Doppler tissue analysis of atrial electromechanical coupling in paroxysmal atrial fibrillation.

The aim of this study was to: (1) evaluate atrial electromechanical coupling using M-mode Doppler tissue; and (2) test its clinical impact for detecting atrial abnormalities in paroxysmal atrial fibrillation (AF). Using Doppler tissue, the time intervals from the onset of P wave until the backward motions of the right and left atrioventricular rings in the apical 4-chamber view corresponding to the atrial contractions were measured. In paroxysmal AF group, these intervals were significantly longer than in the control group. Using the criteria that an abnormal time interval from the onset of P wave until the backward motion of the left atrioventricular ring is longer than 112 milliseconds, the sensitivity, the specificity, and the positive predictive values for paroxysmal AF are 73%, 93%, and 93%, respectively. This parameter is affected in patients with paroxysmal AF and should be useful for detecting atrial impairment related to paroxysmal AF.     

Membrane Fas Ligand Kills Human Peripheral Blood T Lymphocytes, and Soluble Fas Ligand Blocks the Killing

It has been believed that the Fas expressed on human peripheral blood T cells (PBT) is nonfunctional, because these cells are insensitive to agonistic anti-Fas/Apo-1 mAbs that efficiently kill in vitro–activated T cells and many Fas-expressing cell lines. Here, we demonstrate that membrane-bound Fas ligand (FasL) kills both fresh and in vitro–activated PBT, indicating that the Fas expressed on fresh PBT is functional. In contrast, soluble FasL kills only the latter. Naive T cells in umbilical cord blood do not express Fas, but can be induced to express Fas by IFN-γ or by a combination of IL-2 and anti-CD28 mAb, after which they acquire sensitivity to membrane but not to soluble FasL. Soluble FasL inhibited the killing of fresh PBT by membrane FasL. These results indicate that the shedding of FasL from the membrane is a mechanism for downregulating at least part of its killing activity.     

Modulatory effect of roxithromycin on human neutrophil function

Neutrophils are thought to play a key role in tissue injury. We investigated the effect of roxithromycin, a 14-membered ring macrolide, on human neutrophil functions. The drug inhibitedN-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced superoxide (O ₂ ^? ) production and Ca²⁺ influx of human neutrophils. The inhibition was overcome by adding an inhibitor of cyclic AMP-dependent protein kinase (PKA), H-89. These results suggest that the drug affects O ₂ ^? production and intracellular Ca²⁺ concentration of neutrophils via the action of PKA. Moreover, roxithromycin ameliorated endothelial cell injury induced by neutrophils, which may be, in part, due to the effect of the drug on neutrophils. Thus, roxithromycin may contribute to the treatment of diseases worsened by the excessive action of neutrophils.     

Continuous monitoring of ventilatory mechanics during one-lung ventilation

Objective. The Ultima SV respiratory monitor can be used to monitor the intraoperative effects of the lateral decubitus position and one-lung ventilation on ventilatory mechanics.Methods. Eight patients with esophageal cancer who required one-lung ventilation for esophagectomy and reconstruction were enrolled in the study. We monitored pressure-volume or flow-rate-volume loops continuously throughout the operation. Respiratory parameters were evaluated closely during five conditions of ventilation: two-lung ventilation in the supine position, two-lung ventilation in the lateral decubitus position, dependent one-lung ventilation in the lateral decubitus position, nondependent one-lung ventilation in the lateral decubitus position, and dependent one-lung ventilation in the lateral decubitus position with the chest opened. Respiratory rate was controlled at 10 breaths/min, and tidal volume was kept constant (10 ml/kg) during surgery.Results. Peak inspiratory pressure increased to 29.0 ± 9.0 (mean ± SD) cm H₂O in the dependent one-lung in the lateral decubitus position with the chest opened (p < 0.01). Dynamic compliance decreased to 29.4 ± 4.9 ml/cm H₂O in the dependent one-lung in the lateral decubitus position with the chest opened (p < 0.01). The changing configuration of the loops also offered additional and instantaneous information during one-lung ventilation.Conclusions. One-lung ventilation caused several changes in the whole respiratory system (lung, thorax, and endotracheal tube). Continuous monitoring of flow-rate-volume or pressure-volume loops with in-line spirometry provided comprehensive information regarding parameters in one-lung ventilation.     

