Two cases of polymorphic ventricular tachycardia induced by the administration of verapamil against paroxysmal supraventricular tachycardia

Verapamil is widely used for the termination of paroxysmal supraventricular tachycardia (PSVT) with little proarrhythmic effect. We describe two cases of PSVT that changed to non-sustained polymorphic ventricular tachycardia after administration of verapamil. Electrophysiological study revealed atrioventricular nodal reentrant tachycardia in the first case, and atrioventricular reentrant tachycardia due to a concealed left lateral accessory pathway in the second case. Catecholamine-induced automaticity was one of the possible mechanisms of VT in the first case, but the mechanism is unknown in the second case.     

Expression of GPIV and Naka antigen on monocytes in Naka-negative subjects whose platelets lack GPIV

Summary. The platelet antigen Nak^a was once considered to be a platelet-specific alloantigen and is carried on platelet membrane glycoprotein (GP) IV. Recent studies suggest that Nak^a-negative subjects lack platelet GPIV. GPIV is an important adhesive receptor and expressed on the surface of monocytes as well as of platelets. In the present study, flow cytometry was used to detect GPIV and Nak^a antigen on the surface of monocytes. Nak^a antigen was expressed on monocytes as well as on platelets in Nak^a-positive subjects ( n = 6) (P-GPIV-positive subjects). To our surprise, monocytes of Nak^a-negative subjects ( n = 7) (P-GPIV-negative subjects) having no anti-Nak^a antibody in their serum expressed GPIV and Nak^a antigen to almost the same degree as did the monocytes of P-GPIV-positive subjects. Competitive experiments using OKM5 (a monoclonal antibody against GPIV) and anti-Nak^a antibody showed that the epitope of anti-Nak^a antibody on monocytes was very close to that of OKM5. In two P-GPIV-negative subjects having anti-Nak^a antibody in their serum, GPIV and Nak^a antigen were not expressed on the surface of either monocytes or platelets. These results indicate that the GPIV molecules and Nak^a antigen are expressed on the surface of monocytes in the majority of P-GPIV-negative subjects, but that in a very few P-GPIV-negative subjects neither GPIV nor Nak^a antigen is expressed on the surface of their monocytes. We hypothesize that P-GPIV-negative subjects who carry neither GPIV nor Nak^a antigen on their monocytes produce anti-Nak^a antibody as a result of transfusion or pregnancy.     

Chronic persistent Epstein-Barr virus infection of natural killer cells and B cells associated with granular lymphocytes expansion

B lymphocytes and epithelial cells are the only cell types known to be infected with Epstein-Barr virus (EBV) in normal individuals. Rarely, EBV also infects other cells, including natural killer (NK) cells, almost always in the context of fatal leukaemias or lymphoproliferative disorders. We report on a 6-year-old previously healthy girl who developed fevers and liver function abnormalities for 3 months. The peripheral blood revealed an abnormal expansion of large granular lymphocytes, comprising 24% of the white blood cells. Flow cytometric analysis of the peripheral blood mononuclear cells showed an abnormal increase of CD16-positive NK cells, 62% of which were EBV-infected by in situ EBER-1 hybridization. The circulating B cells were normal in number, but 18% were infected with EBV by in situ EBER-1 hybridization. Approximately 2 years after resolution of all symptoms and continued good health, 35% of the circulating mononuclear cells were EBV-infected, indicative of persistent expansion of EBV-infected cells. We conclude that abnormal expansions of EBV-infected NK and B cells can be associated with a chronic benign course.     

Utility of a simplified ultrasonography scoring system among patients with rheumatoid arthritis: A multicenter cohort study

We aimed to evaluate the utility of a simplified ultrasonography (US) scoring system, which is desired in daily clinical practice, among patients with rheumatoid arthritis (RA) receiving biological/targeted synthetic disease-modifying antirheumatic drugs (DMARDs).A total of 289 Japanese patients with RA who were started on tumor necrosis factor inhibitors, abatacept, tocilizumab, or Janus kinase inhibitors between June 2013 and April 2019 at one of the 15 participating rheumatology centers were reviewed. We performed US assessment of articular synovia over 22 joints among bilateral wrist and finger joints, and the 22-joint (22j)-GS and 22-joint (22j)-PD scores were evaluated as an indicator of US activity using the sum of the GS and PD scores, respectively.The top 6 most affected joints included the bilateral wrist and second/third metacarpophalangeal joints. Therefore, 6-joint (6j)-GS and -PD scores were defined as the sum of the GS and PD scores from the 6 synovial sites over the aforementioned 6 joints, respectively. Although the 22j- or 6j-US scores were significantly correlated with DAS28-ESR or -CRP scores, the correlations were weak. Conversely, 6j-US scores were significantly and strongly correlated with 22j-US scores not only at baseline but also after therapy initiation.Using a multicenter cohort data, our results indicated that a simplified US scoring system could be adequately tolerated during any disease course among patients with RA receiving biological/targeted synthetic DMARDs.     

