The use of spray electrocautery to control presacral bleeding: a report of four cases

Bleeding originating from the presacral venous plexus during pelvic operations is difficult to control, constituting a potentially life-threatening complication. Although suture ligatures, packing, and placement of tacks are established hemostatic techniques, they are often proved to be ineffective. We report a simple novel technique using spray diathermy for managing this severe complication. We have applied our method in four patients, two undergoing low anterior resection, and the others undergoing abdominoperineal resection for rectal cancer, that manifested severe presacral bleeding during rectal mobilization. Electrocautery at spray setting was applied slightly above the target bleeders at the presacral fascia, delivering a high-frequency electrical current in combination with drainage suction. In all cases, the method resulted in successful hemostasis. Applying spray electrocautery is a simple and effective method for controlling presacral bleeding. The advantages of using such a method instead of conventional hemostatic techniques include the option of varying the degree of haemostatic effect by altering the frequency and the volume of electric current.     

Chromatin structure and DNA methylation of the <Emphasis Type="Italic">IL-4 gene</Emphasis> in human T<Subscript>H</Subscript>2 cells

Human T_H2 cell differentiation results in the selective demethylation of several specific CpG dinucleotides in the IL-4 and IL-13 genes, which are expressed in activated T_H2, but not T_H1, cells. This demethylation is accompanied by the appearance of six DNase I hypersensitive sites within 1.4 kb at the 5'-end of the IL-4 gene. Micrococcal nuclease (MNase) digestion revealed that in both T_H1 and T_H2 cells nine nucleosomes with a repeat length of 201 bp are identically positioned around the 5'-end of the IL-4 gene. However, only in T_H2 cells are six out of the eight intervening linkers exposed to DNase I. This suggests that a major perturbation of the higher-order chromatin structure occurs above the level of the nucleosome in vivo. It is observed in cells that are poised for expression but which are not actively expressing the gene (i.e. resting T_H2 cells). Notably, all the demethylated CpGs in T_H2 cells are found in DNA that is accessible to DNase I. This may suggest that the opening of the chromatin structure allows binding of specific trans-acting factors that prevent de novo methylation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Nicole Winkelmann passed away in 2004.     

Homeostasis of Brain Dynamics in Epilepsy: A Feedback Control Systems Perspective of Seizures

In an effort to understand basic functional mechanisms that can produce epileptic seizures, some key features are introduced in coupled lumped-parameter neural population models that produce “seizure”-like events and dynamics similar to the ones during the route of the epileptic brain towards seizures. In these models, modified from existing ones in the literature, internal feedback mechanisms are incorporated to maintain the normal low level of synchronous behavior in the presence of coupling variations. While the internal feedback is developed using basic feedback systems principles, it is also functionally equivalent to actual neurophysiological mechanisms such as homeostasis that act to maintain normal activity in neural systems that are subject to extrinsic and intrinsic perturbations. Here it is hypothesized that a plausible cause of seizures is a pathology in the internal feedback action; normal internal feedback quickly regulates an abnormally high coupling between the neural populations, whereas pathological internal feedback can lead to “seizure”-like high amplitude oscillations. Several external seizure-control paradigms, that act to achieve the operational objective of maintaining normal levels of synchronous behavior, are also developed and tested in this paper. In particular, closed-loop “modulating” control with predefined stimuli, and closed-loop feedback decoupling control are considered. Among these, feedback decoupling control is the consistently successful and robust seizure-control strategy. The proposed model and remedies are consistent with a variety of recent observations in the human and animal epileptic brain, and with theories from nonlinear systems, adaptive systems, optimization, and neurophysiology. The results from the analysis of these models have two key implications, namely, developing a basic theory for epilepsy and other brain disorders, and the development of a robust seizure-control device through electrical stimulation and/or drug intervention modalities.

Normal and impaired reflexive orienting of attention after central nonpredictive cues

Recent studies suggest that stimuli with directional meaning can trigger lateral shifts of visuospatial attention when centrally presented as noninformative cues. We investigated covert orienting in healthy participants and in a group of 17 right brain-damaged patients (9 with hemispatial neglect) comparing arrows, eye gaze, and digits as central nonpredictive cues in a detection task. Orienting effects elicited by arrows and eye gaze were overall consistent in healthy participants and in right brain-damaged patients, whereas digit cues were ineffective. Moreover, patients with neglect showed, at the shortest delay between cue and target, a disengage deficit for arrow cueing whose magnitude was predicted by neglect severity. We conclude that the peculiar form of attentional orienting triggered by the directional meaning of arrow cues presents some features previously thought to characterize only the stimulus-driven (exogenous) orienting to noninformative peripheral cues.     

Lost in number space after right brain damage: a neural signature of representational neglect

The human brain represents numbers along a mental number line, whose spatial nature was confirmed by studies of patients with visuospatial neglect. Here we describe a neural signature of neglect for the left "number space" by using a task that does not require manipulation of numbers. Patients were asked to discriminate an infrequent ("one" or "nine") from a frequent spoken number word ("five"). P3b brain waves, elicited by infrequent stimuli and indexing cognitive processing, were delayed to targets on the left of the number line ("one") compared to targets on the right ("nine"). The delay of P3b is thus a neural signature of the disorder of representational space.     

Mefloquine-induced eosinophilic pneumonia

Mefloquine has been widely used for prophylaxis and treatment of patients with chloroquine-resistant malaria; the drug is usually well tolerated. Rarely, adverse effects may be severe, including gastrointestinal disturbances, neuropsychiatric reactions, cardiovascular manifestations, skin lesions, musculoskeletal symptoms, and bone marrow toxicity. We describe a 67-year-old woman with fever, dyspnea on exertion, peripheral blood eosinophilia, and diffuse pulmonary infiltrates on chest radiography. She had taken mefloquine for malaria prophylaxis for an 8-week trip to South Africa. A thorough work-up led to the diagnosis of eosinophilic pneumonia caused by the mefloquine. Her condition improved after the drug was discontinued. To our knowledge, this is the first report of mefloquine-induced eosinophilic pneumonia. Clinicians should be aware of this rare, potential adverse effect of mefloquine.     

Cardiac arrest and cardiopulmonary resuscitation in “hostile” environments: Using automated compression devices to minimize the rescuers’ danger

Mechanical automated compression devices are being used in cardiopulmonary resuscitation instead of manual, “hands-on”, rescuer-delivered chest compressions. The -theoretical- advantages include high-quality non-stop compressions, thus freeing the rescuer performing the compressions and additionally the ability of the rescuer to stand reasonably away from a potentially “hazardous” victim, or from hazardous and/or difficult resuscitation conditions. Such circumstances involve cardiopulmonary resuscitation (CPR) in the Cardiac Catheterization Laboratory, especially directly under the fluoroscopy panel, where radiation is well known to cause detrimental effects to the rescuer, and CPR during/after land or air transportation of cardiac arrest victims. Lastly, CPR in a coronavirus disease 2019 patient/ward, where the danger of contamination and further serious illness of the health provider is very existent. The scope of this review is to review and present literature and current guidelines regarding the use of mechanical compressions in these “hostile” and dangerous settings, while comparing them to manual compressions.