Adverse effects of a single dose of gentamicin in adults: a systematic review

Developing AAV-delivered nonsense suppressor tRNAs for neurological disorders

Adeno-associated virus (AAV)-based gene therapy is a clinical stage therapeutic modality for neurological disorders. A common genetic defect in myriad monogenic neurological disorders is nonsense mutations that account for about 11% of all human pathogenic mutations. Stop codon readthrough by suppressor transfer RNA (sup-tRNA) has long been sought as a potential gene therapy approach to target nonsense mutations, but hindered by inefficient in vivo delivery. The rapid advances in AAV delivery technology have not only powered gene therapy development but also enabled in vivo preclinical assessment of a range of nucleic acid therapeutics, such as sup-tRNA. Compared with conventional AAV gene therapy that delivers a transgene to produce therapeutic proteins, AAV-delivered sup-tRNA has several advantages, such as small gene sizes and operating within the endogenous gene expression regulation, which are important considerations for treating some neurological disorders. This review will first examine sup-tRNA designs and delivery by AAV vectors. We will then analyze how AAV-delivered sup-tRNA can potentially address some neurological disorders that are challenging to conventional gene therapy, followed by discussing available mouse models of neurological diseases for in vivo preclinical testing. Potential challenges for AAV-delivered sup-tRNA to achieve therapeutic efficacy and safety will also be discussed.

The interactive effects of medicinal dyes with conventional antimicrobials against skin pathogens

AIMS

This study aimed to explore potential synergistic effects of medicinal dyes with antimicrobials against pathogens responsible for skin infections.

METHODS AND RESULTS

Antimicrobial testing was conducted using minimum inhibitory concentrations and minimum bactericidal/fungicidal concentration assays. The fractional inhibitory index (ΣFIC) of combinations was calculated, and isobolograms were constructed on selected combinations. Toxicity studies were conducted using the brine-shrimp lethality assay. Combination (1:1 ratio) studies noted that 26% of dye-antibiotic combinations were synergistic against the Gram-positive strains, 15% against the Gram-negative strains, and 14% against the yeasts. The Mercurochrome: Betadine® combination noted synergy at ratios against all the Staphylococcus aureus strains with ΣFIC values ranging from 0.05 to 0.48. The combination of Gentian violet with Gentamycin noted a 15-fold decrease in toxicity, and a selectivity index of 977.50 against the Escherichia coli (DSM 22314) strain. Time-kill studies were conducted on the combinations with the highest safe selectivity index (SI) value and lowest safe SI value i.e. Gentian violet with Gentamycin and Malachite green with Neomycin. Both combinations demonstrated better antimicrobial activity in comparison to the independent values and the controls.

CONCLUSION

This study highlights the potential for medicinal dye combinations as a treatment for skin infections.

Antibacterial effectiveness of trans-cinnamaldehyde against foodborne Enterobacteriaceae and its adjuvant effect with gentamicin

The Enterobacteriaceae family is recognized as a primary group of Gram-negative pathogens responsible for foodborne illnesses and is frequently associated with antibiotic resistance. The present study explores the natural-based compound trans-cinnamaldehyde (TC) against drug-resistant Enterobacteriaceae and its synergism with gentamicin (GEN) to address this issue. The research employs three strains of Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae, previously isolated from shrimp. The antibacterial activity was evaluated by the disk diffusion method, microdilution test, kinetics of growth, and time-kill curve. In addition, the synergistic effect between TC/GEN was investigated by checkerboard assay. All strains showed sensitivity to TC with an inhibition zone diameter > 35 mm. The TC showed inhibitory and bactericidal action in the most tested bacteria around 625 μg/mL. Sub-inhibitory amounts (1/2 and 1/4 MIC) of TC interfered with the growth kinetics by lag phase extension and decreased the log phase. Time-kill curves show a reduction of viable cells after the first hour of TC treatment at bactericidal concentrations. The synergistic effect between TC/GEN was observed for E. coli and E. cloacae strains with FICi ranging from 0.15 to 0.50. These findings, therefore, suggest TC as a promising alternative in the fight against drug-resistant Enterobacteriaceae that can cause foodborne illnesses.

Fortified Dual-Spectral Overlap with Enhanced Colorimetric/Fluorescence Dual-Response Immunochromatography for On-Site Bimodal-Type Gentamicin Monitoring

Immunochromatography (ICA) remains untapped toward enhanced sensitivity and applicability for fulfilling the nuts and bolts of on-site food safety surveillance. Herein, we report a fortified dual-spectral overlap with enhanced colorimetric/fluorescence dual-response ICA for on-site bimodal-type gentamicin (Gen) monitoring by employing polydopamine (PDA)-coated AuNPs (APDA) simultaneously serving as a colorimetric reporter and a fluorescence quencher. Availing of the enhanced colorimetric response that originated from the PDA layer, the resultant APDA exhibits less required antibody and immunoprobes in a single immunoassay, which facilitates improved antibody utilization efficiency and immuno-recognition in APDA-ICA. Further integrated with the advantageous features of fortified excitation and emission dual-spectral overlap for the Arg/ATT-AuNCs, this APDA-ICA with a "turn on/off" pattern achieves the visual limits of detection of 1.0 and 0.5 ng mL-1 for colorimetric and fluorescence patterns (25- and 50-fold lower than standard AuNPs-ICA). Moreover, the excellent self-calibration and satisfactory recovery of 79.03-118.04% were shown in the on-site visual colorimetric-fluorescence analysis for Gen in real environmental media (including real river water, an urban aquaculture water body, an aquatic product, and an animal byproduct). This work provides the feasibility of exploiting fortified dual-spectral overlap with an enhanced colorimetric/fluorescence dual response for safeguarding food safety and public health.

Gentamycin irrigation significantly reduces 28-day surgical site infection after emergency neurosurgery

OBJECTIVE

This study aims to evaluate the effectiveness of gentamycin irrigation in preventing postoperative surgical site infection (SSI) in emergency neurosurgical procedures.

METHODS

A total of 518 consecutive emergency neurosurgeries, including craniotomies, endoscopic and burr hole procedures were reviewed retrospectively. Patients received either only normal saline (NS) irrigation or NS irrigation with gentamycin added (80 mg/L) during the whole process of surgery. SSIs including wound infection and intracranial infection were the primary outcome. SSI was considered while purulence was observed during wound dressing and confirmed with bacterial culture of wound exudation. In addition, positive result of bacterial growth culture of cerebrospinal fluid was also considered as infection. Infection rates were calculated 28 days after surgery. Statistical analysis was performed using t test or Chi-squared test where appropriate.

RESULTS

This study included 444 patients. Gentamycin was used in 179 (40.3%) patients. Only 2 (1.1%) of 179 patients receiving gentamycin irrigation had an infection. However, among the other 265 patients receiving only NS irrigation, the infection rate was 8.3%. With the addition of gentamycin, the infection rate was decreased by 86.7% (P = 0.001). The two infected patients in gentamycin group were compromised postoperatively: one patient had removed his own extraventricular drainage tube accidentally due to restlessness, and the other had severely contaminated his wound with vomitus during the intracranial drainage tube removal process. If these two patients were excluded from analysis, the effective infection rate using gentamycin irrigation is 0%.

CONCLUSION

The gentamycin plus NS irrigation during emergency neurosurgical procedures can lead to a significantly lower rate of postoperative infection than when NS is used alone.

