Exploratory Investigation of the Effects of Tactile Stimulation Using Air Pressure at the Auricular Vagus Nerve on Heart Rate Variability

OBJECTIVE

To explore the effects of tactile stimulation using air pressure at the auricular branch of the vagus nerve on autonomic activity in healthy individuals.

METHODS

Three types of tactile stimulation were used in this study: continuous low-amplitude, continuous high-amplitude, and pulsed airflow. The tactile stimulations were provided to the cymba concha to investigate autonomic activity in 22 healthy participants. The mean heart rate (HR) and parameters of HR variability, including the standard deviation of R-R intervals (SDNN) and root mean square of successive R-R interval differences (RMSSD) were compared at baseline, stimulation, and recovery periods.

RESULTS

Two-way repeated measures ANOVA indicated a significant main effect of time on HR (p=0.001), SDNN (p=0.003), and RMSSD (p<0.001). These parameters showed significant differences between baseline and stimulation periods and baseline and recovery periods in the post-hoc analyses. There were no significant differences in the changes induced by stimulation type and the interaction between time and stimulation type for all parameters. One-way repeated measures ANOVA showed that HR, SDNN, and RMSSD did not differ significantly among the three time periods during sham stimulation.

CONCLUSION

Parasympathetic activity can be enhanced by auricular tactile stimulation using air pressure, targeting the cymba concha. Further studies are warranted to investigate the optimal stimulation parameters for potential clinical significance.

In vivo gene editing via homology-independent targeted integration for adrenoleukodystrophy treatment

Adrenoleukodystrophy (ALD) is caused by various pathogenic mutations in the X-linked ABCD1 gene, which lead to metabolically abnormal accumulations of very long-chain fatty acids in many organs. However, curative treatment of ALD has not yet been achieved. To treat ALD, we applied two different gene-editing strategies, base editing and homology-independent targeted integration (HITI), in ALD patient-derived fibroblasts. Next, we performed in vivo HITI-mediated gene editing using AAV9 vectors delivered via intravenous administration in the ALD model mice. We found that the ABCD1 mRNA level was significantly increased in HITI-treated mice, and the plasma levels of C24:0-LysoPC (lysophosphatidylcholine) and C26:0-LysoPC, sensitive diagnostic markers for ALD, were significantly reduced. These results suggest that HITI-mediated mutant gene rescue could be a promising therapeutic strategy for human ALD treatment.

Reduced Interaction of Aggregated α-Synuclein and VAMP2 by Environmental Enrichment Alleviates Hyperactivity and Anxiety in a Model of Parkinson's Disease

Parkinson’s disease (PD) is a prevalent motor disease caused by the accumulation of mutated α-synuclein (α-Syn); however, its early stages are also characterized by non-motor symptoms, such as olfactory loss, cognitive decline, depression, and anxiety. The therapeutic effects of environmental enrichment (EE) on motor recovery have been reported, but its effects on non-motor symptoms remain unclear. Herein, we reveal the beneficial effects of EE on PD-related non-motor symptoms and changes in synaptic plasticity in the nucleus accumbens. To investigate its therapeutic effects in the early phase of PD, we randomly assigned eight-month-old mice overexpressing human A53T (hA53T) α-Syn to either the EE or standard condition groups for two months. Next, we performed behavioral tests and biochemical and histological analyses at 10 months of age. EE significantly alleviated locomotor hyperactivity and anxiety during the early stages of PD. It normalized the levels of tyrosine hydroxylase, phosphorylated and oligomeric α-Syn, and soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex-forming proteins, including synaptosomal-associated protein, 25 kDa, syntaxin1, and vesicle-associated membrane protein 2 (VAMP2). Moreover, the interactions between VAMP2 and pSer129 α-Syn were markedly reduced following EE. The restoration of synaptic vesicle transportation status may underlie the neuroprotective effects of EE in hA53T α-Syn mice.

