electrodes to facilitate kinetically favored redox-mediated electrochemical reactions. In addition to Ag detection methods, this report will also provide recent examples to illustrate how the size and shape of AgNPs impact the detection limits and sensitivity of an electrochemical assay. Finally, we discuss recent developments in lab-on-a-chip type immunosensors designed explicitly for Ag-based metalloimmunoassay detection, and we envision that this article will provide a comprehensive summary of the operational principles and new insights into such immunoassay systems.

A retrospective analysis of the 5-year trends of antimicrobial resistance in gram-negative bacterial isolates from an intensive care unit at a tertiary care hospital.

Background: Intensive care units (ICUs) in developing countries constitute a high risk for patients acquiring infection by multidrug-resistant organisms (MDROs). The rise in antimicrobial resistance (AMR) threatens the effective prevention and treatment of an increasing range of infections. The present study analyzed the local trends of AMR in Gram-negative isolates of ICU patients from a tertiary care facility in North India. Methods: This retrospective study was conducted over 5 years (January 2018-December 2022). All bacterial isolates from patients admitted to ICU during the study period were included in the study, and their AMR pattern was analyzed. In addition, sensitivity trends of different antimicrobials against the common Gram-negative bacteria were analyzed, and AMR trends were analyzed over the study period. Results: Klebsiella spp. was the most common isolate in samples received from ICU. A rise of carbapenem-resistant microorganisms was observed over the study period. Escherichia coli and Klebsiella spp. showed around 10% and a 17% decrease in susceptibility to carbapenems, respectively. In contrast, a marked 29% decrease in sensitivity to carbapenems was observed in Acinetobacter spp. Conclusion: The inception of integrated stewardship measures has shown a rising trend in susceptibility and is the need of the hour to prevent the spread of MDROs. Surveillance studies help us understand the impact of AMR in hospitals and help plan prevention programs.

Evaluation of Salivary and Plasma Levels of Salivary α-Amylase in Patients of Oral Squamous Cell Carcinoma.

Aim: The aim of the study was to evaluate levels of salivary alpha-amylase (sAA) in plasma and saliva of patients with oral squamous cell carcinoma (SCC). The diurnal patterns of sAA and its response to stress were also determined. Materials and Methods: A randomized clinical study was conducted to evaluate the salivary and plasma levels of sAA in three study groups, containing ten subjects each. sAA concentration in plasma and saliva samples was measured using Bioassay Technology Laboratory human alpha-amylase kits, and the levels were compared among control and test groups. Results: In all groups, the mean plasma α-amylase level and mean saliva α-amylase level show an increasing trend with time, i.e., from morning to night, and among the groups, it was highest in Group III followed by Group II and Group I the least (Group III, Group II, and Group I) at all times with significantly higher mean values in Group III subjects at all times of a day. Conclusion: Alpha-amylase is one of the principal salivary proteins and its secretion is regulated by the sympathetic nervous system. The measurement of salivary alpha-amylase activity has been proposed to reflect stress-related changes in the autonomic nervous system, and it may be a good choice for monitoring sympathetic nervous system activity in specialized subjects. Hence, it can be concluded that salivary sAA levels can be taken as a predictable as well as reproducible marker for oral SCC or premalignant lesions.

Orofacial Features and Their Correlation in Cardiovascular Diseases.

Background: The association between cardiovascular diseases and periodontitis had different pathophysiological mechanisms involved. These mechanisms are both inflammatory and microbial. Furthermore, the possible association between two diseases can be explained by common risk factors. Aims: The present trial was carried out to establish a relation between coronary artery disease and periodontitis. Materials and Methods: One hundred and twenty-six participants advised for the angiography were included. Periodontists determined the presence of periodontitis in all participants followed by lipid profile, C-reactive protein (CRP) levels, and blood coronary angiography was then performed. The collected data were subjected to the statistical analysis, and the results were formulated. Results: The level of CRP in participants with and without coronary artery disease was 0.66 ± 1.52 and 0.53 ± 1.01, respectively, which was nonsignificant with a P = 0.63. Nonstatistically significant difference was seen in values of cholesterol and blood glucose in participants with and without coronary artery disease (P = 0.28 and P = 0.53). The mean tooth loss in participants with coronary artery disease was 14.2 ± 6.4 and in participants with no coronary artery disease was 11.8 ± 6.5, and such difference was statistically significant (P = 0.05). Conclusion: The present study establishes an association between poor oral health, periodontitis, and coronary artery disease. This study demonstrates that tooth loss which is an important feature of periodontitis is significantly associated with coronary artery disease.

Efficacy of Locking Miniplates in Managing Mandibular Fractures without Intermaxillary Fixation.

