Biodesulfurization of dibenzothiophene by Shewanella putrefaciens NCIMB 8768

The desulfurization ability of Shewanella putrefaciens strain NCIMB 8768 was studied and its activity profile was compared with the widely studied strain Rhodococcus erythropolis strain IGTS8. Dibenzothiophene (DBT) is a recalcitrant thiophenic component of fossil fuels especially among diesel blend stocks. DBT in basic salt medium (BSM) at a final concentration of 0.3, 0.6 and 0.9 mM was supplied to the microbes as the sole sulfur source. Experimental results showed that S. putrefaciens, similar to other biodesulfurization organisms, converted DBT to the end product 2-hydroxybiphenyl (HBP), as detected by the Gibbs assay and HPLC. Cells cultivated in medium containing 0.3 mM of DBT showed the highest desulfurization activity, with a maximum specific production rate 43.5 mmol/L of HBP

Clinical implications of chloroquine and hydroxychloroquine ototoxicity for COVID-19 treatment: A mini-review

At this time of the COVID-19 pandemic, potentially effective treatments are currently under urgent investigation. Benefits of chloroquine and hydroxychloroquine for the treatment of COVID-19 infection have been proposed and clinical trials are underway. Chloroquine and hydroxychloroquine, typically used for the treatment of malaria and autoimmune diseases, have been considered for off-label use in several countries. In the literature, there are reports of ototoxic effects of the drugs causing damage to the inner ear structures, which then result in hearing loss, tinnitus, and/or imbalance. This mini-review represents a summary of the findings from a systematic search regarding ototoxicity of chloroquine and hydroxychloroquine in the published literature. The characteristics of sensorineural hearing loss and/or tinnitus after chloroquine or hydroxychloroquine treatment can be temporary but reports of persistent auditory and vestibular dysfunction exist. These are not frequent, but the impact can be substantial. Additionally, abnormal cochleovestibular development in the newborn was also reported after chloroquine treatment in pregnant women. The suggested dose of chloroquine for COVID-19 infection is considerably higher than the usual dosage for malaria treatment; therefore, it is plausible that the ototoxic effects will be greater. There are potential implications from this review for survivors of COVID-19 treated with chloroquine or hydroxychloroquine. Patient reports of hearing loss, tinnitus, or imbalance should be noted. Those with troublesome hearing loss, tinnitus and/or imbalance are encouraged to be referred for hearing evaluation and interventions once they are stable. Clinical trials of chloroquine or hydroxychloroquine should also consider including audiological monitoring in the protocol

Looking beyond the audiogram in ototoxicity associated with platinum-based chemotherapy

© 2019, The Author(s). Introduction: Ototoxicity associated with platinum-based chemotherapy is highly prevalent and can cause detrimental consequences among cancer survivors. Discussion: In this article, we highlight important aspects of the evaluation of ototoxicity with the aim to increase awareness of Oncologists in this regard. Standard pure tone audiometry alone is inadequate for this context. Comprehensive and consistent hearing tests should be implemented in a monitoring and surveillance program. High-frequency audiometry (10–16kHz) is a sensitive tool in the detection of ototoxic hearing loss at onset. In addition to threshold audiometry, measures of speech comprehension (both in quiet and in noise) can add useful information in the evaluation of hearing in real-life situations. Not only hearing loss, but also tinnitus and imbalance are common in patients who receive platinum-based chemotherapy, and can cause debilitating effects upon quality of life in this population. Moreover, self-report measures associated with cochlear and vestibular handicaps can provide valuable information regarding the impact of ototoxicity. Conclusions: It is vital to build awareness about the variety and impact of the symptoms of ototoxicity. Comprehensive evaluation of hearing status along with self-reported impact of the cochlear and vestibular handicap should be implemented in a monitoring and surveillance program for appropriate investigation and management

Audiovestibular clinician experiences and opinions about cisplatin vestibulotoxicity

PurposeVestibulotoxicity associated with cisplatin chemotherapy is known to exist, but the extent, severity, and impact is unclear from the literature. This study explored knowledge, experiences, and opinions of audiovestibular professionals about cisplatin vestibulotoxicity.MethodsAn online survey was disseminated to clinicians working in the audiovestibular field.ResultsNinety-three respondents participated in the survey. Most professionals were aware of potential vestibulotoxicity associated with cisplatin chemotherapy. Thirty-three percent of the respondents reported that they had seen patients with cisplatin vestibulotoxicity. Forty percent of them were confident in making the diagnosis and in managing the patient in this situation. The prevalence and impact of vestibulotoxicity including practicality of the assessment should be considered when designing an effective vestibulotoxicity screening protocol.ConclusionThis study provides a better understanding of cisplatin vestibulotoxicity from the perspectives of audiovestibular clinicians, which will underpin appropriate detection and management of the condition

