Idiopathic Reentrant Right Ventricular Outflow Tract Tachycardia With Presystolic Potential of Central Pathway

Idiopathic Reentrant RVOT VT With Presystolic Potential . A 12‐year‐old girl with recurrent palpitation due to idiopathic ventricular tachycardia (VT) with a left bundle branch block configuration and inferior axis was referred to our hospital. During the VT, a spiky presystolic potential (SP) was recorded at the septum of right ventricular outflow tract (RVOT) just below pulmonary valve. The SP was entrained with a decremental property by pacing from right ventricular apex. Concealed entrainment was observed by pacing where the SP was recorded. Delivery of radiofrequency current targeting the SP abolished the VT. The SP with the decremental property could represent the central pathway of this idiopathic RVOT reentrant VT. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1174‐1177)     

Abrupt Heart Rate Fallings in a Patient with Biventricular Pacing: Latent Risk for Exacerbation of Heart Failure

This case report describes abrupt heart rate fallings below the lower pacing rate limit in a patient with cardiac resynchronization therapy (CRT). Interrogated information including stored episodes or data regarding the lead did not show any device problems and only simultaneous intracardiac electrogram revealed the cause, T‐wave oversensing during biventricular pacing. At this moment, CRT has become an established modality for patients with severe heart failure. However, bradycardia below the lower rate limit during biventricular pacing due to T‐wave oversensing would exacerbate heart failure in patients with CRT. We should notice this latent risk and correct the malfunction immediately. (PACE 2010; 1–4)     

FACTORS RELATED TO LATERAL MARGIN POSITIVITY FOR CANCER IN GASTRIC SPECIMENS OF ENDOSCOPIC SUBMUCOSAL DISSECTION

Background: With the widespread use of endoscopic submucosal dissection (ESD), more large early gastric cancers (EGC) have become candidates for endoscopic resection. A precise diagnosis of the extent of cancer is indispensable to obtain R0 resection. The aim of the present study was to clarify the factors related to lateral margin positivity for cancer in specimens resected by ESD for EGC. Methods: Among 1549 EGC treated by ESD during September 2002 to December 2008, lesions that were resected in an en‐bloc fashion and resulted in a pathological diagnosis of lateral margin positive (LM+) for cancer, were extracted. The reason for LM+ and pathological characteristics of the lesions were studied and compared to lesions successfully resected with margins negative for cancer. Results: There were three types of lesion that resulted in LM+ resection: lesions with a flat spreading area, lesions with an unexpected nearby lesion, and lesions with lateral extension beneath a non‐cancerous mucosa. Compared to lesions resected with margins negative for cancer, diameter of the tumor, recurrent‐type cancer, submucosal cancer, and undifferentiated‐type cancer were factors significantly related to LM+ resection. Conclusion: Other than misdiagnosing a small portion of cancer extension, lateral margin positivity for cancer by ESD could result from a neighboring lesion and an unexpected lateral submucosal cancer extension. To avoid LM+ resection of EGC by ESD, one should be careful of unexpected lateral extension and simultaneous multi‐lesions.     

CASE REPORT: A patient who developed an amoebic liver abscess during treatment with interferon

A 65-year-old female received recombinant interferon (IFN) α-2b daily for the treatment of chronic hepatitis C. Fever (39°C or higher) developed 14 days after the start of administration. Abdominal computed tomography suggested multiple liver abscesses, which had not been detected before IFN administration. An autopsy revealed an amoebic liver abscess. A subclinical infection of Entamoeba histolytica in this case developed into amoebic liver abscess during IFN administration.     

A Case of a Pseudomalfunction of a DDD Pacemaker

DDD pacemaker pseudomalfunction occurred in a 65-year-old man. This was due to premature ventricular contraction (PVC) response option and cross-talk detection window, which are designed to protect against pacemaker related tachycardia or cross-talk. Pseudomalfunction disappeared by eliminating PVC response option.     

Age-related occurrence of inhibitory antibodies to streptococcal pyrogenic superantigens

Several bacteria, such as staphylococci and streptococci, can produce superantigens (SA) that induce the activation of T cells in humans. Although these organisms are the major causes of infection in children, the evidence that T cells are vigorously activated by SA produced by such organisms has not been reported except for toxic shock syndrome. In a previous paper, we demonstrated that inhibitory IgG antibodies (Ab) to SA in humans may protect against SA stimulation. In the present study, we investigated the occurrence of these inhibitory Ab to SA in 94 healthy children by the enzyme linked immunosorbent assay technique and the suppressive effect on T cell stimulation by SA. The positivity of Ab to streptococcal pyrogenic exotoxin (SPE)-A, SPE-C and staphylococcal enterotoxin B (SEB) increased with age. The age at which more than 50% of children exhibited Ab to SA was 1 year for SEB, 6 years for SPE-C and 11 years for SPE-A. Sera from these children were inhibitory to T cell proliferation elicited by SA in proportion to the concentration of IgG Ab to each SA. Sera supplemented with IgG Ab to SA by gamma-globulin therapy became inhibitory to T cell proliferation by SA. We conclude that, as children grow, they can develop Ab to SA that may play a role in protecting them against vigorous T cell activation by SA.     

Epithelial cell proliferation during colonic chemical carcinogenesis in the rat

To define the significance of alterations in epithelial cell proliferation as a marker of high risk mucosa for colorectal cancer, we examined cell proliferative events in the colonic mucosa during chemical carcinogenesis using in vitro bromodeoxyuridine labelling and by analysing serial colonoscopic biopsy specimens from dimethylhydrazine (DMH)-treated rats. In both the rectum and flexure of the colon, an increased labelling index of colonic epithelial cells, an upward extension of the proliferating zone and an upward shift of the major area of DNA synthesis of epithelial cells were observed during DMH-induced colonic carcinogenesis in rats. These changes preceded the development of the colonic tumour and were observed in endoscopically normal rectal mucosa where the tumour was absent. We confirmed the altered cell proliferative events preceding the development of the tumour by examining serial colonoscopic biopsies. The results suggest that these alterations are features that identify premalignant colonic mucosa in DMH-treated rats.