Background: In maxillofacial trauma, the most commonly encountered are mandibular fractures requiring treatment. Managing these fractures with rigid fixation abolish the intermaxillary fixation (IMF) requirement with reduction and early return to function. Aims: The present trial was carried out to assess clinically the effectiveness of new locking bone plate screw system postsurgically in mandibular fracture cases without IMF. Materials and Methods: In 18 subjects, the fracture site was exposed, fracture segments were reduced and approximated keeping the occlusal relationship is desirable using locking 2 mm mini plates and screws without IMF. The subjects were followed every week for initial 4 weeks followed by evaluation for up to 6 months every month to assess clinical and radiographic healing and the results were formulated. Results: Road traffic accident was the cause in 10 subjects (55.5%), followed by assault in 22.2% (n = 4) subjects, and fall from height in 16.6% (n = 3) subjects. Parasymphysis was involved in 44.4% (n = 8), followed by symphysis in 11.1% (n = 2) subjects. A minor complication of wound dehiscence was seen in 5.5% (n = 1) subjects that were managed conservatively and a major complication of infection was also seen in 1 subject that required removal of the plate at 4 weeks of follow-up. Following plate removal, IMF was done for that subject. All other sites were healed uneventfully. Primary healing in bone was seen in 94.4% (n = 17) subjects and it was not seen in the case with infection. Conclusion: Within the limitations, the present study concluded that the locking miniplate system is highly effective and reliable in treating mandibular fractures with acceptable results and a very low postoperative complications rate.

Paper Biosensor for the Detection of NT-proBNP Using Silver Nanodisks as Electrochemical Labels.

We report on the use of silver nanodisks (AgNDs), having a diameter of 50 ± 8 nm and a thickness of 8 ± 2 nm, as electrochemical labels for the detection of a model metalloimmunoassay for the heart failure biomarker NT-proBNP. The detection method is based on an electrochemically activated galvanic exchange (GE) followed by the detection of Ag using anodic stripping voltammetry (ASV). The AgNDs labels are superior to Ag nanocubes and Ag nanospheres in terms of the dynamic range for both the model and NT-proBNP metalloimmunoassays. The linear dynamic range for the model composite is 1.5 to 30.0 pM AgNDs. When AgND labels are used for the NT-proBNP assay, the dynamic range is 0.03-4.0 nM NT-proBNP. The latter range fully overlaps the risk stratification range for heart failure from 53 pM to 590 pM. The performance improvement of the AgNDs is a result of the specific GE mechanism for nanodisks. Specifically, GE is complete across the face of the AgNDs, leaving behind an incompletely exchanged ring structure composed of both Ag and Au.

Plastic-based lateral flow immunoassay device for electrochemical detection of NT-proBNP.

Here we report an easily fabricated, plastic-based lateral flow device for carrying out metalloimmunoassays. The device is called ocFlow to emphasize the open-channel design. We have shown that the ocFlow is capable of magnetic microbead (MµB)-based metalloimmunoassays for the detection of two types of immunoconjugates: a model composite (MC) and a sandwich immunoassay for the heart failure marker NT-proBNP. In both assays, Ag nanoparticles (AgNPs) were used as electrochemically detectable labels. NT-proBNP and MC concentrations as low as 750.0 pM and 10.0 pM, respectively, could be detected using the ocFlow device. Four key conclusions can be drawn from the results presented herein. First, immunoconjugates attached to the MµBs can be transported in the flow channel using combined hydrodynamic and capillary pressure passive pumping. Second, the ocFlow device is capable of on-chip storage, resolvation, and conjugate formation of both the MC and NT-proBNP composites. Third, electrochemical detection can be conducted on analytes suspended in serum by rinsing the electrodes with a wash buffer. Finally, and perhaps most significantly, the assay is quantitative and has a detection limit for NT-proBNP in the high picomolar range when the necessary reagents are stored on the device in a dry form.

Detection Efficiency of Ag Nanoparticle Labels for a Heart Failure Marker Using Linear and Square-Wave Anodic Stripping Voltammetry.

In this article, we compare linear sweep anodic stripping voltammetry (LASV) and square-wave anodic stripping voltammetry (SWASV) for detection of a nano metalloimmunoassay. Two separate immunoassays were examined: a model assay, based on interactions between antibodies, and a sandwich assay for the heart failure marker NT-proBNP. In both cases, one antibody is linked to a magnetic microbead, and one is linked to a spherical Ag nanoparticle label. Electrochemical detection is carried out on a paper device. The three analytical figures of merit studied were the precision of the measurements, the calibration sensitivity, and the limit of detection (LOD). For the NT-proBNP assay, the results show that after optimization of the pulse amplitude and frequency of the potential input for SWASV, the detection efficiency is substantially higher compared to LASV. Specifically, the calibration sensitivity increased by up to ~40 fold, the average coefficient of variation decreased by ~40%, and the (LOD) decreased to 300.0 pM. Finally, for a model immunoassay, a ~10-fold decrease in the LOD was observed for SWASV compared to LASV.