Preferential cochleotoxicity of cisplatin

Cisplatin-induced ototoxicity in humans is more predominant in the cochlea than in the vestibule. Neither definite nor substantial vestibular dysfunction after cisplatin treatment has been consistently reported in the current literature. Inner ear hair cells seem to have intrinsic characteristics that make them susceptible to direct exposure to cisplatin. The existing literature suggests, however, that cisplatin might have different patterns of drug trafficking across the blood-labyrinth-barrier, or different degrees of cisplatin uptake to the hair cells in the cochlear and vestibular compartments. This review proposes an explanation for the preferential cochleotoxicity of cisplatin based on current evidence as well as the anatomy and physiology of the inner ear. The endocochlear potential, generated by the stria vascularis, acting as the driving force for hair cell mechanoelectrical transduction might also augment cisplatin entry into cochlear hair cells. Better understanding of the stria vascularis might shed new light on cochleotoxic mechanisms and inform the development of otoprotective interventions to moderate cisplatin associated ototoxicity

Vestibulotoxicity Associated With Platinum-Based Chemotherapy in Survivors of Cancer: A Scoping Review

Background: Cochleotoxicity following the treatment with platinum-based chemotherapy is well documented. The potential for vestibulotoxicity is still unclear. This scoping review examined the extent of current research literature, summarized research findings and identified research gaps regarding vestibular-related adverse effects associated with platinum-based chemotherapy in survivors of cancer.Methods: Inclusion criteria followed the PICO principles: Participants, adult, and pediatric cancer patients of any cancer type; Intervention, platinum-based chemotherapy (such as cisplatin, carboplatin, and oxaliplatin); Control, none or any; Outcomes, vestibular-related adverse effects. English language articles published since 1978 were retrieved. Seventy-five eligible studies were identified from a systematic literature search, and relevant data were charted, collated, and summarized.Results: Testing for vestibulotoxicity predominately featured functional evaluation of the horizontal semicircular canal using the caloric and rotational tests. The rate of abnormal vestibular function test results after chemotherapy administration varied from 0 to 50%. The results of objective testing did not always correspond to patient symptoms. There is tentative support for patients with pre-existing loss of vestibular function to be more likely to experience vestibular toxicity after dosing with cisplatin.Conclusions: A number of studies reported significant evidence of vestibular toxicities associated with platinum-based chemotherapy, especially cisplatin. This scoping review emphasizes that vestibular toxicity needs more attention and comprehensive evaluation. Specifically, studies that analyse cumulative dose of platinum-based chemotherapy, affected sites of lesion in vestibular end organs, and the correlation and temporal patterns of cochlear and vestibular toxicity are needed

Biodesulphurisation of coal

The emission of sulphur oxides during the combustion of coal is one of the causes of an environmental problem known as acid rain. Biodesulphurisation technology applied as a method to remove sulphur before coal combustion was investigated in this work. The desulphurisation abilities of three specific bacterial strains including Rhodococcus erythropolis IGTS8, R. erythropolis X309 and Shewanella putrefaciens strain NCIMB 8768 have been evaluated. R. erythropolis IGTS8 and X309 were found to be able to remove both inorganic and organic sulphur from model compounds and coal samples. Their abilities to remove sulphur from benzothiophene were observed for the first time. A novel desulphurising bacterium, S. putrefaciens was also found to be able to remove inorganic and organic sulphur from coal samples. The bacterium, however, lost its ability to remove organic sulphur from model compounds during the investigation. R. erythropolis IGTS8 presented the greatest desulphurisation efficiency among the three bacterial strains. Nevertheless, the desulphurisation activity of R. erythropolis IGTS8 was too low for an economical coal biodesulphurisation process as it removed only 32.0% of total sulphur in bituminous coal, and 21.1% of total sulphur in anthracite coal. Alternatively, coal biodesulphurisation can be carried out in inexpensive conditions by using the bacteria inherent in the coal itself. The type of coal has an important effect on desulphurisation efficiency since the sulphur reduction in bituminous coal, which is in a lower rank than anthracite, was greater than the sulphur reduction in anthracite coal. This work also developed and evaluated the analytical methods used in the field. A HPLC method was developed to detect the desulphurisation metabolites of model compounds. The techniques for measuring sulphur in coal were improved

