Does electromagnetic interference not occur to a bipolar pacemaker during TUR-P?

It has been reported that a unipolar pacemaker is more sensitive to electromagnetic interference (EMI) than a bipolar pacemaker. However, we experienced cases in which electrosurgery device interfered with a bipolar pacemaker, but not with a unipolar pacemaker during TUR-P. It has been suggested that EMI occurs to a bipolar pacemaker depending on sensitivity and electric resistance of a patient.     

Endoscopic features of impacted ureteral stones

PURPOSE: We retrospectively evaluated endoscopic findings in 165 patients with impacted ureteral stones to determine the incidence of associated ureteral lesions and predisposing factors for such lesions. MATERIALS AND METHODS: From July 1993 to March 2003 we performed retrograde endoscopic treatment in 165 patients with ureteral stones that had been impacted for more than 2 months. Average maximum stone diameter was 15.0 mm and the mean duration of impaction was 17.6 months. Treatment was done with small caliber ureteroscopes and a laser lithotriptor. We analyzed the endoscopic findings and determined the outcome by reviewing the clinical records and radiographic studies. RESULTS: Endoscopic observation revealed inflammatory ureteral polyps associated with calculi in 51 patients (30.9%). Endoscopic biopsy of 5 polyps was performed. Histological examination showed no malignancy and only chronic granulomatous inflammation of the ureter. Endoscopic observation also detected ureteral stricture in 28 patients (17.0%). Patients with polyps and strictures had long-term impaction (median 12 and 24 months, respectively), which was significantly longer than in patients without ureteral lesions (4 months). CONCLUSIONS: Endoscopic observation revealed that long-term impacted stones were frequently associated with ureteral polyps and strictures. Although concurrent ureteral lesions can make it more difficult to approach the calculus in patients with impacted stones, we found that a small caliber flexible endoscope was effective and laser fragmentation could be achieved easily.     

Recalibration of audiovisual simultaneity

To perceive the auditory and visual aspects of a physical event as occurring simultaneously, the brain must adjust for differences between the two modalities in both physical transmission time and sensory processing time. One possible strategy to overcome this difficulty is to adaptively recalibrate the simultaneity point from daily experience of audiovisual events. Here we report that after exposure to a fixed audiovisual time lag for several minutes, human participants showed shifts in their subjective simultaneity responses toward that particular lag. This 'lag adaptation' also altered the temporal tuning of an auditory-induced visual illusion, suggesting that adaptation occurred via changes in sensory processing, rather than as a result of a cognitive shift while making task responses. Our findings suggest that the brain attempts to adjust subjective simultaneity across different modalities by detecting and reducing time lags between inputs that likely arise from the same physical events.     

Proper arrangement of the lines and cables in the setup of the laparoscopic surgery: development of new device "Line-Hanger"

Recently, with the rapid progress and introduction of new machineries and instruments for endoscopic surgery, the connecting lines and cables connecting machineries around the operating field are becoming more and more complicated. The lines and cables are often very troublesome, especially when the operator and assistant change their positions, and sometimes they are not only annoying but also potentially dangerous during the operative procedure. We feel there is a pressing need to develop a device to regulate the lines and cables. We developed a device for regulating the lines and cables in cooperation with Olympus Optical Co, Ltd (Tokyo, Japan) and named it "Line-Hanger." We have used it in more than 30 cases of various kinds of endoscopic surgery. In this study, we compare the usefulness of the "Line-Hanger" with the conventional method: fixation of lines and cables to the drapes with Velcro(R). The girth of the operative personnel are freed from a jumble of cables, and they become ergonomically comfortable. Especially when operator and assistant are changing their position, it becomes very smooth. "Line-Hanger" is extremely useful for endoscopic surgery.     

Pulmonary hamartoma: unusual radiologic appearance

A pulmonary nodule was incidentally detected in a 50-year-old man during a routine health evaluation. High-resolution computed tomography (HRCT) showed that the lesion had the appearance of a collection of multiple tiny nodules. Histologic examination of the resected specimen revealed a single hamartoma resembling a bunch of grapes. Pulmonary alveoli and bronchioles were entrapped within the hamartoma with tumor buds appearing in a multicentric manner, thereby producing the unusual HRCT findings. Review of chest radiographs taken over the previous 20 years indicated that the tumor doubling time was 4968 days.     