Acute Kidney Injury in a Previously Healthy 56-Year-Old Male Following a Direct Visual Internal Urethrotomy of a Bulbar Stricture

Acute kidney injury (AKI) is a frequent finding in acutely ill and hospitalized patients arising from various etiologies. Anuric AKI, a more pronounced form of AKI in which less than 100 cc of urine is produced per day, is most frequently encountered in hospitalized, septic, and post-surgical patients, often secondary to shock or bilateral urinary tract obstruction. The development of anuric AKI in previously healthy patients after outpatient urological procedures presents a unique challenge to physicians, as many outpatient procedures require the routine perioperative administration of multiple nephrotoxic medications. Further complicating this clinical scenario, some surgical procedures that intrinsically involve iatrogenic injury to the kidney, ureter, bladder, or nearby organ can rarely lead to a phenomenon known as reflex anuria, an anuric state typically associated with AKI. Here, we report an unusual case of a previously healthy 56-year-old male who developed anuric AKI two days after direct visual internal urethrotomy (DVIU) for the treatment of a bulbar stricture. Non-contrast CT revealed no signs of an obstructive process, and laboratory findings supported an intrarenal cause of AKI. Consideration was given to non-steroidal anti-inflammatory drugs (NSAID)-induced nephrotoxicity, gentamicin-associated acute tubular necrosis, and propofol infusion syndrome, in addition to their potential synergistic effects. We also explore this as the first reported case of reflex anuria occurring at the level of the bulbar urethra, as most cases have involved direct injury to the kidney or ureter. Over the course of 10 days, our patient responded well to treatment with supportive measures and dialysis, with his vomiting, electrolyte abnormalities, renal state, and anuria eventually improving.

Direct and Continuous Monitoring of Multicomponent Antibiotic Gentamicin in Blood at Single-Molecule Resolution

Point-of-care monitoring of small molecules in biofluids is crucial for clinical diagnosis and treatment. However, the inherent low degree of recognition of small molecules and the complex composition of biofluids present significant obstacles for current detection technologies. Although nanopore sensing excels in the analysis of small molecules, the direct detection of small molecules in complex biofluids remains a challenge. In this study, we present a method for sensing the small molecule drug gentamicin in whole blood based on the mechanosensitive channel of small conductance in Pseudomonas aeruginosa (PaMscS) nanopore. PaMscS can directly detect gentamicin and distinguish its main components with only a monomethyl difference. The 'molecular sieve' structure of PaMscS enables the direct measurement of gentamicin in human whole blood within 10 min. Furthermore, a continuous monitoring device constructed based on PaMscS achieved continuous monitoring of gentamicin in live rats for approximately 2.5 h without blood consumption, while the drug components can be analyzed in situ. This approach enables rapid and convenient drug monitoring with single-molecule level resolution, which can significantly lower the threshold for drug concentration monitoring and promote more efficient drug use. Moreover, this work also lays the foundation for the future development of continuous monitoring technology with single-molecule level resolution in the living body.

Investigation of the effects of crocin on inflammation, oxidative stress, apoptosis, NF-κB, TLR-4 and Nrf-2/HO-1 pathways in gentamicin-induced nephrotoxicity in rats

The primary limitation of gentamicin (Gm) treatment is its potential to induce nephrotoxicity, which can restrict both its duration and efficacy. This study aims to investigate the protective effects of Crocin (Cr) against Gm-induced nephrotoxicity and its underlying mechanisms, including inflammation, apoptosis, TLR-4, Nrf-2/HO-1 pathways. 36 Sprague Dawley rats were divided into 6 groups for the study. Group I received only saline. Groups II and III were administered 25 and 50 mg/kg of crocin, respectively. Group IV was treated with 80 mg/kg of Gm. Groups V and VI received 25 and 50 mg/kg of crocin, respectively, in addition to Gm administration. Crocin demonstrated protective effects on kidney tissue. It down-regulated the genes NF-κB, COX-2, TLR-4, Bax, and Caspase-3, while up-regulating Bcl-2, Nrf-2, and HO-1. In conclusion, these findings hold promise for the prevention of Gm-induced nephrotoxicity through the modulation of the Nrf-2/HO-1 pathway.

Management of cervicofacial infection: a 7-year retrospective study

OBJECTIVE

We aimed to describe and analyze the epidemiologic and clinical variables associated with, treatment for, and development of cervicofacial infection (CFI).

STUDY DESIGN

We retrospectively examined 201 patients older than 14 years who had met the CFI diagnostic criteria and whose treatment required hospitalization and intervention under general anesthesia at our hospital. We performed chi-square tests to compare proportions in categorical variables and either the Student t test or the Wilcoxon signed-rank test to compare quantitative variables. We performed an analysis of variance to compare 3 or more categories and either Pearson or Spearman correlation coefficient analysis to examine the correlations between quantitative variables.

RESULTS

The majority (85.07%) of the CFIs were of odontogenic origin. The mean hospitalization length was 4.58 days. Patients with diabetes who used tobacco and/or alcohol had a significantly longer length of hospitalization and several postoperative complications.The most common symptoms were pain, trismus and toothache. Symptoms of fever and nausea were associated with longer hospitalization. The most affected anatomic spaces were submandibular and pterygomandibular. Buccal and infraorbital, temporal, and parotid spaces were associated with longer hospitalization.

CONCLUSIONS

Most CFIs are of odontogenic origin. Diabetes and tobacco and alcohol use are important risk factors. Treatment should be surgical and target the cause of infection. Timely referrals are important when patients present symptoms compatible with CFI for immediate treatment.

Debilitating Gentamicin Ototoxicity: Case Report and Recommendations Against Routine Use in Surgical Prophylaxis

INTRODUCTION

Aminoglycoside antibiotics such as gentamicin are bactericidal and effective against gram negative organisms and act synergistically against gram positive organisms, including Staphylococcus aureus. However, they have serious adverse effects such as nephrotoxicity and ototoxicity. Gentamicin ototoxicity may occur after a single dose and results in decreased vestibular function, which is frequently debilitating and often permanent.

OBJECTIVE

To emphasize the risk of gentamicin ototoxicity and suggest alternative antibiotics in penicillin-allergic patients undergoing surgery.

CASE SUMMARY

We present a case of a woman with preexisting Meniere's Disease who received gentamicin 400 mg perioperatively for a sigmoidectomy due to a penicillin allergy listed in the patient's medical record. The patient developed severe ototoxicity preventing her from working or driving. Physical examination was remarkable for a broad-based gait requiring assistance to walk and bilateral corrective saccades. Vestibular testing revealed high-grade bilateral vestibular loss associated with all semicircular canals, a considerable decline compared to her function 3 years prior.

DISCUSSION

Gentamicin is indicated for surgical prophylaxis when a patient has a true allergy to penicillins and cannot receive cephalosporins, though alternatives exist. True allergies include IgE-mediated illness (anaphylaxis, bronchospasm, or urticaria 30-60 minutes after administration) or exfoliative reactions (Stevens-Johnson Syndrome or Toxic Epidermal Necrolysis). The authors encourage more prudent use of gentamicin, especially in patients susceptible for debilitating otologic insults, and offer recommendations for alternative agents prior to using gentamicin.

Intra-soft tissue and intramedullary antibiotic perfusion in combination with negative pressure wound therapy

OBJECTIVE

Intra-soft tissue and intramedullary antibiotic perfusion (iSAP and iMAP), which combine continuous administration of antibiotic solution to the wound and negative pressure wound therapy (NPWT), have been reported to be a useful management approach for hard-to-heal ulcers in the field of orthopaedic surgery. We report the efficacy of this treatment and discuss the key points.

METHOD

The recipients of this treatment had contaminated fresh severe trauma with a high risk of infection, or hard-to-heal ulcers which were expected to be difficult to manage with conventional NPWT alone. Continuous administration of 1200µg/ml of gentamicin (GM) solution to the wound was performed along with NPWT. The GM solution was administered subcutaneously using a small catheter for iSAP, while intramedullary administration used a bone marrow needle for iMAP.