Factors affecting cognition and emotion in patients with traumatic brain injury

BACKGROUND

Cognitive and emotional disturbances are common serious issues in patients with traumatic brain injury (TBI). However, predictors associated with neuropsychological functions were not consistent.

OBJECTIVE

To investigate factors affecting cognition and emotion in patients with TBI, we evaluated executive function, memory, and emotion based on injury severity and lesion location.

METHODS

Neuropsychological outcomes of 80 TBI patients were evaluated via Wisconsin Card Sorting Test (WCST), Color Trail Test (CTT), Controlled Oral Word Association Test (COWAT), Everyday Memory Questionnaire (EMQ), Geriatric Depression Scale (GDS), State-Trait Anxiety Inventory (STAI), and Agitated Behavior Scale (ABS). WCST, CTT, and COWAT assessed executive function; EMQ assessed everyday memory; and GDS, STAI, and ABS assessed emotion. Patients were categorized according to lateralization of lesion and existence of frontal lobe injury.

RESULTS

Patients with longer duration of loss of consciousness (LOC) showed more severe deficits in everyday memory and agitated behaviors. The frontal lesion group showed poorer performance in executive function and higher agitation than the non-frontal lesion group. Patients with bilateral frontal lesion showed greater deficits in executive function and were more depressed than unilateral frontal lesion groups. Especially in those unilateral frontal lesion groups, right side frontal lesion group was worse on executive function than left side frontal lesion group.

CONCLUSIONS

Duration of LOC and lesion location are main parameters affecting executive function, everyday memory, and emotion in neuropsychological outcomes following TBI, suggesting that these parameters need to be considered for cognitive rehabilitation interventions.

An Enriched Environment Ameliorates Oxidative Stress and Olfactory Dysfunction in Parkinson's Disease with α-Synucleinopathy

Parkinson’s disease (PD) features nonmotor symptoms such as olfactory dysfunction referred to as hyposmia, an initial sign of disease progression. Metabolic dysfunction can contribute to neurodegenerative diseases, and various xenobiotics and endogenous compounds are also involved in the pathogenesis of PD. Although aerobic exercise was found to induce preservation or improvement in olfactory function in PD patients in a recent study, the exact underlying mechanism for this effect is not clear. We aimed to investigate the influence of an enriched environment (EE) on olfactory dysfunction especially via metabolic pathways related to detoxification enzymes. Eight-month-old transgenic (Tg) PD mice that overexpress human A53T α-synuclein (α-syn) were randomly allocated to an EE or standard conditions for 2 mo. The buried food test showed that EE group had significantly improved olfactory function compared to the control group. Reverse transcription polymerase chain reaction (PCR) and real-time quantitative PCR showed that expression of the detoxification enzymes––cytochrome P450 family 1 subfamily A member 2, paraoxonase 1, alcohol dehydrogenase 1, UDP glucuronosyltransferase family 2 member A1 complex locus, aldehyde oxidase homolog 2, and aldehyde glutathione peroxidase 6––was significantly increased in the olfactory bulb (OB) of the PD control group, but these enzymes were normalized in the EE group. Immunohistochemical staining of the OB showed that oxidative stress and nitrated α-syn were significantly increased in the control group but decreased in the EE group. In conclusion, we suggest that exposure to an EE decreases both oxidative stress and nitrated α-syn, resulting in normalized detoxification enzymes and amelioration of olfactory dysfunction.

