A Randomized Crossover Study in Single-Sided Deafness Comparing a Cartilage Conduction CROS System and an Air-Conduction CROS System

OBJECTIVE

To investigate if cartilage conduction (CC) rerouting devices are noninferior to air-conduction (AC) rerouting devices for single-sided deafness (SSD) patients by measuring objective and subjective performance using speech-in-noise tests that resemble a realistic hearing environment, sound localization tests, and standardized questionnaires.

STUDY DESIGN

Prospective, single-subject randomized, crossover study.

SETTING

Anechoic room inside a university.

PATIENTS

Nine adults between 21 and 58 years of age with severe or profound unilateral sensorineural hearing loss.

INTERVENTIONS

Patients' baseline hearing was assessed; they then used both the cartilage conduction contralateral routing of signals device (CC-CROS) and an air-conduction CROS hearing aid (AC-CROS). Patients wore each device for 2 weeks in a randomly assigned order.

MAIN OUTCOME MEASURES

Three main outcome measures were 1) speech-in-noise tests, measuring speech reception thresholds; 2) proportion of correct sound localization responses; and 3) scores on the questionnaires, "Abbreviated Profile of Hearing Aid Benefit" (APHAB) and "Speech, Spatial, and Qualities of Hearing Scale" with 12 questions (SSQ-12).

RESULTS

Speech reception threshold improved significantly when noise was ambient, and speech was presented from the front or the poor-ear side with both CC-CROS and AC-CROS. When speech was delivered from the better-ear side, AC-CROS significantly improved performance, whereas CC-CROS had no significant effect. Both devices mainly worsened sound localization, whereas the APHAB and SSQ-12 scores showed benefits.

CONCLUSION

CC-CROS has noninferior hearing-in-noise performance except when the speech was presented to the better ear under ambient noise. Subjective measures showed that the patients realized the effectiveness of both devices.

Hearing and Hearing Loss Progression in Patients with GJB2 Gene Mutations: A Long-Term Follow-Up

We aimed to investigate whether the degree of hearing loss with GJB2 mutations could be predicted by distinguishing between truncating and non-truncating mutations and whether the genotype could predict the hearing loss level. Additionally, we examined the progression of hearing loss in individuals monitored for over 2 years for an average of 6.9 years. The proportion of truncating mutations was higher in patients with profound and severe hearing loss, but it was not accurate enough to predict the degree of hearing loss. Via genotype analysis, mutations of the p.Arg143Trp variants were associated with profound hearing loss, while mutations of the p.Leu79Cysfs*3 allele exhibited a wide range of hearing loss, suggesting that specific genotypes can predict the hearing loss level. Notably, there were only three cases of progression in four ears, all of which involved the p.Leu79Cysfs*3 mutation. Over the long-term follow-up, 4000 Hz was significant, and there was a trend of progression at 250 Hz, suggesting that close monitoring at these frequencies during follow-up may be crucial to confirm progression. The progression of hearing loss was observed in moderate or severe hearing loss cases at the time of the initial diagnosis, emphasizing that children with this level of hearing loss need regular follow-ups.

Predicting synkinesis caused by Bell's palsy or Ramsay Hunt syndrome using machine learning-based logistic regression

Objective

To investigate whether machine learning (ML)-based algorithms, namely logistic regression (LR), random forest (RF), k-nearest neighbor (k-NN), and gradient-boosting decision tree (GBDT), utilizing early post-onset parameters can predict facial synkinesis resulting from Bell's palsy or Ramsay Hunt syndrome more accurately than the conventional statistics-based LR.

Methods

This retrospective study included 362 patients who presented to a facial palsy outpatient clinic. Median follow-up of synkinesis-positive and -negative patients was 388 (range, 177-1922) and 198 (range, 190-3021) days, respectively. Electrophysiological examinations were performed, and the rate of synkinesis in Bell's palsy and Ramsay Hunt syndrome was evaluated. Sensitivity and specificity were assessed using statistics-based LR; and electroneurography (ENoG) value, the difference in the nerve excitability test (NET), and scores of the subjective Yanagihara scaling system were evaluated using early post-onset parameters with ML-based LR, RF, k-NN, and GBDT.