A case of severe recurrent hepatitis with common variable immunodeficiency.

Severe hepatitis with an indistinct etiology manifested in a 16-year-old boy who had no particular history. The histological features of the liver and clinical course of the patient were similar to those of patients with autoimmune hepatitis characterized by interface hepatitis and severe lobular inflammation of the liver and recurrent exacerbations of hepatitis. We administered intravenous glycyrrhizin preparation daily or three times a week combined with the oral administration of ursodeoxycholic acid daily throughout the term after the initial onset of disease for the control of disease activity. The normalization of the concentration of alanine aminotransferase in serum was achieved in response to the therapy during the course. The serum concentration of immunoglobulins of the patient gradually decreased from the onset of the disease to an unacceptable level without globulin preparation during the following period of 17 months. Immunological tests revealed impairment of immunoglobulin production bythe B cell population of the patient, which led to the diagnosis of the patient as common variable immunodeficiency (CVID). The patient, with improved liver histology after 27 months from the onset of disease, benefited from the current combination therapy without severe infection through the avoidance of overimmunosuppression. CVID is defined as a heterogeneous syndrome characterized by various degrees of hypogammaglobulinemia without any specific predisposing causes, frequently associated with autoimmunity. Diagnostic criteria and therapeutic options of persistent hepatitis with CVID are to be established, as discussed in the current report.     

Pediatric myositis ossificans mimicking osteosarcoma

Myositis ossificans (MO) is a rare benign cause of heterotopic bone formation in soft tissue that most commonly affects young adults, typically following trauma. We report the case of an 11‐year‐old girl who developed MO mimicking osteosarcoma in her right shoulder. Plain radiography and computed tomography showed poorly defined flocculated densities in the soft tissue and a periosteal reaction along the proximal humerus. On magnetic resonance imaging, the mass displayed an ill‐defined margin and inhomogeneous signal change. Histologically, the mass had a pseudosarcomatous appearance. Based on these findings, the patient was initially misdiagnosed with osteosarcoma at another hospital. The diagnosis was difficult because the patient was 11 years old and had no trauma history, with atypical radiographic changes and a predilection for the site of origin for osteosarcomas. We finally made the correct diagnosis of MO by carefully reviewing and reflecting on the pathological differences between stages.     

Involvement of central metastin in the regulation of preovulatory luteinizing hormone surge and estrous cyclicity in female rats

Ovulation is caused by a sequence of neuroendocrine events: GnRH and LH surges that are induced by positive feedback action of estrogen secreted by the mature ovarian follicles. The central mechanism of positive feedback action of estrogen on GnRH/LH secretion, however, is not fully understood yet. The present study examined whether metastin, the product of metastasis suppressor gene KiSS-1, is a central neuropeptide regulating GnRH/LH surge and then estrous cyclicity in the female rat. Metastin had a profound stimulation on LH secretion by acting on the preoptic area (POA), where most GnRH neurons projecting to the median eminence are located, because injection of metastin into the third ventricle or POA increased plasma LH concentrations in estrogen-primed ovariectomized rats. Metastin neurons were immunohistochemically found in the arcuate nucleus (ARC) to be colocalized with estrogen receptors with some fibers in the preoptic area (POA) in close apposition with GnRH neuronal cell bodies or fibers. Quantitative RT-PCR has revealed that KiSS-1 and GPR54 mRNAs were expressed in the ARC and POA, respectively. The blockade of local metastin action in the POA with a specific monoclonal antibody to rat metastin completely abolished proestrous LH surge and inhibited estrous cyclicity. Metastin-immunoreactive cell bodies in the ARC showed a marked increase and c-Fos expression in the early proestrus afternoon compared with the day of diestrus. Thus, metastin released in the POA is involved in inducing the preovulatory LH surge and regulating estrous cyclicity.