Vestibulotoxicity and balance problems associated with cisplatin chemotherapy in adult cancer survivors

Introduction and aims Cisplatin is an effective chemotherapeutic agent, but it has common side effects of ototoxicity and peripheral neuropathy which could potentially lead to balance problems. While cisplatin cochleotoxicity (causing hearing loss or tinnitus) is well documented, vestibulotoxicity (causing balance problems) is still unclear in literature. This thesis aimed to examine vestibular dysfunction and balance problems associated with cisplatin chemotherapy in adult cancer survivors to determine the epidemiology and impact of the problems. The project consists of 4 original research studies to evaluate the problems from patients and healthcare professional perspectives. Specific objectives of the studies were I. To examine current evidence and identify research gaps on vestibulotoxicity associated with cisplatin chemotherapy II. To explore knowledge, experiences, and opinions of audiovestibular professionals about cisplatin vestibulotoxicity III. To assess the vestibular function and balance problems in adult cancer survivors who had completed cisplatin chemotherapy treatment IV. To explore the lived experience and attitudes towards balance problems in adult cancer survivors who had completed cisplatin chemotherapy treatment Methods Scoping review: Research studies that mentioned vestibulotoxicity of cisplatin chemotherapy was identified through systematic literature search. Two researchers independently assessed and extracted data. Research findings were summarized narratively and research gaps were identified. Online survey: A questionnaire was developed to answer the specific research questions. Ninety-three clinicians working in the audiovestibular field participated in the online survey. Descriptive statistical analysis was conducted. Cross-sectional study: Sixty-five cancer survivors who had completed cisplatin treatment were recruited. The video Head Impulse Test (vHIT) of all semicircular canals was performed. Patient-reported balance symptoms were evaluated by a semi-structured clinical interview. Patients underwent bedside clinical tests including Dynamic Visual Acuity (DVA) test, Modified Clinical Testing of Sensory Interaction and Balance (CTSIB-m), and vibration sense testing to detect peripheral neuropathy. Descriptive and logistic regression statistical analyses were conducted. Interview study: Nine cancer survivors who had balance problems after chemotherapy treatment were interviewed. The interviews were transcribed, and analysed using inductive thematic analysis. Results Scoping review: Testing for cisplatin vestibulotoxicity predominately featured functional evaluation of the horizontal semicircular canal using the caloric and rotational tests. The rate of abnormal vestibular function test results after cisplatin treatment varied from 0 to 50%. The results of objective testing did not always correspond to patient symptoms. Online survey: Most of the audiovestibular professionals (87%) were aware of potential vestibulotoxicity associated with cisplatin chemotherapy, and some (31%) had seen patients with the condition. Forty percent of them were confident in making the diagnosis and in managing the patient in this situation. Cross-sectional study: All patients had normal vHIT results in all semicircular canals. Eleven out of sixty-five patients (17%) reported some balance symptoms after cisplatin therapy, including vertigo, dizziness, unsteadiness and falls. Vertigo was the most common balance symptom, reported by six patients (9.2%), and the clinical histories of these patients were consistent with benign paroxysmal positional vertigo (BPPV). Three patients (5%) had abnormal results of the CTSIB-m test, and they were the same patients that reported falls. Those who have noticeable hearing loss and peripheral neuropathy are more likely to have balance problems. Balance problems mainly affect quality of life of cancer survivors in the physical domain. Interview study: The themes included impact, coping strategies, experience through cancer journey, and opinions about investigation and management. Balance problems have an impact on physical and emotional aspects of life for cancer survivors with most participants rating low perceived handicap. These participants coped with balance symptoms using different strategies such as optimisation, lifestyle modification, or activity restriction. Positive attitudes along cancer journey have been described by most participants which demonstrate the ability of cancer survivors to turn around negative life experiences. Most participants did not say they needed help regarding balance problems. The concept of further investigation and management was generally acceptable but may not be needed for some individuals. Conclusion There is no definite vestibular dysfunction detected by video Head Impulse Test in cancer survivors who received cisplatin treatment. Vertigo triggered by BPPV is relatively prevalent in this group of patients and warrants further elucidation. Balance symptoms should not be overlooked and potentially affect one in six cancer survivors who received cisplatin. It is also important to identify the minority of cancer survivors who are significantly impacted with balance problems, and to offer appropriate physical and psychological support. Various research opportunities of both scientific and clinical value regarding the topic warrant more attention such as cancer survivor care and the better understanding of mechanisms of cisplatin ototoxicity

