Double Atrial Potentials Recorded in the Coronary Sinus in Patients with Wolff-Parkinson-White Syndrome: A Possible Mechanism of Induced Atrial Fibrillation

BACKGROUND: Double atrial potentials recorded in the coronary sinus are not an unusual phenomenon in patients with supraventricular tachyarrhythmias. They have been demonstrated to potentiate the occurrence of atrial tachyarrhythmias. METHODS: Two hundred and forty-eight patients were included for investigating the presence of double atrial potentials on the coronary sinus recordings during electrophysiologic study. Group 1 consisted of 136 patients with WPW syndrome and group 2 consisted of 112 patients with atrioventricular nodal reentrant tachycardia (AVNRT). Group 1 patients had a higher incidence of induced atrial fibrillation (AF) (27% vs. 15%, P = 0.045) than group 2 patients. In addition, the incidence of double atrial potentials was significantly higher in group 1 than in group 2 patients (14% vs. 2%, P = 0.001). In group 1, 19 patients with double atrial potentials had a significantly higher incidence of left lateral bypass tracts (79% vs. 39%, P = 0.001) and induced AF (47% vs. 22%, P = 0.01) than 117 patients without double atrial potentials. CONCLUSIONS: WPW syndrome, especially with a left lateral bypass tract, had a higher incidence of double atrial potentials and induced AF than AVNRT. WPW patients with double atrial potentials had a higher incidence of induced AF than those without double atrial potentials. These findings may contribute to understanding the mechanism of induced AF in WPW syndrome.     

A family of secreted proteins contains homology to the cysteine-rich ligand-binding domain of frizzled receptors

This paper describes the identification of a new family of mammalian genes that encode secreted proteins containing homology to the cysteine-rich ligand-binding domain found in the frizzled family of transmembrane receptors. The secreted frizzled-related proteins (sFRPs) are approximately 30 kDa in size, and each contains a putative signal sequence, a frizzled-like cysteine-rich domain, and a conserved hydrophilic carboxy-terminal domain. The sFRPs are not the products of differential splicing of the known frizzled genes. Glycosylphosphatidylinositol-anchored derivatives of sFRP-2 and sFRP-3 produced in transfected human embryonic kidney cells confer cell-surface binding by the Drosophila Wingless protein. These observations suggest that sFRPs may function in vivo to modulate Wnt signaling, or, alternatively, as novel ligands for as yet unidentified receptors.     

Infection of human T-cell leukemia virus type I and development of human T-cell leukemia lymphoma in patients with hematologic neoplasms: a possible linkage to blood transfusion

Among 354 adult patients with either hematological malignancy or aplastic anemia, eight were positive for anti-HTLV-I antibodies; six of eight had received multiple transfusions. There was an approximately 3.5-fold increase (P less than .001) of HTLV-I seropositivity in the patients with hematologic disease (8 of 354, 2.23%) compared to the healthy adults older than 20 years (34 of 5252, .65%). Two hematological patients, one with Hodgkin's disease and one with acute promyelocytic leukemia, were found to be positive for HTLV-I, and developed and died of adult T-cell leukemia/lymphoma (ATL) subsequently. Both were long-term survivors of the primary disease and had received multiple transfusions. The latent period from blood transfusion to onset of ATL was 6 months and 11 years, respectively. Immunocompromised patients, who were seropositive for HTLV-I, may be at increased risk for ATL compared to healthy carriers of HTLV-I, and the latent period may be shorter.     