Results

Synkinesis rate in Bell's palsy and Ramsay Hunt syndrome was 20.2% (53/262) and 40.0% (40/100), respectively. Sensitivity and specificity obtained with statistics-based LR were 0.796 and 0.806, respectively, and the area under the receiver operating characteristic curve (AUC) was 0.87. AUCs measured using ML-based LR of "ENoG," "difference in NET," "Yanagihara," and all three components ("all") were 0.910, 0.834, 0.711, and 0.901, respectively.

Conclusion

ML-based LR model shows potential in predicting facial synkinesis probability resulting from Bell's palsy or Ramsay Hunt syndrome and has comparable reliability to the conventional statistics-based LR.

Level of Evidence

3.

Three-dimensional mouse cochlea imaging based on the modified Sca/eS using confocal microscopy

The three-dimensional stria vascularis (SV) and cochlear blood vessel structure is essential for inner ear function. Here, modified Sca/eS, a sorbitol-based optical-clearing method, was reported to visualize SV and vascular structure in the intact mouse cochlea. Cochlear macrophages as well as perivascular-resident macrophage-like melanocytes were detected as GFP-positive cells of the CX3CR1^+/GFP mice. This study's method was effective in elucidating inner ear function under both physiological and pathological conditions.

Unbiased approach to identify and assess efficacy of human SARS-CoV-2 neutralizing antibodies

Coronavirus disease 2019 (COVID-19) continues to significantly impact the global population, thus countermeasure platforms that enable rapid development of therapeutics against variants of SARS-CoV-2 are essential. We report use of a phage display human antibody library approach to rapidly identify neutralizing antibodies (nAbs) against SARS-CoV-2. We demonstrate the binding and neutralization capability of two nAbs, STI-2020 and STI-5041, against the SARS-CoV-2 WA-1 strain as well as the Alpha and Beta variants. STI-2020 and STI-5041 were protective when administered intravenously or intranasally in the golden (Syrian) hamster model of COVID-19 challenged with the WA-1 strain or Beta variant. The ability to administer nAbs intravenously and intranasally may have important therapeutic implications and Phase 1 healthy subjects clinical trials are ongoing.

Role of Oxidative Stress and Antioxidants in Acquired Inner Ear Disorders

Oxygen metabolism in the mitochondria is essential for biological activity, and reactive oxygen species (ROS) are produced simultaneously in the cell. Once an imbalance between ROS production and degradation (oxidative stress) occurs, cells are damaged. Sensory organs, especially those for hearing, are constantly exposed during daily life. Therefore, almost all mammalian species are liable to hearing loss depending on their environment. In the auditory pathway, hair cells, spiral ganglion cells, and the stria vascularis, where mitochondria are abundant, are the main targets of ROS. Excessive generation of ROS in auditory sensory organs is widely known to cause sensorineural hearing loss, and mitochondria-targeted antioxidants are candidates for treatment. This review focuses on the relationship between acquired hearing loss and antioxidant use to provide an overview of novel antioxidants, namely medicines, supplemental nutrients, and natural foods, based on clinical, animal, and cultured-cell studies.

In vivo Chronic Two-Photon Imaging of Microglia in the Mouse Hippocampus

Microglia, the only immune cells resident in the brain, actively participate in neural circuit maintenance by modifying synapses and neuronal excitability. Recent studies have revealed the differential gene expression and functional heterogeneity of microglia in different brain regions. The unique functions of the hippocampal neural network in learning and memory may be associated with the active roles of microglia in synapse remodeling. However, inflammatory responses induced by surgical procedures have been problematic in the two-photon microscopic analysis of hippocampal microglia. Here, a method is presented that enables the chronic observation of microglia in all layers of the hippocampal CA1 through an imaging window. This method allows the analysis of morphological changes in microglial processes for more than 1 month. Long-term and high-resolution imaging of the resting microglia requires minimally invasive surgical procedures, appropriate objective lens selection, and optimized imaging techniques. The transient inflammatory response of hippocampal microglia may prevent imaging immediately after surgery, but the microglia restore their quiescent morphology within a few weeks. Furthermore, imaging neurons simultaneously with microglia allows us to analyze the interactions of multiple cell types in the hippocampus. This technique may provide essential information about microglial function in the hippocampus.