RESULTS

iSAP was employed in all 10 patients who took part, and iMAP in three of these patients. The average treatment time was 13.6 days with iSAP and 9.3 days with iMAP. The mean serum GM level during the therapy was 1.02µg/ml. Moderate GM-induced acute kidney injury was suspected in one case, but resolved spontaneously after GM administration was stopped. Favourable wound bed preparation was achieved in all cases without recurrence of infection.

CONCLUSION

Combination with continuous suction by NPWT is able to keep the local concentration of antibiotic above the minimum inhibitory concentration of biofilm-coated bacteria within the wound. We have referred to this treatment as continuous local antibiotic perfusion. Further investigation of local pharmacodynamics in the wound and side-effects of this treatment are warranted.

Therapeutic approaches for Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a monogenic muscle-wasting disorder and a priority candidate for molecular and cellular therapeutics. Although rare, it is the most common inherited myopathy affecting children and so has been the focus of intense research activity. It is caused by mutations that disrupt production of the dystrophin protein, and a plethora of drug development approaches are under way that aim to restore dystrophin function, including exon skipping, stop codon readthrough, gene replacement, cell therapy and gene editing. These efforts have led to the clinical approval of four exon skipping antisense oligonucleotides, one stop codon readthrough drug and one gene therapy product, with other approvals likely soon. Here, we discuss the latest therapeutic strategies that are under development and being deployed to treat DMD. Lessons from these drug development programmes are likely to have a major impact on the DMD field, but also on molecular and cellular medicine more generally. Thus, DMD is a pioneer disease at the forefront of future drug discovery efforts, with these experimental treatments paving the way for therapies using similar mechanisms of action being developed for other genetic diseases.

Metformin beyond an anti-diabetic agent: A comprehensive and mechanistic review on its effects against natural and chemical toxins

In addition to the anti-diabetic effect of metformin, a growing number of studies have shown that metformin has some exciting properties, such as anti-oxidative capabilities, anticancer, genomic stability, anti-inflammation, and anti-fibrosis, which have potent, that can treat other disorders other than diabetes mellitus. We aimed to describe and review the protective and antidotal efficacy of metformin against biologicals, chemicals, natural, medications, pesticides, and radiation-induced toxicities. A comprehensive search has been performed from Scopus, Web of Science, PubMed, and Google Scholar databases from inception to March 8, 2023. All in vitro, in vivo, and clinical studies were considered. Many studies suggest that metformin affects diseases other than diabetes. It is a radioprotective and chemoprotective drug that also affects viral and bacterial diseases. It can be used against inflammation-related and apoptosis-related abnormalities and against toxins to lower their effects. Besides lowering blood sugar, metformin can attenuate the effects of toxins on body weight, inflammation, apoptosis, necrosis, caspase-3 activation, cell viability and survival rate, reactive oxygen species (ROS), NF-κB, TNF-α, many interleukins, lipid profile, and many enzymes activity such as catalase and superoxide dismutase. It also can reduce the histopathological damages induced by many toxins on the kidneys, liver, and colon. However, clinical trials and human studies are needed before using metformin as a therapeutic agent against other diseases.

Review on PLGA Polymer Based Nanoparticles with Antimicrobial Properties and Their Application in Various Medical Conditions or Infections

The rise in the resistance to antibiotics is due to their inappropriate use and the use of a broad spectrum of antibiotics. This has also contributed to the development of multidrug-resistant microorganisms, and due to the unavailability of suitable new drugs for treatments, it is difficult to control. Hence, there is a need for the development of new novel, target-specific antimicrobials. Nanotechnology, involving the synthesis of nanoparticles, may be one of the best options, as it can be manipulated by using physicochemical properties to develop intelligent NPs with desired properties. NPs, because of their unique properties, can deliver drugs to specific targets and release them in a sustained fashion. The chance of developing resistance is very low. Polymeric nanoparticles are solid colloids synthesized using either natural or synthetic polymers. These polymers are used as carriers of drugs to deliver them to the targets. NPs, synthesized using poly-lactic acid (PLA) or the copolymer of lactic and glycolic acid (PLGA), are used in the delivery of controlled drug release, as they are biodegradable, biocompatible and have been approved by the USFDA. In this article, we will be reviewing the synthesis of PLGA-based nanoparticles encapsulated or loaded with antibiotics, natural products, or metal ions and their antibacterial potential in various medical applications.

Antibiotic-Loaded Boron Nitride Nanoconjugate with Strong Performance against Planktonic Bacteria and Biofilms

Protecting surfaces from biofilm formation presents a significant challenge in the biomedical field. The utilization of antimicrobial component-conjugated nanoparticles is becoming an attractive strategy against infectious biofilms. Boron nitride (BN) nanomaterials have a unique biomedical application value due to their excellent biocompatibility. Here, we developed antibiotic-loaded BN nanoconjugates to combat bacterial biofilms. Antibiofilm testing included two types of pathogens, Staphylococcus aureus and Escherichia coli. Gentamicin was loaded on polydopamine-modified BN nanoparticles (GPBN) to construct a nanoconjugate, which was very effective in killing E. coli and S. aureus planktonic cells. GPBN exhibited equally strong capacity for biofilm destruction, tested on preformed biofilms. A 24 h treatment with the nanoconjugate reduced cell viability by more than 90%. Our results suggest that GPBN adheres to the surface of the biofilm, penetrates inside the biofilm matrix, and finally deactivates the cells. Interestingly, the GPBN coatings also strongly inhibited the formation of bacterial biofilms. Based on these results, we suggest that GPBN could serve as an effective means for treating biofilm-associated infections and as coatings for biofilm prevention.

Diacerein modulates TLR4/ NF-κB/IL-1β and TRPC1/CHOP signalling pathways in gentamicin-induced parotid toxicity in rats

The present study aimed to identify the possible protective effect of diacerein (DIA) on gentamicin (GNT)-induced parotid toxicity in rats. DIA was administered in the presence and absence of GNT. Thirty-two Wistar adult male rats were randomly arranged into four groups: control, DIA (50 mg/kg/day), GNT (100 mg/kg) and GNT+DIA groups for 8 days. Parotid oxidative stress parameters, besides inflammatory and apoptotic biomarkers, were evaluated. Salivary flow rate, transient receptor potential canonical 1 (TRCP1), and C/EBP homologous protein (CHOP) in parotid tissue were measured. A parotid histopathological examination and an interleukin-1 beta (IL-1β) immunohistochemical study were also performed. GNT significantly increased parotid oxidative stress, inflammatory, apoptotic and CHOP biomarkers with decreased salivary flow rate and TRCP1 level. A histopathological picture of parotid damage and high IL-1β immunoexpression were detected. DIA significantly normalized the distributed oxidative, inflammatory and apoptotic indicators, CHOP and TRCP1, with a prompt improvement in the histopathological picture and a decrease in IL-1β immunoexpression. These results reported that DIA protects against GNT-induced parotid toxicity via modulation of TLR4/NF-κB/IL-1β and TRPC1/CHOP signalling pathways.