Neurobehavioral Assessments in a Mouse Model of Neonatal Hypoxic-ischemic Brain Injury

We performed unilateral carotid artery occlusion on CD-1 mice to create a neonatal hypoxic-ischemic (HI) model and investigated the effects of neonatal HI brain injury by studying neurobehavioral functions in these mice compared to non-operated (i.e., normal) mice. During the study, Rice-Vannucci's method was used to induce neonatal HI brain damage in postnatal day 7-10 (P7-10) mice. The HI operation was performed on the pups by unilateral carotid artery ligation and exposure to hypoxia (8% O2 and 92% N2 for 90 min). One week after the operation, the damaged brains were evaluated with the naked eye through the semi-transparent skull and were categorized into subgroups based on the absence ("no cortical injury" group) or presence ("cortical injury" group) of cortical injury, such as a lesion in the right hemisphere. On week 6, the following neurobehavioral tests were performed to evaluate the cognitive and motor functions: passive avoidance task (PAT), ladder walking test, and grip strength test. These behavioral tests are helpful in determining the effects of neonatal HI brain injury and are used in other mouse models of neurodegenerative diseases. In this study, neonatal HI brain injury mice showed motor deficits that corresponded to right hemisphere damage. The behavioral test results are relevant to the deficits observed in human neonatal HI patients, such as cerebral palsy or neonatal stroke patients. In this study, a mouse model of neonatal HI brain injury was established and showed different degrees of motor deficits and cognitive impairment compared to non-operated mice. This work provides basic information on the HI mouse model. MRI images demonstrate the different phenotypes, separated according to the severity of brain damage by motor and cognitive tests.

Heteronuclear recoupling in solid-state magic-angle-spinning NMR via overtone irradiation

A heteronuclear dipolar recoupling scheme applicable to I-S spin pairs undergoing magic-angle-spinning (MAS) is introduced, based on the overtone irradiation of one of the coupled nuclei. It is shown that when I is a quadrupole, for instance (14)N, irradiating this spin at a multiple of its Larmor frequency prevents the formation of MAS dipolar echoes. The ensuing S-spin signal dephasing is significant and dependent on a number of parameters, including the I-S dipolar coupling, the magnitude of I's quadrupolar coupling, and the relative orientations between these two coupling tensors. When applied to a spin-1 nucleus, this overtone recoupling method differs from hitherto proposed recoupling strategies in that it involves only the +/-1> I(z) eigenstates. Its dephasing efficiency becomes independent of first-order quadrupolar effects yet shows a high sensitivity to second-order offsets. A constant-time/variable-offset recoupling sequence thus provides a simple route to acquire, in an indirect fashion, (14)N overtone spectra from rotating powders. The principles underlying this kind of S-(14)N experiments and different applications involving S = (13)C, (59)Co sites are presented.

Maternal pre-eclampsia/eclampsia and the risk of sudden infant death syndrome in offspring

To determine whether maternal exposure to pre-eclampsia/eclampsia during pregnancy increases the risk of sudden infant death syndrome (SIDS) in offspring, we conducted a population-based case-control study using the California linked birth and death certificate data. All infants who died of SIDS (ICD-9 code 798.0) during 1989-91 were identified as cases. More than 96% of the identified SIDS cases were diagnosed through autopsy. Ten controls who did not die from SIDS were randomly selected for each case from the birth certificate matched to the case on the year of birth. Among 2,029 cases and 21,037 controls included in the final analysis, mothers of 49 cases (2.4%) and 406 controls (1.9%) had a diagnosis of either pre-eclampsia or eclampsia noted on the birth certificate. After adjustment for maternal age, prenatal smoking, race/ethnicity, parity, maternal education, gestational age at the initial visit for prenatal care, infant year of birth and infant sex, maternal pre-eclampsia/ eclampsia during pregnancy was associated with a 50% increased risk of SIDS in the offspring (odds ratio = 1.5, 95% confidence interval 1.1, 2.0). Potential under-reporting of pre-eclampsia/eclampsia on the birth certificates was likely to be non-differential and is unlikely to explain the finding. Fetal hypoxia resulting from pre-eclampsia/ eclampsia or immunological aetiology affecting the risk of both pre-eclampsia/eclampsia and SIDS may explain the finding.

