Effect of high-frequency oscillatory ventilation on the upper airways of kittens

BACKGROUND: High-frequency oscillatory ventilation (HFOV) has become the preferred method of ventilation for the fragile lungs of neonates and infants because its beneficial effects on lungs are well known; however, its benefits on upper airways are not yet known. We investigated the effects of HFOV and conventional mechanical ventilation (CMV) on the airways of kittens with normal lungs. METHODS: Ten healthy cross-bred kittens, 2-3-months-old, with a mean bodyweight of 0.98 kg, were randomly divided into two groups: HFOV and CMV. Kittens were intubated and ventilated for 24 h. A semiquantitative scoring system was used to grade histopathological tissue changes in the cricoid, mid-trachea, carina and left bonchus. The injury scores of the two groups were ranked and compared using a two-tailed Mann-Whitney rank test. RESULTS: Histopathologic changes were similar and mild in both groups under light microscopic examination. There was no significant difference in airway injury between the two groups. CONCLUSIONS: We conclude that, in this animal model, HFOV results in minimal airway damage when properly managed and causes no greater tracheobronchial injury than CMV.     

波峰因子在高频电刀工作模式检测中应用的研究

高频电刀在不同的工作模式下对应着不同特征的输出波形,通过对6个厂家的22个型号的上百台电刀进行实际检测,发现波峰因子是一个可以衡量电刀不同工作模式下输出信号特征的有效指标。本文分析了其中有代表性的部分检测结果,讨论了电刀的不同工作模式与波峰因子之间的关系,并提出可以将波峰因子作为高频电刀输出波形质量性能的检测指标。     

Effects of High-frequency Current on Pacemakers during Endoscopic Gastric Surgery: Experimental Study

Abstract: This study examined the effects of high-frequency current on pacemakers. Pacemakers were implanted in mongrel dogs, gastric mucosal resection was performed endoscopically using monopolar and bipolar snares, and the times for resection and magnitude of interference current (IC) in the myocardial electrodes were compared. The time for resection was 9.56±2.87 seconds with a monopolar snare and 0.82±0.13 seconds with a bipolar snare (p<0.01). The magnitude of the IC was 0.59±0.26 mV with a monopolar snare and 0.26±0.12 mV with a bipolar snare (p<0.01). The times required for resection and the magnitude of the IC using a bipolar snare in the coagulation mode at an output of approximately 12 W were 1.97±0.65 seconds and 0.03±0.02 mV, respectively, and those in the cutting mode were 1.68±0.50 seconds and 0.07±0.04 mV, respectively. The magnitude of the IC was significantly less (p<0.01), but the time required for resection was longer in the coagulation mode. No abnormalities were noted in the pacemaker mode in any of the 10 pacemakers examined after mucosal resection with high-frequency current at an output of 300 W. These results suggest that endoscopic therapy using high-frequency current can be performed more safely with a bipolar snare than with a monopolar snare in patients with pacemakers. In addition, the selection of the endoscope mode is considered to be important. (Dig Endosc 1999; 11: 150–157)     

Association of apolipoprotein E polymorphisms and dietary factors in colorectal cancer

ApoE single nucleotide polymorphisms (SNPs) Cys112Arg (Epsilon-4), and Arg158Cys (Epsilon-2) have been implicated in cardiovascular and Alzheimer''s disease, but their role in colorectal cancer (CRC) has not been extensively studied. We investigated whether ApoE polymorphisms alone or in combination with dietary factors selectively contribute to mismatch-repair (MMR) proficient (microsatellite stable/low or MSS/L) vs deficient (microsatellite unstable or MSI-H) CRCs. We carried out a case–control study with 906 CRC cases and 911 unaffected controls to examine the associations between ApoE polymorphisms and dietary factors and assessed their contribution to MSS/L and MSI-H CRCs. We used unconditional logistic regression to evaluate the associations between ApoE SNPs, tumour MSI status, and dietary factors after adjusting for age and sex. All statistical tests were two-sided. No significant differences in ApoE genotype frequencies were observed between CRC cases and unaffected controls. We observed that increased dietary intake of total fat, saturated fat, cholesterol, and red meat was significantly associated with CRC. Among non-ApoE4 carriers, 2–4 and >4 red meat servings/week were associated with developing MSS/L CRC (OR=1.51, 95% CI 1.10–2.07 and OR=1.80, 95% CI 1.30–2.48, respectively), whereas among ApoE4 allele carriers, four or more red meat servings/week were associated with MSI-H CRC (OR=4.62, 95% CI 1.20–17.77) when compared with the controls. ApoE isoforms modulate the risk of MSI-H and MSS/L CRCs among high red meat consumers.     