Curcumin and Vitamin C Attenuate Gentamicin-Induced Nephrotoxicity by Modulating Distinctive Reactive Species

Gentamicin remains widely used in all age groups despite its well-documented nephrotoxicity; however, no adjuvant therapies have been established to counteract this side effect. Our study aimed to experimentally determine whether curcumin and vitamin C have nephroprotective effects and whether certain reactive species could be used as markers of early gentamicin nephrotoxicity. Wistar adult male rats were evenly distributed into four groups: control, gentamicin, curcumin and gentamicin, vitamin C and gentamicin (gentamicin: 60 mg/kg/day, intraperitoneally, 7 days). We determined renal function (urea, creatinine), oxidative stress (malondialdehyde, nitric oxide, 3-nitrotyrosine, total oxidative stress), and antioxidant and anti-inflammatory status (thiols, total antioxidant capacity, interleukin-10). Nephrotoxicity was successfully induced, as shown by the elevated creatinine levels in the gentamicin group. In contrast, supplementation with curcumin and vitamin C prevented an increase in urea levels while decreasing total oxidative stress levels compared to the gentamicin group. Moreover, vitamin C and curcumin distinctively modulate the levels of nitric oxide and malondialdehyde. Histological analysis showed more discrete lesions in rats that received vitamin C compared to the curcumin group.

Intravesical gentamicin treatment for recurrent urinary tract infections: A systematic review over the last two decades

Objectives:

Recurrent urinary tract infections (rUTIs) have a significant effect on a patient’s quality of life and frequent use of antibiotics increases multi-drug resistance. Previous research on intravesical antibiotics suggests that this has a local effect on bacteria with reduced systemic absorption and associated side effects. We conducted a systematic review to assess the effectiveness and adverse effects of intravesical gentamicin treatment.

Methods:

Systematic review of all English published articles from January 2001 to October 2021 according to the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards.

Results:

A total of 139 studies were identified, 20 full-text articles were screened and 6 subsequently included totalling 166 patients. All studies reported a decrease in the mean number of urinary tract infections (UTIs) with a significant reduction ( p = 0.0025 and p < 0.004) in two studies. When the number of breakthrough UTIs on prophylactic gentamicin installations was assessed, 65% ( n = 86/133) remained UTI free. Throughout treatment, 99% of serum gentamicin levels were <0.3 ng/dL, and reported instances of increased creatinine were low (2%). A decrease in the growth of multi-drug-resistant bacteria was reported in two papers ( p = 0.065 and p = 0.04).

Conclusion:

Intravesical gentamicin seems to be an effective treatment in patients with symptomatic rUTIs. The evidence suggests it also reduces UTIs caused by multi-drug-resistant bacteria with no systemic absorption and minimal renal toxicity.

Level of evidence:

2a

Nanomaterials for Delivering Antibiotics in the Therapy of Pneumonia

Bacterial pneumonia is one of the leading causes of death worldwide and exerts a significant burden on health-care resources. Antibiotics have long been used as first-line drugs for the treatment of bacterial pneumonia. However, antibiotic therapy and traditional antibiotic delivery are associated with important challenges, including drug resistance, low bioavailability, and adverse side effects; the existence of physiological barriers further hampers treatment. Fortunately, these limitations may be overcome by the application of nanotechnology, which can facilitate drug delivery while improving drug stability and bioavailability. This review summarizes the challenges facing the treatment of bacterial pneumonia and also highlights the types of nanoparticles that can be used for antibiotic delivery. This review places a special focus on the state-of-the-art in nanomaterial-based approaches to the delivery of antibiotics for the treatment of pneumonia.

Molecular mechanisms underlying the renal protective effects of coenzyme Q10 in acute kidney injury

Coenzyme Q10 (CoQ10), an endogenous antioxidant, has been reported frequently to exert an outstanding protective effect on multiple organ injury, including acute kidney injury (AKI). In this study, we aim to summarize all the current evidence of the protective action of CoQ10 against AKI as there are presently no relevant reviews in the literature. After a systematic search, 20 eligible studies, either clinical trials or experimental studies, were included and further reviewed. CoQ10 treatment exhibited a potent renal protective effect on various types of AKI, such as AKI induced by drugs (e.g., ochratoxin A, cisplatin, gentamicin, L-NAME, and nonsteroidal anti-inflammatory drug), extracorporeal shock wave lithotripsy (ESWL), sepsis, contrast media, and ischemia–reperfusion injury. The renal protective role of CoQ10 against AKI might be mediated by the antiperoxidative, anti-apoptotic, and anti-inflammatory potential of CoQ10. The molecular mechanisms for the protective effects of CoQ10 might be attributed to the regulation of multiple essential genes (e.g., caspase-3, p53, and PON1) and signaling cascades (e.g., Nrf2/HO-1 pathway). This review highlights that CoQ10 may be a potential strategy in the treatment of AKI.

Aminoglycosides use has a risk of acute kidney injury in patients without prior chronic kidney disease

The outcome of acute kidney injury (AKI) as a result of aminoglycosides (AGs) use remains uncertain in patients without prior chronic kidney disease (CKD). Therefore, we explored the outcomes of AGs use on AKI episodes associated with renal recovery and progress in patients without prior CKD in Taiwan. This was a retrospective cohort study by using the Taipei Medical University Research Database from January 2008 to December 2019. 43,259 individuals without CKD who had received parenteral AGs were enrolled. The exposed and unexposed groups underwent propensity score matching for age, gender, patients in intensive care unit/emergency admission, and covariates, except serum hemoglobin and albumin levels. We identified an exposed group of 40,547 patients who used AGs (median age, 54.4 years; 44.3% male) and an unexposed group of 40,547 patients without AG use (median age, 55.7 years; 45.5% male). There was the risk for AKI stage 1 (adjusted hazard ratio [HR] 1.34; 95% confidence interval [CI] 1.00-1.79; p = 0.05) in patients that used AGs in comparison with the control subjects. Moreover, patients using AGs were significantly associated neither with the progression to acute kidney disease (AKD) stages nor with the progression to end-stage renal disease (ESRD) on dialysis. Further analyzed, there was an increased risk of AKI episodes for serum albumin levels less than 3.0 g/dL and hemoglobin levels less than 11.6 g/dL. Among patients without prior CKD, AGs-used individuals were associated with AKI risks, especially those at relatively low albumin (< 3.0 g/dL) or low hemoglobin (< 11.6 g/dL). That could raise awareness of AGs prescription in those patients in clinical practice.

The Medium Composition Impacts Staphylococcus aureus Biofilm Formation and Susceptibility to Antibiotics Applied in the Treatment of Bone Infections

The biofilm-associated infections of bones are life-threatening diseases, requiring application of dedicated antibiotics in order to counteract the tissue damage and spread of microorganisms. The in vitro analyses on biofilm formation and susceptibility to antibiotics are frequently carried out using methods that do not reflect conditions at the site of infection. To evaluate the influence of nutrient accessibility on Staphylococcus aureus biofilm development in vitro, a cohesive set of analyses in three different compositional media was performed. Next, the efficacy of four antibiotics used in bone infection treatment, including gentamycin, ciprofloxacin, levofloxacin, and vancomycin, against staphylococcal biofilm, was also assessed. The results show a significant reduction in the ability of biofilm to grow in a medium containing elements occurring in the serum, which also translated into the diversified changes in the efficacy of used antibiotics, compared to the setting in which conventional media were applied. The differences indicate the need for implementation of adequate in vitro models that closely mimic the infection site. The results of the present research may be considered an essential step toward the development of in vitro analyses aiming to accurately indicate the most suitable antibiotic to be applied against biofilm-related infections of bones.