Vestibulotoxicity and balance problems associated with cisplatin chemotherapy in adult cancer survivors

Introduction and aims Cisplatin is an effective chemotherapeutic agent, but it has common side effects of ototoxicity and peripheral neuropathy which could potentially lead to balance problems. While cisplatin cochleotoxicity (causing hearing loss or tinnitus) is well documented, vestibulotoxicity (causing balance problems) is still unclear in literature. This thesis aimed to examine vestibular dysfunction and balance problems associated with cisplatin chemotherapy in adult cancer survivors to determine the epidemiology and impact of the problems. The project consists of 4 original research studies to evaluate the problems from patients and healthcare professional perspectives. Specific objectives of the studies were I. To examine current evidence and identify research gaps on vestibulotoxicity associated with cisplatin chemotherapy II. To explore knowledge, experiences, and opinions of audiovestibular professionals about cisplatin vestibulotoxicity III. To assess the vestibular function and balance problems in adult cancer survivors who had completed cisplatin chemotherapy treatment IV. To explore the lived experience and attitudes towards balance problems in adult cancer survivors who had completed cisplatin chemotherapy treatment Methods Scoping review: Research studies that mentioned vestibulotoxicity of cisplatin chemotherapy was identified through systematic literature search. Two researchers independently assessed and extracted data. Research findings were summarized narratively and research gaps were identified. Online survey: A questionnaire was developed to answer the specific research questions. Ninety-three clinicians working in the audiovestibular field participated in the online survey. Descriptive statistical analysis was conducted. Cross-sectional study: Sixty-five cancer survivors who had completed cisplatin treatment were recruited. The video Head Impulse Test (vHIT) of all semicircular canals was performed. Patient-reported balance symptoms were evaluated by a semi-structured clinical interview. Patients underwent bedside clinical tests including Dynamic Visual Acuity (DVA) test, Modified Clinical Testing of Sensory Interaction and Balance (CTSIB-m), and vibration sense testing to detect peripheral neuropathy. Descriptive and logistic regression statistical analyses were conducted. Interview study: Nine cancer survivors who had balance problems after chemotherapy treatment were interviewed. The interviews were transcribed, and analysed using inductive thematic analysis. Results Scoping review: Testing for cisplatin vestibulotoxicity predominately featured functional evaluation of the horizontal semicircular canal using the caloric and rotational tests. The rate of abnormal vestibular function test results after cisplatin treatment varied from 0 to 50%. The results of objective testing did not always correspond to patient symptoms. Online survey: Most of the audiovestibular professionals (87%) were aware of potential vestibulotoxicity associated with cisplatin chemotherapy, and some (31%) had seen patients with the condition. Forty percent of them were confident in making the diagnosis and in managing the patient in this situation. Cross-sectional study: All patients had normal vHIT results in all semicircular canals. Eleven out of sixty-five patients (17%) reported some balance symptoms after cisplatin therapy, including vertigo, dizziness, unsteadiness and falls. Vertigo was the most common balance symptom, reported by six patients (9.2%), and the clinical histories of these patients were consistent with benign paroxysmal positional vertigo (BPPV). Three patients (5%) had abnormal results of the CTSIB-m test, and they were the same patients that reported falls. Those who have noticeable hearing loss and peripheral neuropathy are more likely to have balance problems. Balance problems mainly affect quality of life of cancer survivors in the physical domain. Interview study: The themes included impact, coping strategies, experience through cancer journey, and opinions about investigation and management. Balance problems have an impact on physical and emotional aspects of life for cancer survivors with most participants rating low perceived handicap. These participants coped with balance symptoms using different strategies such as optimisation, lifestyle modification, or activity restriction. Positive attitudes along cancer journey have been described by most participants which demonstrate the ability of cancer survivors to turn around negative life experiences. Most participants did not say they needed help regarding balance problems. The concept of further investigation and management was generally acceptable but may not be needed for some individuals. Conclusion There is no definite vestibular dysfunction detected by video Head Impulse Test in cancer survivors who received cisplatin treatment. Vertigo triggered by BPPV is relatively prevalent in this group of patients and warrants further elucidation. Balance symptoms should not be overlooked and potentially affect one in six cancer survivors who received cisplatin. It is also important to identify the minority of cancer survivors who are significantly impacted with balance problems, and to offer appropriate physical and psychological support. Various research opportunities of both scientific and clinical value regarding the topic warrant more attention such as cancer survivor care and the better understanding of mechanisms of cisplatin ototoxicity