High-frequency jet ventilation using a helium–oxygen mixture

The physiological basis for the use of helium relates to the relationship described by Poiseuille. During turbulent gas flow, the factors determining the resistance to flow include the density of gas as well as the length and the radius of a tube. While it may not be possible to readily change the latter two, altering the density of the gas is possible by using helium instead of nitrogen. A helium-oxygen combination has been used most commonly to improve air exchange in patients with upper airway obstruction. Anecdotal reports also suggest the beneficial effects of helium during mechanical ventilation in patients with status asthmaticus, hyaline membrane disease, and other pulmonary parenchymal disorders. To date, the clinical reports have utilized helium only with conventional mechanical ventilation. We present a child whose progressive respiratory failure was treated by using high-frequency jet ventilation with a combination of helium and oxygen. The techniques for the delivery of helium and oxygen through the jet ventilator are discussed.     

Frequency-selectivity of a thalamocortical relay neuron during Parkinson's disease and deep brain stimulation: a computational study

In this computational study, we investigated (i) the functional importance of correlated basal ganglia (BG) activity associated with Parkinson's disease (PD) motor symptoms by analysing the effects of globus pallidus internum (GPi) bursting frequency and synchrony on a thalamocortical (TC) relay neuron, which received GABAergic projections from this nucleus; (ii) the effects of subthalamic nucleus (STN) deep brain stimulation (DBS) on the response of the TC relay neuron to synchronized GPi oscillations; and (iii) the functional basis of the inverse relationship that has been reported between DBS frequency and stimulus amplitude, required to alleviate PD motor symptoms [A. L. Benabid et al. (1991) Lancet , 337 , 403–406]. The TC relay neuron selectively responded to and relayed synchronized GPi inputs bursting at a frequency located in the range 2–25 Hz. Input selectivity of the TC relay neuron is dictated by low-threshold calcium current dynamics and passive membrane properties of the neuron. STN-DBS prevented the TC relay neuron from relaying synchronized GPi oscillations to cortex. Our model indicates that DBS alters BG output and input selectivity of the TC relay neuron, providing an explanation for the clinically observed inverse relationship between DBS frequency and stimulus amplitude.     

Intermittent subcutaneous apomorphine injection treatment for Parkinsonian motor oscillations

Eight patients with severe Parkinsonian motor oscillations have been treated with the dopamine receptor agonist apomorphine by intermittent subcutaneous self-injection as an adjunct to oral anti-Parkinsonian medication. The dopamine receptor antagonist domperidone was also given by mouth to prevent nausea. Six patients remain on chronic treatment (mean period 6.5 months) with improved control of motor function in each case. Four have had major enhancement of their quality of life. Benefits of this treatment stem from the training of patients to use intelligent behaviour to administer a promptly acting and effective pharmacological agent, thereby exercising a degree of direct control over previously unpredictable variations in motor performance.     

Pro/con clinical debate: High-frequency oscillatory ventilation is better than conventional ventilation for premature infants

Arguably one of the most important advances in critical care medicine in recent years has been the understanding that mechanical ventilators can impart harm and that lung-protective ventilation strategies can save lives. High-frequency oscillatory ventilation appears ideally suited for lung protection at first glance. Two camps of opinion exist, however, even in neonates where this modality has been most extensively studied. In the present debate, the prevailing arguments from each of those camps are made available for the reader to decide.     

Basal Ganglia dysfunctions in movement disorders: What can be learned from computational simulations

The basal ganglia are a complex neuronal system that is impaired in several movement disorders, including Parkinson's disease, Huntington's disease, and dystonia. Empirical studies have provided valuable insights into the brain dysfunctions underlying these disorders. The systems‐level perspective, however, of how patients' motor, cognitive, and emotional impairments originate from known brain dysfunctions has been a challenge to empirical investigations. These causal relations have been analyzed via computational modeling, a method that describes the simulation of interacting brain processes in a computer system. In this article, we review computational insights into the brain dysfunctions underlying Parkinson's disease, Huntington's disease, and dystonia, with particular foci on dysfunctions of the dopamine system, basal ganglia pathways, and neuronal oscillations. © 2016 International Parkinson and Movement Disorder Society