Protective effect of inhibiting necroptosis on gentamicin-induced nephrotoxicity

Necroptosis is defined as a novel programmed cell necrosis that is mediated by receptor interacting serine-threonine protein kinase 1 (RIPK1) and other related signals. Necrosis, apoptosis and inflammation are commonly considered as the leading mechanism in acute kidney injury (AKI) induced by gentamicin (GEN), which is a useful antibiotic for treating the infection of Gram-negative bacterial. However, the necroptosis in the pathogenesis of GEN-induced AKI is unknown. In this study, to investigate the process and function of necroptosis in GEN-induced AKI, NRK-52E and HK-2 cells and SD rats were used as the models. The necroptosis-related proteins, including RIPK1, RIPK3, mixed lineage kinase domain-like (MLKL) and phosphorylated MLKL (p-MLKL), were all increasing time-dependently when GEN was continuously given. By using the RIPK1 inhibitor necrostatin-1 (NEC-1) and RIPK3 inhibitor (CPD42), the GEN-induced toxicity of tubular cells was alleviated. Moreover, it was validated that GEN-induced cell apoptosis and inflammation were attenuated after treating with NEC-1 or CPD42, both in vivo and in vitro. When MLKL was knocked down by siRNA, NEC-1 and CPD42 can not further protect the damage of tubular cells by GEN. Although the using of pan-caspase inhibitor Z-VAD significantly decreased GEN-induced apoptosis, it enhanced necroptosis and slightly promoted the decreased cell viability in GEN-treated cells, with the protective effects weaker than NEC-1 or CPD42. Finally, in vitro minimum inhibitory concentration (MIC) tests and bacteriostatic ring studies showed that NEC-1 did not interfere with the antibiotic effects of GEN. Thus, suppressing necroptosis can serve as a promising strategy for the prevention of GEN-induced nephrotoxicity.

Investigation of Gentamicin Release from Polydopamine Nanoparticles

Polydopamine (PDA), being highly reactive in nature, has acquired great attention in multi-disciplinary fields. Owing to its fascinating properties, including its biocompatible, non-toxic and readily bio-degradative nature, we investigated the drug loading and release behavior, using an aminoglycoside antibiotic gentamicin (G) as a model drug. The gentamicin was loaded into the PDA nanoparticles (NPs) via an in situ polymerization method. The release kinetics of the gentamicin was then studied in pH 3, 5 and 7.4. Two batches with varied gentamicin loadings, G-PDA NPs 1:1 (with approx. 84.1% loaded gentamicin) and G-PDA NPs 0.6:1 (with approx. 72.7% loaded gentamicin), were studied. The drug release data were analyzed by LC–MS. The PDA showed good stability in terms of gentamicin release at alkaline pH over a period of seven days. The negative surface charge of PDA at pH 7.4 makes a strong bond with gentamicin, hence preventing its release from the PDA NPs. However, at pH 5 and 3, the amine groups of PDA are more prone towards protonation, making PDA positively charged, hence the repulsive forces caused the gentamicin to detach and release from the G-PDA NPs. Consequently, approx. 40% and 55% drug release were observed at pH 5 and 3, respectively, from the G-PDA NPs 1:1. However, the drug released from G-PDA NPs 0.6:1 was found to be one half as compared to the G-PDA NPs 1:1, which is obvious to the concentration gradient. These findings suggested that the in situ loading method for gentamicin could provide drug release over a period of seven days, hence defending the drug’s efficacy and safety challenges. Furthermore, two kinetic models, namely the Ritger–Peppas and Higuchi models, were implemented to determine the drug release kinetics. Curve fitting analysis supported our findings for the drug release kinetics which are followed by PDA structural changes in response to pH.

Cichoric Acid May Play a Role in Protecting Hair Cells from Ototoxic Drugs

Ototoxic hearing loss due to antibiotic medication including aminoglycosides and excess free radical production causes irreversible hair cell injury. Cichoric acid, a naturally occurring phenolic acid, has recently been found to exert anti-oxidative and anti-inflammatory properties through its free radical scavenging capacity. The present study aimed to investigate the protective effects of cichoric acid against neomycin-induced ototoxicity using transgenic zebrafish (pvalb3b: TagGFP). Our results indicated that cichoric acid in concentrations up to 5 μM did not affect zebrafish viability during the 2 h treatment period. Therefore, the otoprotective concentration of cichoric acid was identified as 5 μM under 2 h treatment by counting viable hair cells within the neuromasts of the anterior- and posterior-lateral lines in the study. Pretreatment of transgenic zebrafish with 5 μM of cichoric acid for 2 h significantly protected against neomycin-induced hair cell death. Protection mediated by cichoric acid was, however, lost over time. A terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and FM4-64 staining, respectively, provided in situ evidence that cichoric acid ameliorated apoptotic signals and mechanotransduction machinery impairment caused by neomycin. A fish locomotor test (distance move, velocity, and rotation frequency) assessing behavioral alteration after ototoxic damage revealed rescue due to cichoric acid pretreatment before neomycin exposure. These findings suggest that cichoric acid in 5 μM under 2 h treatment has antioxidant effects and can attenuate neomycin-induced hair cell death in neuromasts. Although cichoric acid offered otoprotection, there is only a small difference between pharmacological and toxic concentrations, and hence cichoric acid can be considered a rather prototypical compound for the development of safer otoprotective compounds.

Potential of Continuous Local Antibiotic Perfusion Therapy for Fracture-Related Infections

Introduction

Fracture-related infections (FRIs) are challenging for orthopedic surgeons, as conventional surgical treatment and systemic antimicrobial therapy cannot completely control local infections. Continuous local antibiotic perfusion (CLAP) is a novel and innovative therapy for bone and soft-tissue infections, and is expected to eradicate biofilms by maintaining a sustained high concentration of antimicrobial agents at the infected site. If CLAP therapy can eradicate infection even in cases with implants while preserving the implants, it would be an ideal and effective treatment for local refractory infections. This study aimed to evaluate the usefulness of novel CLAP therapy for FRIs.

Methods

Nine patients treated with CLAP therapy were retrospectively analyzed. The mean age was 65.9 (43–82) years, and the mean follow-up period was 14.9 (6–45) months. In all cases, the infected sites were related to the lower extremities (tibia, n = 6; fibula, n = 1; hip joint, n = 1; foot, n = 1). All patients underwent similar procedures for this therapy combined with negative-pressure wound therapy after thorough irrigation and debridement of infected tissues.

Results

The pathogens identified were Staphylococcus aureus (methicillin-resistant S. aureus, n = 5; methicillin-susceptible S. aureus, n = 1), Pseudomonas aeruginosa (n = 3), Enterococcus faecalis (n = 2), Corynebacterium (n = 1), and Enterobacter (n = 1); pathogens were not detected in one case. The mean duration of CLAP was 17.0 (7–35) days. In all cases, implants were preserved until bone union was achieved. Five cases relapsed; however, infection was finally suppressed in all cases by repeating this method. No side effects were observed.

Conclusion

This novel case series presents treatment outcomes using CLAP therapy for FRIs. This method has the potential to control the infection without removing the implants, because of the sustained high concentration of antimicrobial agents at the infected site, and could be a valuable treatment option for refractory FRIs with implants, in which bone union has not been achieved.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00653-5.

Predictive value of two different definitions of contrast-associated acute kidney injury for long-term major adverse kidney events in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

It remains controversial whether contrast-associated acute kidney injury (CA-AKI) is associated with long-term major adverse kidney events (MAKE) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

METHODS

By the Acute Kidney Injury Network (AKIN) criteria, CA-AKI was defined as an increase in serum creatinine ≥ 0.3 mg/dL or 50% from baseline within 48 h after PCI; or an increase in serum creatinine ≥ 0.5 mg/dL or 25% within 72 h by the contrast-induced nephropathy (CIN) criteria. The primary endpoint was 1-year MAKE, defined as a composite of all-cause mortality and persistent renal dysfunction.