CD4 T-cell depletion prevents Lassa fever associated hearing loss in the mouse model

Lassa virus (LASV) is the causative agent of Lassa fever (LF), which presents as a lethal hemorrhagic disease in severe cases. LASV-induced hearing loss in survivors is a huge socioeconomic burden, however, the mechanism(s) leading to hearing loss is unknown. In this study, we evaluate in a mouse LF model the auditory function using auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE) to determine the mechanisms underlying LASV-induced hearing loss. In the process, we pioneered measures of ABR and DPOAE tests in rodents in biosafety level 4 (BSL-4) facilities. Our T cell depletion studies demonstrated that CD4 T-cells play an important role in LASV-induced hearing loss, while CD8 T-cells are critical for the pathogenicity in the acute phase of LASV infection. Results presented in this study may help to develop future countermeasures against acute disease and LASV-induced hearing loss.

Prolonged and extended impacts of SARS-CoV-2 on the olfactory neurocircuit

The impact of SARS-CoV-2 on the olfactory pathway was studied over several time points using Syrian golden hamsters. We found an incomplete recovery of the olfactory sensory neurons, prolonged activation of glial cells in the olfactory bulb, and a decrease in the density of dendritic spines within the hippocampus. These data may be useful for elucidating the mechanism underlying long-lasting olfactory dysfunction and cognitive impairment as a post-acute COVID-19 syndrome.

Regeneration Profiles of Olfactory Epithelium after SARS-CoV-2 Infection in Golden Syrian Hamsters

Olfactory dysfunction is one of the most frequent and specific symptoms of coronavirus disease 2019 (COVID-19). Information on the damage and repair of the neuroepithelium and its impact on olfactory function after COVID-19 is still incomplete. While severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes the ongoing worldwide outbreak of COVID-19, little is known about the changes triggered by SARS-CoV-2 in the olfactory epithelium (OE) at the cellular level. Here, we report profiles of the OE after SARS-CoV-2 infection in golden Syrian hamsters, which is a reliable animal model of COVID-19. We observed severe damage in the OE as early as 3 days postinoculation and regionally specific damage and regeneration of the OE within the nasal cavity; the nasal septal region demonstrated the fastest recovery compared to other regions in the nasal turbinates. These findings suggest that anosmia related to SARS-CoV-2 infection may be fully reversible.

A Novel Technique for Imaging and Analysis of Hair Cells in the Organ of Corti Using Modified Sca/eS and Machine Learning

Here, we describe a sorbitol-based optical clearing method, called modified Sca/eS that can be used to image all hair cells (HCs) in the mouse cochlea. This modification of Sca/eS is defined by three steps: decalcification, de-lipidation, and refractive index matching, which can all be completed within 72 h. Furthermore, we established automated analysis programs that perform machine learning-based pattern recognition. These programs generate 1) a linearized image of HCs, 2) the coordinates of HCs, 3) a holocochleogram, and 4) clusters of HC loss. In summary, a novel approach that integrates modified Sca/eS and programs based on machine learning facilitates quantitative and comprehensive analysis of the physiological and pathological properties of all HCs.

LAMP5 in presynaptic inhibitory terminals in the hindbrain and spinal cord: a role in startle response and auditory processing

Lysosome-associated membrane protein 5 (LAMP5) is a mammalian ortholog of the Caenorhabditis elegans protein, UNC-46, which functions as a sorting factor to localize the vesicular GABA transporter UNC-47 to synaptic vesicles. In the mouse forebrain, LAMP5 is expressed in a subpopulation of GABAergic neurons in the olfactory bulb and the striato-nigral system, where it is required for fine-tuning of GABAergic synaptic transmission. Here we focus on the prominent expression of LAMP5 in the brainstem and spinal cord and suggest a role for LAMP5 in these brain regions. LAMP5 was highly expressed in several brainstem nuclei involved with auditory processing including the cochlear nuclei, the superior olivary complex, nuclei of the lateral lemniscus and grey matter in the spinal cord. It was localized exclusively in inhibitory synaptic terminals, as has been reported in the forebrain. In the absence of LAMP5, localization of the vesicular inhibitory amino acid transporter (VIAAT) was unaltered in the lateral superior olive and the ventral cochlear nuclei, arguing against a conserved role for LAMP5 in trafficking VIAAT. Lamp5 knockout mice showed no overt behavioral abnormality but an increased startle response to auditory and tactile stimuli. In addition, LAMP5 deficiency led to a larger intensity-dependent increase of wave I, II and V peak amplitude of auditory brainstem response. Our results indicate that LAMP5 plays a pivotal role in sensorimotor processing in the brainstem and spinal cord.