Present state and measures of Barrett's cancer in Japan

Barrett's adenocarcinoma is common esophageal cancer in western countries but very rare in Japan. We reviewed 206 cases of Barrett's cancer in Japanese literature that issued from 2000 to 2004. 80% of them were superficial cancer. There was no mucosal Barrett's cancer with lymph nodes metastasis, therefore EMR (endoscopic mucosal resection) method is an appropriate way for mucosal cancer. Barrett's cancer with submucosal invasion occur lymph nodes metastasis, so surgical operation should be applied for deeper invasion to submucosal cancer.     

A protective effect of coenzyme Q10 on ischemia and reperfusion of the isolated perfused rat heart

Experiments were undertaken to determine if pretreating the animal with coenzyme Q₁₀ (CoQ) protected the cardiac muscle of the isolated perfused heart which was exposed to global ischemia for 30 min and then reperfusion.Two hours after the intramuscular (20 mg/kg) and intraperitoneal (10 mg/kg) injections of CoQ or vehicle alone the hearts were excised and perfused by Langendorff's technique. In the vehicle-pretreated group, ischemia caused a precipitous decline of the contractile tension development, an elevation of the resting tension and a severe contracture. During the substrate-free reperfusion for 30 min, there was a small decrease in the magnitude (25%) of the contracture, and, yet, no tension development. In the additional reperfusion with glucose as the substrate for 30 min, the tension development was slightly (11%) recovered. Tissue ATP and total adenine nucleotide contents at the end of the glucosereperfusion markedly decreased. Although pretreatment with CoQ had no effect on the onset and progression of ischemic contracture, it facilitated the recovery of mechanical performance. Cardiac stores of both ATP and total adenine nucleotide in CoQ-pretreated reperfused hearts were significantly (P < 0.01) higher than those in vehicle-pretreated group. There was a direct relation between the extent of the recovery of mechanical performance and tissue ATP content.It was suggested that exogenous CoQ protected the cardiac muscle from the deterioration of mechanical function of ischemia and recovery. Better mechanical function of CoQ-pretreated heart was attributable to better resynthesis of ATP presumably due to lesser loss of adenine nucleotide pool from the cardiac cells.     

Clinical characteristics of Japanese reflux esophagitis patients as determined by Los Angeles classification

BACKGROUND: Recent studies have shown that the number of patients with reflux esophagitis is increasing in Japan, but the prevalence and risk factors associated with reflux esophagitis in Japanese patients are not well defined. METHODS: By using all endoscopic records in the Katta General Hospital from April through to September 1999, we identified 392 patients. We examined the Los Angeles classification, peptic ulcer, gastric mucosal atrophy, hiatal hernia and other medical variable factors for their contribution to esophagitis in the patients. RESULTS: Patients (13.8%) were diagnosed as having reflux esophagitis with a mucosal break. In a multivariate analysis, reflux esophagitis was associated with hiatal hernia (odds ratio (OR) 2.276, 95% confidence interval (CI) 1.164-4.450), with patients over 65 years of age (OR 2.521, 95% CI 1.238-5.134) and the open type of gastric mucosal atrophy (OR 0.420, 95% CI 0.225-0.785). There was no significant difference between esophagitis and Helicobacter pylori infection and peptic ulcer. CONCLUSIONS: We observed that age, hiatal hernia and a lower rate of gastric mucosal atrophy were associated with the proportion of mucosal breaks accompanying esophagitis.     

Accuracy of Implant Positioning for Minimally Invasive Total Knee Arthroplasty in Patients With Severe Varus Deformity

Minimally invasive surgery (MIS) in total knee arthroplasty (TKA) reportedly yields decreased patient morbidity and a rapid return of function, but how much deformity can be accepted for MIS-TKA remains unclear. This study investigated 238 knees from 218 consecutive patients who underwent MIS-TKA. Patients were divided into groups with tibiofemoral mechanical axis (TFM) 195° or greater and TFM less than 195°, then clinical and radiographic results were compared. Similar improvements in knee score at 3 months postoperatively were obtained in the both groups, whereas radiographic accuracy of the coronal alignment in the TFM ≥195° group was inferior to that in TFM <195° group. Postoperative TFM was significantly worsened in patients with lateral bowing angle of the femoral shaft (LBFS) 4° or greater, and 53% of patients in the TFM ≥195° group displayed LBFS 4° or greater, explaining the inferior radiographic accuracy in this group compared with the TFM <195° group. These results indicate that use of MIS techniques decreases radiographic accuracy, particularly in patients with severe genu varum and increased LBFS.