Changing paternity and the risk of preeclampsia/eclampsia in the subsequent pregnancy

To determine whether changing paternity affects the risk of preeclampsia or eclampsia in the subsequent pregnancy and whether the effect depends on a woman's history of preeclampsia/eclampsia with her previous partner, a cohort study was conducted based on 140,147 women with two consecutive births during 1989-1991 identified through linking of annual California birth certificate data. Among women without preeclampsia/eclampsia in the first birth, changing partners resulted in a 30% increase in the risk of preeclampsia/eclampsia in the subsequent pregnancy compared with those who did not change partners (95% confidence interval: 1.1, 1.6). On the other hand, among women with preeclampsia/eclampsia in the first birth, changing partners resulted in a 30% reduction in the risk of preeclampsia/eclampsia in the subsequent pregnancy (95% confidence interval: 0.4, 1.2). The difference of the effect of changing paternity on the risk of preeclampsia/eclampsia between women with and those without a history of this condition was significant (p < 0.05 for the interaction term). The above estimates were adjusted for potential confounders. These findings suggest that the effect of changing paternity depends on the history of preeclampsia/eclampsia with the previous partner and support the hypothesis that parental human leukocyte antigen sharing may play a role in the etiology of preeclampsia/eclampsia.

Maternal placental abnormality and the risk of sudden infant death syndrome

To determine whether placental abnormality (placental abruption or placental previa) during pregnancy predisposes an infant to a high risk of sudden infant death syndrome (SIDS), the authors conducted a population-based case-control study using 1989-1991 California linked birth and death certificate data. They identified 2,107 SIDS cases, 96% of whom were diagnosed through autopsy. Ten controls were randomly selected for each case from the same linked birth-death certificate data, matched to the case on year of birth. About 1.4% of mothers of cases and 0.7% of mothers of controls had either placental abruption or placenta previa during the index pregnancy. After adjustment for potential confounders, placental abnormality during pregnancy was associated with a twofold increase in the risk of SIDS in offspring (odds ratio = 2.1, 95% confidence interval 1.3-3.1). The individual effects of placental abruption and placenta previa on the risk of SIDS did not differ significantly. An impaired fetal development due to placental abnormality may predispose an infant to a high risk of SIDS.

Transient neurologic symptoms after spinal anesthesia: an epidemiologic study of 1,863 patients

BACKGROUND

Recent evidence suggests that transient neurologic symptoms commonly follow lidocaine spinal anesthesia. However, information concerning factors that affect their occurrence is limited. Accordingly, to evaluate many potential risk factors, the authors undertook a prospective, multicenter, epidemiologic study.

METHODS

On a voluntary basis, anesthetists at 15 participating centers forwarded a data sheet on patients who had spinal anesthesia to a research nurse blinded to the details of anesthesia and surgery. A subset was randomly selected for follow-up. The pressure [corrected] of transient neurologic symptoms, defined as leg or buttock pain, was the principal outcome variable. Logistic regression was used to control for potential confounders, and adjusted odds ratios and confidence intervals were used to estimate relative risk.

RESULTS

During a 14-month period, 1,863 patients were studied, of whom 47% received lidocaine, 40% bupivacaine, and 13% tetracaine. Patients given lidocaine were at higher risk for symptoms compared with those receiving bupivacaine (relative risk, 5.1; 95% CI, 2.5 to 10.2) or tetracaine (relative risk, 3.2; 95% CI, 1.04 to 9.84). For patients who received lidocaine, the relative risk of transient neurologic symptoms was 2.6 (95% CI, 1.5 to 4.5) with the lithotomy position compared with other positions, 3.6 (95% CI, 1.9 to 6.8), for outpatients compared with inpatients, and 1.6 (95% CI, 1 to 2.5) for obese (body mass index >30) compared with nonobese patients.

CONCLUSIONS

These results indicate that transient neurologic symptoms commonly follow lidocaine spinal anesthesia but are relatively uncommon with bupivacaine or tetracaine. The data identify lithotomy position and outpatient status as important risk factors in patients who receive lidocaine. Among other factors postulated to increase risk, obesity had an effect of borderline statistical significance, whereas age, sex, history of back pain, needle type, and lidocaine dose and concentration failed to affect risk.