Cellular cartography of the organ of Corti based on optical tissue clearing and machine learning

The highly organized spatial arrangement of sensory hair cells in the organ of Corti is essential for inner ear function. Here, we report a new analytical pipeline, based on optical clearing of tissue, for the construction of a single-cell resolution map of the organ of Corti. A sorbitol-based optical clearing method enabled imaging of the entire cochlea at subcellular resolution. High-fidelity detection and analysis of all hair cell positions along the entire longitudinal axis of the organ of Corti were performed automatically by machine learning–based pattern recognition. Application of this method to samples from young, adult, and noise-exposed mice extracted essential information regarding cellular pathology, including longitudinal and radial spatial characteristics of cell loss, implying that multiple mechanisms underlie clustered cell loss. Our method of cellular mapping is effective for system-level phenotyping of the organ of Corti under both physiological and pathological conditions.

Scaphoid nonunion with carpal ligament injury - radiological, arthroscopical assessment and clinical results

The purpose of this study was to review the clinical results of carpal ligaments injuries with scaphoid nonunion. We hypothesized that scaphoid nonunion with carpal ligament injury is associated with clinical result. We retrospectively reviewed 60 cases of -Herbert screw fixation with bone graft for scaphoid nonunions. Scapholunate (SL) and lunotriquetral (LT) ligaments lesions were confirmed by arthroscopy. Approximately half of the nonunion scaphoid cases had carpal ligaments injuries. At final follow-up evaluation, wrist function as evaluated by the Mayo wrist score was excellent in 34 patients, good in 16 patients, fair in 8 patients, and poor in 2 patients. Cases with both SL/LT ligaments injuries tended to have decreased wrist flexion-extension motion. Our results suggest that there is an indication for arthroscopy in scaphoid nonunion if surgical fixation is offered to avoid detrimental effects of an undiagnosed ligament tear.

Effects of depression and inflammatory factors on chronic conditions of the wrist

Aims

Chronic conditions of the wrist may be difficult to manage because pain and psychiatric conditions are correlated with abnormal function of the hand. Additionally, intra-articular inflammatory cytokines may cause pain. We aimed to validate the measurement of inflammatory cytokines in these conditions and identify features associated with symptoms.

Patients and Methods

The study included 38 patients (18 men, 20 women, mean age 43 years) with a chronic condition of the wrist who underwent arthroscopy. Before surgery, the Self-Rating Depression Scale (SDS), Hand20 questionnaire and a visual analogue scale (VAS) for pain were used. Cytokine and chemokine levels in the synovial fluid of the wrist were measured using enzyme-linked immunosorbent assays and correlations between the levels with pain were analysed. Gene expression profiles of the synovial membranes were assessed using quantitative polymerase chain reaction.

Results

Older patients had high pre-operative Hand20 scores. One-year post-operative Hand20 and VAS scores and pre-operative VAS scores correlated with SDS scores. Post-operative VAS scores negatively correlated with the expression of nerve growth factor and SDS scores positively correlated with the expression of tumour necrosis factor-alpha and negatively correlated with the expression of tumour necrosis factor-converting enzyme.

Conclusion

There was a positive correlation between depression and chronic conditions of the wrist. Levels of some cytokines correlate with pain and depression. Additionally, cytokines may be important in the assessment and treatment of chronic conditions of the wrist and depression. Cite this article: Bone Joint J 2016;98-B:961–8.

Potentially lethal pharyngolaryngeal edema with dyspnea in adult patients with mumps: A series of 5 cases

In this article we describe 5 rare cases of mumps-associated pharyngolaryngeal edema. To the best of our knowledge, this report includes the first case of mumps-associated pharyngolaryngeal edema in a patient who had previously received mumps vaccination, and these cases represent the sixth report of mumps-associated pharyngolaryngeal edema in the English literature. All 5 of our patients with mumps infection were adults and manifested airway stenosis due to pharyngolaryngeal edema. This edema responded favorably to steroid treatment without tracheotomy. We conclude that a pharyngolaryngeal examination is recommended for patients with mumps infection. Steroid treatment is usually effective against pharyngolaryngeal edema; however, in certain cases tracheotomy may be inevitable.

