Isolated Central Nervous System Involvement after Brentuximab Vedotin Treatment for HIV-Positive ALK-Negative Anaplastic Large Cell Lymphoma.

Human immunodeficiency virus (HIV)-associated lymphoma poses a high mortality risk despite antiretroviral therapy (ART). Although intermediate- or high-grade B-cell lymphomas are common, anaplastic large-cell lymphomas (ALCLs) are rare and seldom affect the central nervous system (CNS). Herein, we present a case of HIV-associated ALCL with isolated CNS involvement that occurred following the discontinuation of ART that was administered after treatment with brentuximab vedotin (BV)-which does not cross the blood-brain barrier. At the time of CNS recurrence, the patient's CD4 count was 9 cells/mm3. This is the first report of CNS recurrence in HIV-associated ALCL. Considering the high risk of CNS relapse, we suggest initiating CNS prophylaxis in cases of HIV-associated ALCL, particularly in patients receiving CNS-impermeable agents such as BV.

Pathological Characteristics of a Patient with Severe Fever with Thrombocytopenia Syndrome (SFTS) Infected with SFTS Virus through a Sick Cat's Bite.

A woman in her fifties showed symptoms of fever, loss of appetite, vomiting, and general fatigue 2 days after she was bitten by a sick cat, which had later died, in Yamaguchi prefecture, western Japan, in June 2016. She subsequently died of multiorgan failure, and an autopsy was performed to determine the cause of death. However, the etiological pathogens were not quickly identified. The pathological features of the patient were retrospectively re-examined, and the pathology of the regional lymph node at the site of the cat bite was found to show necrotizing lymphadenitis with hemophagocytosis. The pathological features were noted to be similar to those of patients reported to have severe fever with thrombocytopenia syndrome (SFTS). Therefore, the lymph node section was retrospectively tested immunohistochemically, revealing the presence of the SFTS virus (SFTSV) antigen. The sick cat showed similar symptoms and laboratory findings similar to those shown in human SFTS cases. The patient had no history of tick bites, and did not have skin lesions suggestive of these. She had not undertaken any outdoor activities. It is highly possible that the patient was infected with SFTSV through the sick cat's bite. If a patient gets sick in an SFTS-endemic region after being bitten by a cat, SFTS should be considered in the differential diagnosis.

Recurrent extramedullary relapse of acute myelogenous leukemia after allogeneic hematopoietic stem cell transplantation in a patient with the chromosomal abnormality t(8;21) and CD56-positivity.

Isolated extramedullary (EM) relapse of acute myelogenous leukemia (AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is rare. Predisposing factors include CD56 expression and the chromosomal abnormality t(8;21). We describe an AML patient showing the chromosomal abnormality t(8;21) and CD56 expression who experienced a unique EM relapse after allo-HSCT. Approximately 10 months after allo-HSCT, he experienced relapse involving the femur and lumbar vertebrae and, subsequently, an EM relapse of the stomach. Although we administered only local radiotherapy and not systemic chemotherapy, he showed no bone marrow relapse on long-term follow-up after achieving complete hematological remission. These findings suggest that the graft-versus-leukemia effect may preferentially maintain marrow remission rather than prevent EM relapse. In addition, our findings show that extended survival is possible after EM relapse following allo-HSCT in patients with marrow hematopoiesis of donor origin, and that augmentation of the graft-versus-leukemia effect may be useful.

Role of PKC isoforms in glucose transport in 3T3-L1 adipocytes: insignificance of atypical PKC.

To elucidate the involvement of protein kinase C (PKC) isoforms in insulin-induced and phorbol ester-induced glucose transport, we expressed several PKC isoforms, conventional PKC-alpha, novel PKC-delta, and atypical PKC isoforms of PKC-lambda and PKC-zeta, and their mutants in 3T3-L1 adipocytes using an adenovirus-mediated gene transduction system. Endogenous expression and the activities of PKC-alpha and PKC-lambda/zeta, but not of PKC-delta, were detected in 3T3-L1 adipocytes. Overexpression of each wild-type PKC isoform induced a large amount of PKC activity in 3T3-L1 adipocytes. Phorbol 12-myristrate 13-acetate (PMA) activated PKC-alpha and exogenous PKC-delta but not atypical PKC-lambda/zeta. Insulin also activated the overexpressed PKC-delta but not PKC-alpha. Expression of the wild-type PKC-alpha or PKC-delta resulted in significant increases in glucose transport activity in the basal and PMA-stimulated states. Dominant-negative PKC-alpha expression, which inhibited the PMA activation of PKC-alpha, decreased in PMA-stimulated glucose transport. Glucose transport activity in the insulin-stimulated state was increased by the expression of PKC-delta but not of PKC-alpha. These findings demonstrate that both conventional and novel PKC isoforms are involved in PMA-stimulated glucose transport and that other novel PKC isoforms could participate in PMA-stimulated and insulin-stimulated glucose transport. Atypical PKC-lambda/zeta was not significantly activated by insulin, and expression of the wild-type, constitutively active, and dominant-negative mutants of atypical PKC did not affect either basal or insulin-stimulated glucose transport. Thus atypical PKC enzymes do not play a major role in insulin-stimulated glucose transport in 3T3-L1 adipocytes.

Role of PDK1 in insulin-signaling pathway for glucose metabolism in 3T3-L1 adipocytes.

To investigate the role of 3-phosphoinositide-dependent protein kinase 1 (PDK1) in the insulin-signaling pathway for glucose metabolism, wild-type (wt), the kinase-dead (kd), or the plecstrin homology (PH) domain deletion (DeltaPH) mutant of PDK1 was expressed using an adenovirus gene transduction system in 3T3-L1 adipocytes. wt-PDK1 and kd-PDK1 were found in both membrane and cytosol fractions, whereas DeltaPH-PDK1, which exhibited PDK1 activity similar to that of wt-PDK1, was detected exclusively in the cytosol fraction. Insulin dose dependently activated protein kinase B (PKB) but did not change atypical protein kinase C (aPKC) activity in control cells. aPKC activity was not affected by expression of wt-, kd-, or DeltaPH-PDK1 in either the presence or the absence of insulin. Overexpression of wt-PDK1 enhanced insulin-induced activation of PKB as well as insulin-induced phosphorylation of glycogen synthase kinase (GSK)3alpha/beta, a direct downstream target of PKB, although insulin-induced glycogen synthesis was not significantly enhanced by wt-PDK1 expression. Neither DeltaPH-PDK1 nor kd-PDK1 expression affected PKB activity, GSK3 phosphorylation, or glycogen synthesis. Thus membrane localization of PDK1 via its PH domain is essential for insulin signaling through the PDK1-PKB-GSK3alpha/beta pathway. Glucose transport activity was unaffected by expression of wt-PDK1, kd-PDK1, or DeltaPH-PDK1 in either the presence or the absence of insulin. These findings suggest the presence of a signaling pathway for insulin-stimulated glucose transport in which PDK1 to PKB or aPKC is not involved.