Giant cystic pulmonary hamartoma-images.

Hamartoma is the commonest benign tumor of the lung. They usually present as an asymptomatic solitary solid nodule of varying size, located peripherally in the lung parenchyma and picked up incidentally in a chest X-ray. Rarely, they may be intra-bronchial in location. A giant cystic variant of hamartoma is very rare, with only a few cases reported in literature so far. It may be misdiagnosed as any other cystic disease of the lung and thus get mismanaged. We herewith present the images of a patient with a giant cystic pulmonary hamartoma who presented with respiratory distress.

A Cross-Sectional Study on the Evidence-Based Dentistry, Perception Basis, and Use of Articaine Among Dental Practitioners.

Background: Many dentists use articaine as their choice of local anesthetic agent. However, the use of articaine is limited to inferior alveolar nerve blocks (IANBs), and literature data are scarce concerning its perception and choice among various dental practitioners. Aim: The aim of the present study was to assess the extent of articaine use as a local anesthetic in dentistry, its perception basis, and the consistency of evidence of the efficacy and safety of articaine in recent practice. Methods: The present study utilized a survey tool that was given to all the participating dental practitioners, and the participants were given five minutes to fill out the survey questionnaire. The questionnaire was in English and had 14 questions to be answered. The data gathered were statistically assessed to formulate the results. Results: The results of this cross-sectional survey reported that articaine is used as a choice of local anesthetic by more than half of the participating dental practitioners. Sixty percent (n = 480) participants used articaine in their practice, followed by lidocaine, which was used by 33% (n = 264) dental practitioners, mepivacaine by 2% (n = 16) participants, prilocaine by 1% (n = 8) dental practitioners, and other local anesthetics by 4% (n = 32) participants, respectively. Concerning the safety and efficacy of articaine use, 43% used it for all procedures except for IANBs, whereas 20% used it for all procedures, including IANBs. Conclusion: Despite the reported efficacy and safety of articaine as a local anesthetic for all dental procedures, many dental practitioners refrain from using it, especially for IANBs. These data depict a difference between current research evidence and reported clinical practice.

Dual-Shaped Silver Nanoparticle Labels for Electrochemical Detection of Bioassays.

In this paper we demonstrate the use of dual-shaped silver nanoparticles (AgNPs) as detection labels for electrochemical bioassays. The key finding is that by using AgNP labels having two different shapes simultaneously, the limit of detection (LOD) for the assays is lowered compared to using either of the two shapes separately. The two shapes were silver nanocubes (AgNCs) having edge lengths of 40 ± 4 nm and spherical AgNPs (sAgNPs) having diameters of 20 ± 3 nm. Two different bioassays were examined. In both cases the Ag labels were functionalized with antibodies. In the one assay, the labels are directly linked to a second antibody immobilized on magnetic beads. In the second assay, the antibodies on the AgNP labels and the antibodies on the magnetic beads are linked via a peptide. The peptide is N-terminal prohormone brain natriuretic peptide (NT-proBNP), which is a heart failure marker. The efficacy of the two electrochemical assays as a function of the ratio of the two labels was investigated using a galvanic exchange/anodic stripping voltammetry method. The key finding is that by optimizing the ratio of the two types of AgNP labels, it is possible to decrease the LOD of the assays without compromising the dynamic range compared to using either of the two labels independently. This made it possible to achieve the clinically relevant range for NT-proBNP analysis used by physicians for heart failure risk stratification.

A Study to Assess the Bond Strength of Acrylic Teeth With Different Retentive Features.