Predictions of protein secondary structures using factor analysis on Fourier transform infrared spectra: effect of Fourier self-deconvolution of the amide I and amide II bands

Fourier self-deconvolution (FSD) was performed on protein amide I and II Fourier transform infrared (FTIR) spectra to test if the resultant increased band shape variation would lead to improvements in protein secondary structure prediction with our factor analysis based restricted multiple regression (RMR) methods. FTIR spectra of 23 proteins dissolved in H2O were measured and normalized to a constant amide I peak absorbance. The deconvolved spectra were renormalized by area so that the deconvolved spectra sets had the same area as before. Principal component analysis of the deconvolved spectra sets was carried out, which was followed by a selective multiple linear regression (RMR) analysis of the principal component loadings with regard to the fractional components (FC) of secondary structure. As compared to analyses based on the original spectra set, helix and sheet predictions were not noticeably improved by FSD; but, if a very large number of component spectra (16) were retained in the pool to select which loadings to be used in the RMR optimization, better predictions of turn and "other" resulted. The prediction quality varied depending on the deconvolution parameters used.

Cystic fibrosis heterozygote screening in 5,161 pregnant women

A screening program for cystic fibrosis (CF) heterozygotes was conducted in a large HMO prenatal population, to evaluate the level of interest among eligible patients, the effectiveness of prescreening education, attitudes toward the screening process, psychological effects, and utilization of prenatal diagnosis and its outcomes. The heterozygote identification rate and frequency of specific CFTR mutations were also assessed. Identified carriers were offered genetic counseling and testing of male partners. Prenatal diagnosis was offered if both parents were identified as carriers. A total of 5,161 women underwent carrier testing; 947 others completed survey instruments only. The acceptance rate of screening was high (78%), and pretest education by videotape was generally effective. Adverse psychological effects were not reported. Participants generally found screening to be desirable and useful. Screening identified 142 female heterozygotes, 109 couples in which the male partner was not a carrier, and 7 high-risk couples. The incidence of R117H mutations was much higher than expected. The number of identified carriers was much lower in Hispanics than in Caucasians. We conclude that large-scale prenatal screening for CF heterozygotes in the absence of a family history of CF is an acceptable method for identifying couples at risk for affected fetuses. Sufficient pretest education can be accomplished efficiently, test insensitivity is well accepted, adverse psychological events are not observed, and general patient satisfaction is high.

Mortality following conjugal bereavement and the effects of a shared environment

The effect of bereavement on mortality among surviving spouses was examined in a cohort of 12,522 spouse pairs belonging to a prepaid health care plan in northern California. Both spouses were examined and completed a questionnaire between 1964 and 1973, and they were followed for mortality through 1987. Between 1964 and 1987, 1,453 men (12%) and 3,294 women (26%) were bereaved; 440 bereaved men (30%) and 510 women (15%) died during follow-up. Mortality following bereavement was significantly elevated in both men and women after adjusting for age, education, and other predictors of mortality in proportional hazards analyses. The highest relative risks (RRs) of mortality occurred 7-12 months following bereavement. Among women, the RR was 1.9 (95% confidence interval (CI) 1.35-2.71) 7-12 months after bereavement. Among men, the effect of bereavement interacted with prior health status as follows: In men with few health problems, the RR of mortality was 2.12 (95% CI 1.42-3.17); men with many health problems had a RR of 1.56 (95% CI 0.98-2.55) 7-12 months after bereavement. In both men and women, the RR declined after the first year of bereavement but remained above 1.0 for more than 2 years after bereavement. The addition of terms reflecting the influence of the other spouse's characteristics and behaviors did not alter the RR of mortality, indicating no effect of a shared unfavorable environment on mortality following bereavement.