Expression of IL-33 and its receptor ST2 in chronic rhinosinusitis with nasal polyps

OBJECTIVES/HYPOTHESIS

Interleukin (IL)-33 is a novel member of the IL-1 cytokine family and a ligand for the orphan IL-1 family receptor ST2. IL-33 induces T helper 2-type inflammatory responses and is considered to play a crucial role in allergic inflammatory reactions such as asthma and atopic dermatitis. However, the role of IL-33 and its receptor ST2 in chronic rhinosinusitis remains unclear.

STUDY DESIGN

In vitro study.

METHODS

The expression patterns of IL-33 and ST2 at both mRNA and protein levels in nasal polyps from eosinophilic chronic rhinosinusitis (ECRS) patients (n = 10) and non-ECRS patients (n = 13), as well as in seemingly normal mucosa of the uncinate processes in patients without sinusitis (control; n = 5), were compared using immunohistochemical staining, enzyme-linked immunosorbent assay, and real-time polymerase chain reactions.

RESULTS

ST2-positive cells in the inflammatory cells in the subepithelial layer were significantly higher in the ECRS group than other groups. The expression of ST2 mRNA in polyps of the ECRS group was significantly increased compared with controls. Many ST2-positive eosinophils were observed in the mucosa of ECRS but not in the mucosa of non-ECRS patients. The expression level of IL-33 mRNA was not significantly different among the three groups.

CONCLUSIONS

The current study suggests that IL-33 and its receptor ST2 may play important roles in the pathogenesis of chronic rhinosinusitis, especially in ECRS, through the increased expression of ST2 in eosinophils.

LEVEL OF EVIDENCE

N/A.

Surgical management of a giant cervical ganglioneuroma

An 18-year-old patient presented with a major complaint of a mass in the right side of the neck. At the previous clinic, the patient underwent an open biopsy because the mass could not be diagnosed by fine needle aspiration. The patient was introduced to our institution after mass was diagnosed as ganglioneuroma by open biopsy. In our outpatient clinic, magnetic resonance imaging (MRI) and computed tomography (CT) were performed. Gradual growth of the mass was accompanied by sleep apnea syndrome. Ultimately, the patient was only able to sleep with nasal continuous positive airway pressure. Pathological examination confirmed the ganglioneuroma. MRI revealed expansion of the ganglioneuroma from the nasopharynx to the right upper mediastinum, occupying the surroundings of the contralateral carotid artery via the retropharyngeal space. CT revealed a tumor mass of 160mm×60mm×190mm in size. The mass was surgically resected without any postoperative neurological disorder including Horner syndrome. The clinical course was successful without recurrence. This is the first report of a successful treatment of a large ganglineuroma that had continuously expanded to the contralateral neck via the retropharyngeal space.

Thermoelectric properties of Ni-based oxides

A high-throughput screening technique has been developed and was utilized in the discovery of a new n-type oxide possessing good thermoelectric properties. Screening of metal binary systems consisting of 3d transition metals using this technique showed LaNiO3 to possess the desired n-type properties. Electrical resistivity (ρ) of this oxide is favorably quite low, however, the Seebeck coefficient (S) is as small as –25 μV/K. To enhance the thermoelectric properties of LaNiO3, high-throughput screening was employed to examine candidates from the metal ternary La1–xMxNiO3 and LaNi1–xNxO3 systems. Bi substitution in the La1–xMxNiO3 systems and Cu substitution in the LaNi1–xNxO3 systems were found to be effective for improvement of S and ρ respectively.

From amino acid landscape to protein landscape: analysis of genetic codes in terms of fitness landscape

Assigning the values of a certain physicochemical property for individual amino acids to the corresponding codons, we can make an amino acid property "landscape" on a four valued three dimensional sequence space from a genetic code table. Eleven property landscapes made from the standard genetic code (SGC) were analyzed. The evaluation of correlation for each landscape is done by theta value, which represents the ratio of the mean slope (as an additive term) to the degree of roughness (as a nonadditive term). The theta-values for hydropathy indices, polarity, specific heat, and beta-sheet propensity were considerably large with respect to SGC. This implies that the additivity of the contribution from each letter holds for these properties. To clarify the meaning of the so-called mutational robustness of SGC, we next examined correlations between the amino acid property and the actual "site fitnesses" of a protein. The site fitnesses were derived from a set of binding preference scores of amino acid residues at every site in MHC class I molecule binding peptides (Udaka et al. in press). We found that the SGC's theta value for an amino acid property is correlated with the significance of the property in the protein function. Adaptive walk simulation on fitness (= affinity) landscapes in a base sequence space for these model peptides confirmed better evolvability due to the introduction of SGC.