Value of CT in the diagnosis and management of gallstone ileus

AIM: To retrospectively establish the diagnostic criteria of gallstone ileus on CT, and to prospectively apply these criteria to determine the diagnostic accuracy of CT to confirm or exclude gallstone ileus in patients who presented with acute small bowel obstruction (SBO). Another purpose was to ascertain whether the size of ectopic gallstones would affect treatment strategy. METHODS: Fourteen CT scans in cases of proved gallstone ileus were evaluated retrospectively by two radiologists for the presence or absence of previously reported CT findings to establish the diagnostic criteria. These criteria were applied in a prospective contrast enhanced CT study of 165 patients with acute SBO, which included those 14 cases of gallstone ileus. The hard copy images of 165 CT studies were reviewed by a different group of two radiologists but without previous knowledge of the patient's final diagnosis. All CT data were further analyzed to determine the diagnostic accuracy of gallstone ileus when using CT in prospective evaluation of acute SBO. The size of ectopic gallstone on CT was correlated with the clinical course. RESULTS: The diagnostic criteria of gallstone ileus on CT were established retrospectively, which included: (1) SBO; (2) ectopic gallstone; either rim-calcified or total-calcified; (3) abnormal gall bladder with complete air collection, presence of air-fluid level, or fluid accumulation with irregular wall. Prospectively, CT confirmed the diagnosis in 13 cases of gallstone ileus with these three criteria. Only one false negative case could be identified. The remaining 151 patients are true negative cases and no false positive case could be disclosed. The overall sensitivity, specificity and accuracy of CT in diagnosing gallstone ileus were 93%, 100%; and 99%, respectively. Surgical exploration was performed in 13 patients of gallstone ileus with ectopic stones sized larger than 3 cm. One patient recovered uneventfully following conservative treatment with an ectopic stone sized 2 cm in the long axis. CONCLUSION: Contrast enhanced CT imaging offered crucial evidence not only for the diagnosis of gallstone ileus but also for decision making in management strategy.     

Aberrant co-expression of CD19 and CD56 as surrogate markers of acute myeloid leukemias with t(8;21) in Taiwan

Aberrant antigen expression in acute myeloid leukemia (AML) has been extensively studied in the West with limited reports from Taiwan. We carried out this retrospective study to characterize the frequency and significance of aberrant antigen expression of AML in Taiwan. Among 111 cases, 58 (52%) showed aberrant antigen expression, most frequently CD7 (27%) and CD56 (23%). Aberrant CD7 expression was observed in all non-AML-M3 subtypes, most frequently in AML-M7 (4/6, 67%); while CD19 expression was only observed in AML-M2 (5/36, 14%). CD56 expression was most common in AML-M5 (4/8, 50%). The relative frequency of CD19 and CD56 expression in AML with t(8;21) was higher than those with other chromosomal abnormalities or normal karyotype (P = 0.011 and 0.005, respectively). In non-M3 AML, aberrant antigen expression was identified in 56/96 (58%) cases, in contrast to 2/15 (13%) AML-M3 cases (P = 0.001). CD7, CD19 and CD56 expression was not correlated with remission rate. We concluded that aberrant immunophenotype was more frequent in non-M3 leukemias in Taiwan. The relative frequency of CD19 and/or CD56 expression in AML with t(8;21) was significantly higher than those without this translocation and co-expression of these two antigens may serve as the surrogate markers for AML with t(8;21).     

Late initiation of continuous veno-venous hemofiltration therapy is associated with a lower survival rate in surgical critically ill patients with postoperative acute kidney injury

There is controversy about the appropriate timing for renal replacement therapy in patients with acute kidney injury (AKI). We are interested in the appropriate timing for initiation of continuous renal replacement therapy in critically ill surgical patients with postoperative acute kidney injury. Seventy-three critically ill surgical patients with postoperative AKI who received continuous renal replacement therapy (CRRT) were enrolled. Indications for CRRT were: 1) AKI with hyperkalemia, 2) metabolic acidosis, 3) pulmonary edema refractory to diuretics, and 4) oliguria with progressive azotemia, especially in unstable hemodynamics. Using RIFLE (Risk, Injury, Failure, Loss, End stage) classification, patients who received CRRT in the "Risk" stage were defined as early group, whereas those in the "Injury/ Failure" stage were labeled as late group. We used continuous veno-venous hemofiltration as CRRT in this series. There were 20 patients in the early group and 53 patients in the late group. The mean ages were 61.5 ± 21.8 years versus 60.8 ± 17.5 years. The mortality rate was 50 per cent versus 84.9 per cent. There were no significant differences in demographic characteristics or type of surgery or physiological scores. Our data show that late initiation of CRRT is associated with a lower survival rate in critically ill surgical patients with postoperative AKI; however, further studies are required.