Role of L-type Ca2+ channels in transmitter release from mammalian inner hair cells. II. Single-neuron activity

Previously reported changes in the gross sound-evoked cochlear potentials after intracochlear perfusion of nimodipine suggest that dihydropyridine-sensitive Ca2+ channels (L-type) control the sound-evoked release of transmitter from the inner hair cells of the mammalian cochlea. In the present study, we combined recording of the action potentials of single primary auditory afferent neurons with intracochlear perfusion to further investigate the role of voltage-gated Ca2+ channels at this synapse. Spontaneous action potential firing rates were depressed by the L-type channel blocker nimodipine, but were elevated by S(-) BAY K8644, an L-type channel agonist. Sound-evoked responses of single primary afferents were depressed by nimodipine in a manner that was consistent with a block at the inner hair cell-afferent dendrite synapse. Perfusions with solutions containing the N-type channel blocker conotoxin GVIA did not differ in their effects from control artificial perilymph perfusions. The results extend the conclusions of the earlier study by showing that L-type Ca2+ channels are primarily responsible for controlling both spontaneous and sound-evoked transmitter release from inner hair cells. In addition it was found that afferent neurons with widely different spontaneous firing rates were all sensitive to nimodipine and to BAY K8644, suggesting that the multiple synaptic outputs of each inner hair cell are under the control of only one major type of Ca2+ channel.     

Bartter syndrome: an overview

The term Bartter syndrome denotes a group of renal diseases which share a common denominator of hypokalaemia and metabolic alkalosis. The patch-clamp technique has made possible the analysis of single ion channels, improving our understanding of the molecular physiopathology of all the 'Bartter-like' syndromes. Genetic mapping of each defect has further clarified the mutations involved and the possible modes of inheritance. This improved understanding has opened new avenues for therapy, improving mortality and morbidity in these patients. Another group of illnesses, the 'pseudo-Bartter syndrome', may produce a hypokalaemic metabolic alkalosis without primary renal disease. The underlying illness needs to be identified and treated.     

Levetiracetam for the treatment of hot flashes: a phase II study

Goals of work The objectives of this pilot trial were to assess the potential efficacy and safety of levetiracetam for the treatment of hot flashes, a major cause of morbidity among breast cancer survivors. Patients and methods Women, aged 18 years or more, with a history of breast cancer or those who wished to avoid estrogen because of a perceived increased risk of breast cancer, who were experiencing bothersome hot flashes (more than or equal to 14 times per week, for more than or equal to 1 month before study entry), were included. During the baseline week, general demographic characteristics, hot flash information, and quality of life data were obtained. At the beginning of week 2, patients were started on levetiracetam for a total of 4 weeks. Information about hot flashes, quality of life, and toxicity were collected during these 4 weeks and compared with the baseline week. Main results After treatment with levetiracetam for 4 weeks (N = 19), mean hot flash scores (frequency times mean severity) were reduced by 57%, and mean hot flash frequencies were reduced by 53%, compared to the baseline week; both these reductions were greater than what would be expected with a placebo (20–25% reduction). There were significant improvements in abnormal sweating (p = 0.004), hot flash distress (p = 0.0002), and satisfaction of hot flash control (p = 0.0001), when comparing data from the fourth week of treatment to the baseline week. Twenty-nine percent of the subjects did not complete the study because of treatment-related adverse events, with the most frequently reported side effects being somnolence, fatigue, and dizziness, usually with mild to moderate intensity. Conclusion The results of this pilot trial suggest that levetiracetam might be an effective therapy for the treatment of hot flashes. Further data are needed to test this hypothesis, evaluating the efficacy and toxicity of this agent. Financial Disclosure: None     

Temporal Trends in Inpatient Oncology Census Before and During the COVID-19 Pandemic and Rates of Nosocomial COVID-19 Among Patients with Cancer at a Large Academic Center

BackgroundThe coronavirus disease 2019 (COVID‐19) pandemic has significantly impacted health care systems. However, to date, the trend of hospitalizations in the oncology patient population has not been studied, and the frequency of nosocomial spread to patients with cancer is not well understood. The objectives of this study were to evaluate the impact of COVID‐19 on inpatient oncology census and determine the nosocomial rate of COVID‐19 in patients with cancer admitted at a large academic center.Materials and MethodsMedical records of patients with cancer diagnosed with COVID‐19 and admitted were reviewed to evaluate the temporal trends in inpatient oncology census during pre–COVID‐19 (January 2019 to February 2020), COVID‐19 (March to May 2020), and post–COVID‐19 surge (June to August 2020) in the region. In addition, nosocomial infection rates of SARS‐CoV‐2 were reviewed.ResultsOverall, the daily inpatient census was steady in 2019 (median, 103; range, 92–118) and until February 2020 (median, 112; range, 102–114). However, there was a major decline from March to May 2020 (median, 68; range, 57–104), with 45.4% lower admissions during April 2020. As the COVID‐19 surge eased, the daily inpatient census over time returned to the pre–COVID‐19 baseline (median, 103; range, 99–111). One patient (1/231, 0.004%) tested positive for SARS‐CoV‐2 13 days after hospitalization, and it is unclear if it was nosocomial or community spread.ConclusionIn this study, inpatient oncology admissions decreased substantially during the COVID‐19 surge but over time returned to the pre–COVID‐19 baseline. With aggressive infection control measures, the rates of nosocomial transmission were exceedingly low and should provide reassurance to those seeking medical care, including inpatient admissions when medically necessary.Implications for PracticeThe COVID‐19 pandemic has had a major impact on the health care system, and cancer patients are a vulnerable population. This study observes a significant decline in the daily inpatient oncology census from March to May 2020 compared with the same time frame in the previous year and examines the potential reasons for this decline. In addition, nosocomial rates of COVID‐19 were investigated, and rates were found to be very low. These findings suggest that aggressive infection control measures can mitigate the nosocomial infection risk among cancer patients and the inpatient setting is a safe environment, providing reassurance.