Beta2-glycoprotein I, anti-beta2-glycoprotein I, and fibrinolysis

β₂-glycoprotein-I (β₂GPI) is a phospholipid-binding plasma protein that consists of five homologous domains. Domain V is distinguished from others by bearing a positively charged lysine cluster and hydrophobic extra C-terminal loop. β₂GPI has been known as a natural anticoagulant regulator. β₂GPI exerts anticoagulant activity by inhibition of phospholipid-dependent coagulation reactions such as prothrombinase, tenase, and factor XII activation. It also binds factor XI and inhibits its activation. On the other hand, β₂GPI inhibits anticoagulant activity of activated protein C. According to the data from knockout mice, β₂GPI may contribute to thrombin generation in vivo. Phospholipid-bound β₂GPI is one of the major target antigens for antiphospholipid antibodies present in patients with antiphospholipid syndrome (APS). Binding of pathogenic anti-β₂GPI antibodies increases the affinity of β₂GPI to the cell surface and disrupts the coagulation/fibrinolysis balance on the cell surface. These pathogenic antibodies activate endothelial cells via signal transduction events in the presence of β₂GPI. Impaired fibrinolysis has been reported in patients with APS. Using a newly developed chromogenic assay, we demonstrated lower activity of intrinsic fibrinolysis in euglobulin fractions from APS patients. Addition of monoclonal anti-β₂GPI antibodies with β₂GPI also decreased fibrinolytic activity in this assay system. β₂GPI is proteolytically cleaved by plasmin in domain V (nicked β₂GPI) and becomes unable to bind to phospholipids, reducing antigenicity against antiphospholipid antibodies. This cleavage occurs in patients with increased fibrinolysis turnover. Nicked β₂GPI binds to plasminogen and suppresses plasmin generation in the presence of fibrin, plasminogen, and tissue plasminogen activator (tPA). Thus, nicked β₂GPI plays a role in the extrinsic fibrinolysis via a negative feedback pathway loop.     

Exogenous expression of interferon-beta in cultured brain microvessel endothelial cells

Brain microvessel endothelial cells (BMECs) make up the blood-brain barrier (BBB) and regulate the passage of therapeutic proteins as well as drugs from the cerebrovasucular circulation to the brain. In the present study, we transferred mouse or human interferon-beta (IFN-beta) gene via cationic liposomes into primary cultures of bovine BMECs developed as an in vitro model of the BBB. The gene-transferred BMECs secreted transiently a substantial amount of IFN activity more efficiently during the growth phase than at confluence. This was suggested to be due to a difference in the potential for plasmid incorporation between growing and confluent BMECs in a series of cell association experiments with (32)P-labelled plasmid DNA. Furthermore, when BMEC monolayers in Transwell plates were transfected with the IFN-beta-expression vectors from the upper side, IFN-beta was predominantly detected in the upper compartments, suggesting polarized secretion of the transgene products in BMEC monolayers. These findings provide important basic information about therapeutic secretory protein gene delivery to BMECs.     

An integrative model of binocular vision: a stereo model utilizing interocularly unpaired points produces both depth and binocular rivalry

Half-occluded points (visible only in one eye) are perceived at a certain depth behind the occluding surface without binocular rivalry, even though no disparity is defined at such points. Here we propose a stereo model that reconstructs 3D structures not only from disparity information of interocularly paired points but also from unpaired points. Starting with an array of depth detection cells, we introduce cells that detect unpaired points visible only in the left eye or the right eye (left and right unpaired point detection cells). They interact cooperatively with each other based on optogeometrical constraints (such as uniqueness, cohesiveness, occlusion) to recover the depth and the border of 3D objects. Since it is contradictory for monocularly visible regions to be visible in both eyes, we introduce mutual inhibition between left and right unpaired point detection cells. When input images satisfy occlusion geometry, the model outputs the depth of unpaired points properly. An interesting finding is that when we input two unmatched images, the model shows an unstable output that alternates between interpretations of monocularly visible regions for the left and the right eyes, thereby reproducing binocular rivalry. The results suggest that binocular rivalry arises from the erroneous output of a stereo mechanism that estimates the depth of half-occluded unpaired points. In this sense, our model integrates stereopsis and binocular rivalry, which are usually treated separately, into a single framework of binocular vision. There are two general theories for what the "rivals" are during binocular rivalry: the two eyes, or representations of two stimulus patterns. We propose a new hypothesis that bridges these two conflicting hypotheses: interocular inhibition between representations of monocularly visible regions causes binocular rivalry. Unlike the traditional eye theory, the level of the interocular inhibition introduced here is after binocular convergence at the stage solving the correspondence problem, and thus open to pattern-specific mechanisms.     

Profiles of polychlorinated biphenyl congeners, organochlorine pesticides, and butyltins in southern sea otters and their prey

Concentrations of organochlorine pesticides, polychlorinated biphenyl (PCB) congeners, and butyltins were measured in sea otters and selected prey species (invertebrates) collected from the California (USA) coast. Polychlorinated biphenyls, DDTs (sum of p,p'-dichlorodiphenyldichloroethylene [p,p'-DDE], p,p'-dichlorodiphenyldichloroethane [p,p'-DDD], and p,p'-DDT), and butyltins were the major contaminants found in sea otters and their prey. Lipid-normalized concentrations of PCBs and DDT in sea otter livers were 60- and 240-fold greater than those found in the prey. Great biomagnification of PCBs and DDT in sea otters is suggested to result from their high per-capita intake of diet compared with those of other marine mammals. Profiles of PCB congeners in sea otters and prey species suggest a great capacity of sea otters to biotransform lower-chlorinated congeners. Sea otters seem to possess a greater ability than cetaceans to metabolize PCBs. The 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents of non- and mono-ortho PCBs in sea otters and certain prey species were at or above the theoretical threshold for toxic effects.