RESULTS

A total of 402 patients were finally included in this study. The primary endpoint occurred in 29 (7.2%) patients. There was a significant association between CA-AKI and 1-year MAKE assessed by both the AKIN (hazard ratios [HR]: 11.58, 95% confidence interval [CI]: 4.29-31.24, p = 0.000) and CIN (HR: 6.45, 95% CI: 2.56-16.25, p = 0.000) definitions. However, the AKIN definition (HR: 4.95, 95% CI: 1.17-21.02, p = 0.030) was more reliable in the prediction of persistent renal dysfunction than CIN definition (HR: 4.08, 95% CI: 0.99-16.87, p = 0.052). Additionally, the area under receiver operating characteristic curve was larger for predicting 1-year MAKE with the AKIN definition than CIN definition (0.742 vs. 0.727).

CONCLUSIONS

In patients with STEMI undergoing primary PCI, CA-AKI was significantly associated with 1-year MAKE. Moreover, the AKIN definition might be more reliable in the prediction of long-term prognosis.

Therapeutic Strategies for Dystrophin Replacement in Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is an X-linked hereditary disease characterized by progressive muscle wasting due to modifications in the DMD gene (exon deletions, nonsense mutations, intra-exonic insertions or deletions, exon duplications, splice site defects, and deep intronic mutations) that result in a lack of functional dystrophin expression. Many therapeutic approaches have so far been attempted to induce dystrophin expression and improve the patient phenotype. In this manuscript, we describe the relevant updates for some therapeutic strategies for DMD aiming to restore dystrophin expression. We also present and analyze in vitro and in vivo ongoing experimental approaches to treat the disease.

Factores asociados a infección de vías urinarias luego de una prostatectomía

Introducción y Objetivo La cirugía de próstata es un procedimiento frecuente en varones mayores. Existen diferentes técnicas, cuya elección depende de la patología a tratar, de la experiencia del especialista, y de la disponibilidad técnica. Entre sus complicaciones se encuentra la infección del tracto urinario, que ocasiona incremento en morbimortalidad y costos para el sistema de salud. El objetivo principal de este estudio fue evaluar los factores relacionados con la aparición de infección urinaria luego de este tipo de cirugía.

Materiales y Métodos Se realizó un estudio de casos y controles en una población de pacientes sometidos a prostatectomía del 2018 hasta principios del 2020 en Medellín, Colombia. Los casos correspondieron a los pacientes que presentaron infección de vías urinarias hasta 30 días tras la prostatectomía. Se estimó la asociación entre casos y controles por medio del cálculo de la razón de disparidad (RD), la cual se ajustó con una regresión logística y con un modelo aditivo generalizado multivariado.

Resultados Se identificaron 96 casos incidentes de infección del trato urinario luego de la prostatectomía, con una prevalencia de 8.99%. La frecuencia de solicitud de urocultivo preoperatorio fue de 52,92% (intervalo de confianza del 95% [IC95%]: 48,34–57,44%). Las variables independientemente asociadas con la aparición de infección urinaria fueron: solicitud de urocultivo prequirúrgico, número de dosis, y tipo de antibiótico usado para la profilaxis. Particularmente, se encontró como factor protector el uso de aminoglucósidos. En los pacientes con infección urinaria, los principales gérmenes aislados fueron: Eschirichia coli, Pseudomonas aeruginosa, Klepsiella pneumoniae, Enterococos faecalis y Serratia marcescens.

Conclusión Este estudio demuestra que factores como la solicitud preoperatoria de urocultivo y el uso de aminoglucósidos en los esquemas de profilaxis quirúrgica reducen la probabilidad de desarrollar una infección urinaria luego de una prostatectomía.

Thymol exerts antioxidant, anti-inflammatory, and anti-apoptotic protective effects against gentamicin nephrotoxicity in rats

The renoprotective effect of thymol (TML) was investigated in rats challenged with gentamicin (GN). Rats received TML (20 mg/kg/day, p.o.) for 15 days, and GN (80 mg/kg/day, i.p.) starting from the 8th day. TML significantly lowered serum creatinine and neutrophil gelatinase-associated lipocalin, and renal malondialdehyde, nitric oxide, tumor necrosis factor-α, interleukin-18, Bax, caspase-3, and caspase-9 in GN-challenged rats. In addition, TML caused a significant increment of renal total antioxidant capacity in rats received GN. Moreover, TML significantly ameliorated GN-induced histopathological kidney tissue injury, and significantly decreased nuclear factor-κB p65 and kidney injury molecule-1 expressions in kidneys of GN-challenged rats. It was concluded that TML guarded against CN-induced nephrotoxicity in rats via inhibition of oxidative stress, inflammation, and apoptosis.

Isolation and Characterization of a Novel Autographiviridae Phage and Its Combined Effect with Tigecycline in Controlling Multidrug-Resistant Acinetobacter baumannii-Associated Skin and Soft Tissue Infections

Multidrug-resistant Acinetobacter baumannii (MDR A. baumannii) is one of the ESKAPE pathogens that restricts available treatment options. MDR A. baumannii is responsible for a dramatic increase in case numbers of a wide variety of infections, including skin and soft tissue infections (SSTIs), resulting in pyoderma, surgical debridement, and necrotizing fasciitis. To investigate an alternative medical treatment for SSTIs, a broad range lytic Acinetobacter phage, vB _AbP_ABWU2101 (phage vABWU2101), for lysing MDR A. baumannii in associated SSTIs was isolated and the biological aspects of this phage were investigated. Morphological characterization and genomic analysis revealed that phage vABWU2101 was a new species in the Friunavirus, Beijerinckvirinae, family Autographiviridae, and order Caudovirales. Antibiofilm activity of phage vABWU2101 demonstrated good activity against both preformed biofilms and biofilm formation. The combination of phage vABWU2101 and tigecycline showed synergistic antimicrobial activities against planktonic and biofilm cells. Scanning electron microscopy confirmed that the antibacterial efficacy of the combination of phage vABWU2101 and tigecycline was more effective than the phage or antibiotic alone. Hence, our findings could potentially be used to develop a therapeutic option for the treatment of SSTIs caused by MDR A. baumannii.

Bronchiectasis and inhaled tobramycin: A literature review

BACKGROUND

Inhaled antibiotics have been incorporated into contemporary European and British guidelines for bronchiectasis, yet no inhaled antibiotics have been approved in the United States or Europe for the treatment of bronchiectasis not related to cystic fibrosis. Pseudomonas aeruginosa infection is common in patients with bronchiectasis, contributing to a cycle of progressive inflammation, exacerbations, and airway remodelling.

OBJECTIVE

The aim of the current study was to identify and evaluate published studies of inhaled tobramycin solution or powder in patients with bronchiectasis and P. aeruginosa infection not associated with cystic fibrosis.

METHODS

A literature review was conducted utilising the PubMed and Cochrane databases. Studies published in the English language that reported safety and/or efficacy outcomes of inhaled tobramycin either alone or in combination with other antibiotics were included.

RESULTS

Seven clinical trials published between 1999 and 2021 were identified that met inclusion criteria. Inhaled tobramycin therapy was effective in reducing P. aeruginosa microbial density in the sputum of patients with bronchiectasis. Several studies demonstrated favourable impacts on hospitalisations, number and severity of exacerbations, and symptoms. Other studies were underpowered for these clinical outcomes or were exploratory in nature. Although tobramycin was generally well tolerated, some evidence of treatment-associated wheezing was reported.

CONCLUSIONS

In patients with bronchiectasis and chronic P. aeruginosa infection, inhaled tobramycin was effective in reducing the density of bacteria in sputum, which may be associated with additional clinical benefits. Definitive phase 3 trials of inhaled tobramycin in patients with bronchiectasis are indicated to determine clinical efficacy and long-term safety.