BACKGROUND AND AIM: Flexible denture base has been gaining attention as a denture base material because of its toxicological safety, comfort, and enhanced aesthetics. Debonding of acrylic teeth from the flexible denture base material has posed a great problem to the clinician and patient. This study aimed at comparing the bond strength between flexible denture base with acrylic teeth having different mechanical modifications. MATERIALS AND METHODS: Forty mandibular molar teeth (Combination Acry Rock, Badia Polesine (Ro), Italy) were used in four groups for mechanical modifications on the ridge lap area. The groups were group 1 (no mechanical modifications), group 2 (round groove 2 mm in diameter and 2 mm deep on the ridge lap surface), group 3 (horizontal slot 2 mm deep, 2 mm wide, and 4 mm long prepared on the ridge lap surface of the teeth), and group 4 (T-shaped groove 2 mm deep, 2 mm wide, and length of 4 mm mesiodistally and 2 mm buccolingually prepared with a straight fissure bur). The acrylic teeth were attached to a wax block of dimension 1.2 cm × 1.2 cm × 2.5 cm. These were flasked and dewaxed, followed by injection molding with Valplast flexible denture base material. The bond strength was assessed by attaching the specimens to universal testing machine tested under a tensile load at a cross-head speed of 1 mm/min till it fractured. Data obtained were statistically evaluated by one-way analysis of variance and post hoc test. RESULTS: There was significant increase in mean bond strength after various mechanical modifications. Group with T-shaped diatoric hole showed greatest bond strength value compared to other groups. CONCLUSION: Incorporating mechanical retentive features with increased surface area and undercut can improve the bonding of acrylic teeth to flexible denture base.

Postmarket surveillance: a review on key aspects and measures on the effective functioning in the context of the United Kingdom and Canada.

Regulatory approvals for the marketing of medicinal products authorize medical practitioners to prescribe drugs to a group of patients that are defined within the license of the medicinal product. However, such prescriptions are carried out in a controlled manner. Prior to being approved, the medicinal product will have been evaluated in a population pool containing fewer than 5,000 patients and in a predesigned environment where several factors may be lacking, such as the absence of women of childbearing potential, geriatric patients and paediatric patients. Therefore, it is not surprising that several major adverse drug reactions are detected only when the product has been prescribed to the general population. National and international regulatory bodies have devised systems for monitoring medicinal products after marketing, commonly known as postmarketing surveillance systems. Postmarketing surveillance refers to the process of monitoring the safety of drugs once they reach the market, after the successful completion of clinical trials. The primary purpose for conducting postmarketing surveillance is to identify previously unrecognized adverse effects as well as positive effects. The Yellow Card scheme, practiced in the United Kingdom and the Canada Vigilance Program adopted in the Canadian jurisdiction, are two of the most successful postmarketing surveillance systems implemented across the world. Therefore, this article intends to discuss postmarketing surveillance and its role in the context of the United Kingdom and Canadian jurisdictions with a view on presenting key aspects and measures that are employed for operating an efficient postmarketing surveillance system in regulated markets.

Optimal parameter values for the control of gene regulation.

How does a transcription network arrive at the particular values of biochemical interactions defining it? These interactions define DNA-transcription factor interaction, degradation rates of proteins, promoter strengths, and communication of the environmental signal with the network. What is the structure of the fitness landscape that is defined by the space that these parameters can take on? To answer these questions, we simulate the simplest regulatory network: a transcription factor, R, and a target protein, T. We use a cost-benefit analysis to evolve the network and eventually arrive at values of parameters which maximize fitness. We show that for a given topology, multiple parameter sets exist which confer maximal fitness to the cell, and that pairwise correlations exist between parameters in optimal sets. In addition, our results indicate that in the parameter space defining the interactions in a topology, a highly rugged fitness landscape exists.

Revisiting demand rules for gene regulation.

Starting with Savageau's pioneering work regarding demand rules for gene regulation from the 1970s, here, we choose the simplest transcription network and ask: how does the cell choose a particular regulatory topology from all available possibilities? According to the demand rules, a cell chooses an activator based regulation of a target if the target protein is required for most of the time. On the other hand, if the target protein is only required sporadically, its control tends to be via a repressor-based regulatory topology. We study the natural distribution of topologies at genome, systems, and micro-levels in E. coli and observe deviations from demand rules. Analyzing the regulation of amino acid biosynthesis, transport, and carbon utilization in E. coli and B. subtilis, and comparing choice of topology with demand, we observe an alternate pattern emerging. Simulations of networks are used to help explain the natural distribution of topologies in nature. Overall, our results indicate that the choice of topology is drawn randomly from a pool of all networks which satisfy the dynamic requirements of the cell, as dictated by physiology. In short, our results suggest that the cell picks "whatever works".

Shipbreaking in the developing world: problems and prospects.

The global shipping industry relies upon the developing world to dispose of retired deep-sea vessels through the process of shipbreaking. In doing so the industry avoids the burdens of complying with developed world standards for the management of hazardous waste. Occupational and environmental health (OEH) risks associated with dismantling of beached ships, primarily in India and Bangladesh, are significant. Worldwide concerns about these risks, which arose in the late 1990s, and activism by domestic organizations appear to be gathering momentum for global and domestic OEH reforms. This article addresses recent developments in characterizing these risks and in proposals to control them.