Transient decrease in skin resistance response and level at the deh-chi stage caused by manual acupuncture

Deh-chi is described as a kind of soreness, numbness, or heavy swelling in deep tissues during manual acupuncture. This finding is important in acupuncture therapy, although the mechanism of this phenomenon remains unclear. Skin resistance response (SRR) and skin resistance level (SRL) are expressed as a component of alternating current and direct current changes in electrodermal activity (EDA) respectively. In the present study, we recorded SRR and SRL, skin blood flow and perspiration simultaneously in an attempt to determine the relationship between skin sympathetic nerve activity and EDA at the deh-chi stage. We found that SRR, SRL and skin blood flow decrease, and that perspiration increases transiently at the deh-chi stage. Our findings indicate that manual acupuncture causes an increase in vasomotor and sudomotor activities, a decrease in skin blood flow, and increased perspiration. These SRR and SRL recordings may be taken as an indicator of deh-chi.

[A case of neonatal herpes simplex virus encephalitis with calcifications of thalamus and basal ganglia]

A male infant developed left-sided myoclonus associated with low grade fever at 21 days of age. The course of pregnancy and delivery had been uneventful. Birth weight was 2,240g at 38 weeks of gestation. Physical examination at 26 days of age revealed hyperirritability and incomplete Moro reflex. EEG showed periodic discharges originating in the right central region. Initial brain CT at 26 days of age showed no apparent abnormality. In lumbar CSF protein was 173 mg/dl, and nucleated cells 328/mm3 (polynuclear cells 6 and mononuclear cells 322). Cultures of CSF for bacteria and viruses were negative. Although, the serum titers of CF antibody to herpes simplex virus (HSV) were 1:4 to 1:8 during hospitalization and those in CSF were not increased significantly, ELISA titers for IgG and IgM in serum and CSF rose significantly. The diagnosis of HSV encephalitis was made at 41 days of age. His myoclonus was well controlled with phenobarbital and clonazepam. He was treated with acyclovir and CSF findings returned to normal. On 2nd brain CT (39 days of age), calcification at thalamus, basal ganglia and right frontal lobe, which is extremely rare CT findings for HSV encephalitis, was noticed. His DQ at discharge was about 90. It is emphasized that the early diagnosis of HSV encephalitis can be made by ELISA and serial brain CT examinations, and that HSV encephalitis should be considered when calcification of thalamus and basal ganglia are detected on brain CT.

Effect of deuterium oxide (D2O) on the IgE-mediated Ca2+ influx, arachidonic acid and histamine release in rat basophilic leukemia cells

Deuterium oxide (D2O), which is known to stimulate microtubule aggregation, enhanced the IgE-mediated 45Ca2+ influx, (14C)-arachidonic acid and histamine release in rat basophilic leukemia cells (RBL-2H3) in the same dose-dependent manner (up to 90% (v/v]. We compared the interaction between D2O and a variety of groups of pharmacological agents. A microtubule depolymerizing agent, demecolcine, which inhibited the IgE-mediated (14C)-arachidonic acid and histamine release without affecting 45Ca2+ influx, was counteracted by 45% D2O. Taxol, a microtubule stabilizing agent, which had an inhibitory effect on the above three steps, was also reversed by 45% D2O. These results would support the previous data on the interaction between D2O and microtubules and would further suggest that the status of microtubule aggregation may be related to the secretory process. Calmodulin inhibitors (W-7, trifluoperazine) blocked the IgE-mediated 45Ca2+ influx, (14C)-arachidonic acid and histamine release in the same dose-dependent manner, but were counteracted by 45% D2O. In contrast, the effects of proteinase inhibitors (TPCK, TLCK), an adenylate cyclase inhibitor (ddAdo), a phosphodiesterase inhibitor (aminophylline), a phospholipid methylation inhibitor (DZA + Hcy) and microfilament blockers (cytochalasin B and D) were not counteracted by 45% D2O. These results would suggest that D2O may be associated with calmodulin directly or indirectly possibly through some relationship between calmodulin and microtubules.