Drug Therapies Affecting Renal Function: An Overview

Undesirable side effects of medication are inevitable. Due to the role of the kidneys in clearance and filtration, the renal system faces a unique situation when it comes to the side effects of drugs. It has an important role for different classes of drugs to be excreted, and drugs are a key factor for this system to be at risk. Medications in articles were divided into classes using the standard set by the Saudi Pharmaceutical Journal. Many drug classes cause renal insults. The top six classes were pain killers, antibiotics, proton pump inhibitors, antidiabetics, antihyperlipidemics, and agents for erectile dysfunction. Renal insults caused by these agents could vary in severity. Some drugs could cause nephrotoxicity from one dose, while others may only need continuous monitoring. Different populations also operate under different rules, as some people need dose adjustments while others who are medically free of major illnesses do not. A variety of unfavorable outcomes for the kidney could take place, such as acute kidney injury, chronic kidney disease, and end-stage renal disease, and unfortunately, some of these issues could lead to the need for renal replacement therapies. The outcome of this review paper will help multidisciplinary physicians to understand the renal side effects of the most used drug classes in the Kingdom of Saudi Arabia, their destructive mechanisms, and most importantly, the clinical presentations of renal dysfunction in relation to each class. Emphasizing these adverse effects will prevent future unfavorable outcomes, especially in commonly used drugs that are frequently prescribed for different age groups. Moreover, some of these drugs are considered to be over-the-counter medications, which makes them a serious problem that needs to be handled cautiously.

Risk of antimicrobial-associated organ injury among the older adults: a systematic review and meta-analysis

Background

Older adults (aged 65 years and above) constitute the fastest growing population cohort in the western world. There is increasing evidence that the burden of infections disproportionately affects older adults, and hence this vulnerable population is frequently exposed to antimicrobials. There is currently no systematic review summarising the evidence for organ injury risk among older adults following antimicrobial exposure. This systematic review and meta-analysis examined the relationship between antimicrobial exposure and organ injury in older adults.

Methodology

We searched for original research articles in PubMed, Embase.com, Web of Science core collection, Web of Science BIOSIS citation index, Scopus, Cochrane Central Register of Controlled Trials, ProQuest, and PsycINFO databases, using key words in titles and abstracts, and using MeSH terms. We searched for all available articles up to 31 May 2021. After removing duplicates, articles were screened for inclusion into or exclusion from the study by two reviewers. The Newcastle-Ottawa scale was used to assess the risk of bias for cohort and case-control studies. We explored the heterogeneity of the included studies using the Q test and I² test and the publication bias using the funnel plot and Egger’s test. The meta-analyses were performed using the OpenMetaAnalyst software.

Results

The overall absolute risks of acute kidney injury among older adults prescribed aminoglycosides, glycopeptides, and macrolides were 15.1% (95% CI: 12.8–17.3), 19.1% (95% CI: 15.4–22.7), and 0.3% (95% CI: 0.3–0.3), respectively. Only 3 studies reported antimicrobial associated drug-induced liver injury. Studies reporting on the association of organ injury and antimicrobial exposure by age or duration of treatment were too few to meta-analyse. The funnel plot and Egger’s tests did not indicate evidence of publication bias.

Conclusion

Older adults have a significantly higher risk of sustaining acute kidney injury when compared to the general adult population. Older adults prescribed aminoglycosides have a similar risk of acute kidney injury to the general adult population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02512-3.

Protective Effects of Descurainia sophia against Gentamicin Induced Nephrotoxicity in Rats

Several studies have tried to find an efficient agent to prevent or reverse gentamicin (Gm) induced acute kidney injury (AKI). In this study, we assessed the potential renal protective effects of Descurainia sophia (L.) Webb ex Prantl against Gm-induced nephrotoxicity in rats. Thirty-five male Wistar rats were categorized in five groups (n = 7 per group). Control group was treated with normal saline. In four experimental groups, the rats were initially treated with normal saline (A), 800 (B), 1600 (C) and 2400 (D) mg/kg Descurainia sophia respectively for 28 days. After that, the rats of experimental groups were treated with Gm (80 mg/Kg) for 7 consecutive days. Blood and urine markers, as well as apoptosis and histological features were determined. Serum BUN, creatinine, cholesterol, and triglycerides level, as well as urinary excretion of Na⁺ significantly increased in group A. Furthermore, Gm induced inflammatory cells infiltration, apoptosis, and renal cells injuries in rats were pretreated with normal saline (group A). However, in the rats pretreated with Descurainia sophia extract (groups B, C, and D, there were significant and dose-dependent reductions in serum BUN, creatinine, cholesterol and triglyceride, urinary Na⁺ excretion, apoptosis rate, and inflammatory cells infiltration in renal tissues. Overall, Descurainia sophia showed significant protective effects against Gm-induced AKI by alleviating biochemical and histological markers of renal toxicity.

Daphnetin ameliorated GM-induced renal injury through the suppression of oxidative stress and apoptosis in mice

Gentamicin (GM), an aminoglycoside antibiotic, is one of the most effective drugs used in the treatment of various types of bacterial infections, but the major adverse effect and drug-induced nephrotoxicity of GM limit its clinical applications. Daphnetin (Daph) is a natural coumarin derivative that is clinically used to treat rheumatoid arthritis and coagulopathy and exhibits antioxidant effects. However, the effect of Daph on GM-induced nephrotoxicity has not yet been elucidated. This study investigated Daph-mediated protection against GM-induced nephrotoxicity in mice and explored the underlying mechanisms of GM-induced renal dysfunction in mice. We found that Daph treatment significantly reduced GM-induced nephrotoxicity mainly by ameliorating renal injury in mice and attenuating cell damage in vitro. Mechanistically, we found that Daph upregulated the expression level of Nrf2 and its regulated antioxidant enzymes HO-1, NQO1, GCLC and GCLM in vivo and in vitro. GM upregulated the expression levels of NOX4, cleaved Caspase-3 and p53 and the BAX/BCL2 ratio in vivo to stimulate oxidative stress and apoptosis. However, Daph treatment significantly improved the oxidative stress and apoptosis caused by GM, thereby exerting antioxidative and antiapoptotic effects. Our study was the first to suggest that the natural product Daph protects against GM-induced nephrotoxicity through the activation of Nrf2 which regulates oxidative stress and apoptosis. The pharmacological activation of Nrf2 may be useful as a novel therapy to prevent renal injury.

Review of the Applications of Biomedical Compositions Containing Hydroxyapatite and Collagen Modified by Bioactive Components

Regenerative medicine is becoming a rapidly evolving technique in today’s biomedical progress scenario. Scientists around the world suggest the use of naturally synthesized biomaterials to repair and heal damaged cells. Hydroxyapatite (HAp) has the potential to replace drugs in biomedical engineering and regenerative drugs. HAp is easily biodegradable, biocompatible, and correlated with macromolecules, which facilitates their incorporation into inorganic materials. This review article provides extensive knowledge on HAp and collagen-containing compositions modified with drugs, bioactive components, metals, and selected nanoparticles. Such compositions consisting of HAp and collagen modified with various additives are used in a variety of biomedical applications such as bone tissue engineering, vascular transplantation, cartilage, and other implantable biomedical devices.

The msaABCR Operon Regulates Persister Formation by Modulating Energy Metabolism in Staphylococcus aureus

Staphylococcus aureus is a major human pathogen that causes chronic, systemic infections, and the recalcitrance of these infections is mainly due to the presence of persister cells, which are a bacterial subpopulation that exhibits extreme, yet transient, antibiotic tolerance accompanied by a transient halt in growth. However, upon cessation of antibiotic treatment, a resumption in growth of persister cells causes recurrence of infections and treatment failure. Previously, we reported the involvement of msaABCR in several important staphylococcal phenotypes, including the formation of persister cells. Additionally, observations of the regulation of several metabolic genes by the msaABCR operon in transcriptomics and proteomics analyses have suggested its role in the metabolic activities of S. aureus. Given the importance of metabolism in persister formation as our starting point, in this study we demonstrated how the msaABCR operon regulates energy metabolism and subsequent antibiotic tolerance. We showed that deletion of the msaABCR operon results in increased tricarboxylic acid (TCA) cycle activity, accompanied by increased cellular ATP content and higher NADH content in S. aureus cells. We also showed that msaABCR (through MsaB) represses the ccpE and ndh₂ genes, thereby regulating TCA cycle activity and the generation of membrane potential, respectively. Together, the observations from this study led to the conclusion that msaABCR operon deletion induces a metabolically hyperactive state, leading to decreased persister formation in S. aureus.

Improving the Inhibitory Effect of Phages against Pseudomonas aeruginosa Isolated from a Burn Patient Using a Combination of Phages and Antibiotics

Antibiotic resistance causes around 700,000 deaths a year worldwide. Without immediate action, we are fast approaching a post-antibiotic era in which common infections can result in death. Pseudomonas aeruginosa is the leading cause of nosocomial infection and is also one of the three bacterial pathogens in the WHO list of priority bacteria for developing new antibiotics against. A viable alternative to antibiotics is to use phages, which are bacterial viruses. Yet, the isolation of phages that efficiently kill their target bacteria has proven difficult. Using a combination of phages and antibiotics might increase treatment efficacy and prevent the development of resistance against phages and/or antibiotics, as evidenced by previous studies. Here, in vitro populations of a Pseudomonas aeruginosa strain isolated from a burn patient were treated with a single phage, a mixture of two phages (used simultaneously and sequentially), and the combination of phages and antibiotics (at sub-minimum inhibitory concentration (MIC) and MIC levels). In addition, we tested the stability of these phages at different temperatures, pH values, and in two burn ointments. Our results show that the two-phages-one-antibiotic combination had the highest killing efficiency against the P. aeruginosa strain. The phages tested showed low stability at high temperatures, acidic pH values, and in the two ointments. This work provides additional support for the potential of using combinations of phage-antibiotic cocktails at sub-MIC levels for the treatment of multidrug-resistant P. aeruginosa infections.

Nanomedicine for Gene Delivery and Drug Repurposing in the Treatment of Muscular Dystrophies

Muscular Dystrophies (MDs) are a group of rare inherited genetic muscular pathologies encompassing a variety of clinical phenotypes, gene mutations and mechanisms of disease. MDs undergo progressive skeletal muscle degeneration causing severe health problems that lead to poor life quality, disability and premature death. There are no available therapies to counteract the causes of these diseases and conventional treatments are administered only to mitigate symptoms. Recent understanding on the pathogenetic mechanisms allowed the development of novel therapeutic strategies based on gene therapy, genome editing CRISPR/Cas9 and drug repurposing approaches. Despite the therapeutic potential of these treatments, once the actives are administered, their instability, susceptibility to degradation and toxicity limit their applications. In this frame, the design of delivery strategies based on nanomedicines holds great promise for MD treatments. This review focuses on nanomedicine approaches able to encapsulate therapeutic agents such as small chemical molecules and oligonucleotides to target the most common MDs such as Duchenne Muscular Dystrophy and the Myotonic Dystrophies. The challenge related to in vitro and in vivo testing of nanosystems in appropriate animal models is also addressed. Finally, the most promising nanomedicine-based strategies are highlighted and a critical view in future developments of nanomedicine for neuromuscular diseases is provided.

Inhibitors of Eukaryotic Translational Machinery as Therapeutic Agents

Inhibiting eukaryotic protein translation with small molecules is emerging as a powerful therapeutic strategy. The advantage of targeting cellular translational machinery is that it is required for the highly proliferative state of many neoplastic cells, replication of certain viruses, and ultimately the expression of a wide variety of protein targets. Although, this approach has been exploited to develop clinical agents, such as homoharringtonine (HHT, 1), used to treat chronic myeloid leukemia (CML), inhibiting components of the translational machinery is often associated with cytotoxic phenotypes. However, recent studies have demonstrated that certain small molecules can inhibit the translation of specific subsets of proteins, leading to lower cytotoxicity, and opening-up therapeutic opportunities for translation inhibitors to be deployed in indications beyond oncology and infectious disease. This review summarizes efforts to develop inhibitors of the eukaryotic translational machinery as therapeutic agents and highlights emerging opportunities for translation inhibitors in the future.

Human umbilical cord blood serum attenuates gentamicin-induced liver toxicity by restoring peripheral oxidative damage and inflammation in rats

Gentamicin (GM) is an aminoglycoside antibiotic that despite its antibacterial effects, its use is restricted due to numerous side effects. The umbilical cord serum contains various biomolecules that have protective impacts on the damaged tissues. The aim of this study was to gauge the protective effect of human umbilical cord blood serum (hUCBS) on GM-induced hepatotoxicity. In this experimental study, 28 male Wistar rats, weighing 220 ± 20 g, were randomly categorized into 4 groups including control, GM (100 mg/kg), hUCBS at doses of 1 and 2% along with GM (100 mg/kg) for 10 days, intraperitoneally. Twenty-four hours after the last injection, direct blood sampling was taken from the heart to obtain blood serum and liver enzymes, inflammatory cytokines and liver tissue were examined for histology. GM causes necrosis and inflammation in liver tissue. Liver enzyme and inflammatory cytokine levels were significantly increased in the GM group. Human umbilical cord blood serum significantly decreased liver enzyme and inflammatory cytokines levels in the experimental groups compared to the GM group. GM causes liver damage such as the inflammation and necrosis in liver tissue. Treating the animals with hUCBS reduced the toxic effects of GM in the liver.

Guideline-Discordant Preoperative Gentamicin Dosing and the Risk of Gentamicin Associated Nephrotoxicity in Urologic Surgery

OBJECTIVE

To determine the rate of and predictors for guideline-discordant preoperative gentamicin dosing in urologic surgery and to assess the risk of nephrotoxicity in patients who receive the recommended high-dose prophylaxis.

MATERIALS AND METHODS

We retrospectively reviewed all adult patients who received preoperative gentamicin for urologic surgery from January 1, 2017 - October 3, 2019. Doses were categorized as guideline-concordant or -discordant using a cutoff of 4.5 mg/kg dosing weight. We used multivariable logistic regression to identify predictors for guideline-discordant dosing. Postoperative kidney injury was assessed using RIFLE criteria.

RESULTS

Among 2134 patients, 89% received a preoperative dose ≤ 4.5 mg/kg. Older age (70+ years) and endoscopic surgery were significant risk factors for guideline-discordant dosing (OR 2.54, P< 0.001; OR 6.21, P<0.001). Among 735 patients with complete data, there was no significant difference in the risk of kidney injury between those who received a dose less than 4.5 mg/kg and those who received a higher dose (OR 0.89, 95% CI: 0.26 - 2.99, P = 0.75).

CONCLUSION

Preoperative gentamicin is commonly administered at lower than recommended doses for urologic surgery. Older age and endoscopic surgery are significant predictors of guideline-discordant dosing. The risk of kidney injury following high-dose preoperative gentamicin for urologic procedures is likely comparable to the risk at lower doses.