Mosquito salivary gland extracts induce EBV-infected NK cell oncogenesis via CD4 T cells in patients with hypersensitivity to mosquito bites

Severe hypersensitivity to mosquito bites (HMB) is characterized by intense local skin reactions and systemic symptoms such as high fever, lymphadenopathy, and hepatosplenomegaly. Patients with HMB often have natural killer (NK) cell lymphocytosis associated with Epstein-Barr virus (EBV) infection. Here we investigated whether mosquito bites have any influence on the oncogenesis of EBV-infected NK cells. We examined six HMB patients with EBV-infected NK cell lymphocytosis. We first demonstrated that CD4+ T cells, but not NK cells, proliferated well in response to mosquito salivary gland extracts (SGE), especially to SGE of Aedes albopictus. When NK cells were cocultured with autologous CD4+ T cells stimulated by mosquito SGE, the expression of viral oncogene latent membrane protein 1 (LMP1) was remarkably enhanced. Next, we stimulated mononuclear cells of the patients with mosquito SGE, and NK cell counts were monitored for 28 d. The counts changed little from initial levels in the culture with mosquito SGE, whereas they decreased steadily in the culture without the extracts. Furthermore, we detected LMP1 mRNA in the skin lesion induced by mosquito SGE. These results suggest that mosquito bites can induce expression of the viral oncogene LMP1 in NK cells via mosquito antigen-specific CD4+ T cells, which is involved in the oncogenesis of NK cells in vivo.     

Production of interleukin-2 and interleukin-2 inhibitor in patients with palmoplantar pustulosis

We studied production of interleukin-2 (IL-2) and IL-2 inhibitor from peripheral blood of patients with palmoplantar pustulosis (PPP). Nineteen patients were divided into two groups: those with and those without arthro-osteitis. Although IL-2 production in both groups of patients was within normal limits, those with arthro-osteitis showed greater fluctuation in relation to the disease activity. The IL-2 production of five PPP patients with arthro-osteitis was greatly enhanced in the inactive stage compared with the active stage. Sera from two patients treated with a combination of etretinate and colchicine contained extremely low levels of IL-2 inhibitory activity. The increased IL-2 production in the inactive stage may be due in part to the depletion of IL-2 inhibitor-producing cells by the treatment.     

Activation of c-Jun N-Terminal Kinase Cascades Is Involved in Part of the Neuronal Degeneration Induced by Trimethyltin in Cortical Neurons of Mice

The organotin trimethyltin (TMT) is known to cause neuronal degeneration in the central nervous system. A systemic injection of TMT produced neuronal damage in the cerebral frontal cortex of mice. To elucidate the mechanism(s) underlying the toxicity of TMT toward neurons, we prepared primary cultures of neurons from the cerebral cortex of mouse embryos for use in this study. Microscopic observations revealed that a continuous exposure to TMT produced neuronal damage with nuclear condensation in an incubation time–dependent manner up to 48 h. The neuronal damage induced by TMT was not blocked by N-methyl-D-aspartate receptor channel–blocker MK-801. The exposure to TMT produced an elevation of the phosphorylation level of c-Jun N-terminal kinase (JNK)^p46, but not JNK^p54, prior to neuronal death. Under the same conditions, a significant elevation was seen in the phosphorylation level of stress-activated protein kinase 1, which activates JNKs. Furthermore, TMT enhanced the expression and phosphorylation of c-Jun during a continuous exposure. The JNK inhibitor SP600125 was effective in significantly but only partially attenuating the TMT-induced nuclear condensation and accumulation of lactate dehydrogenase in the culture medium. Taken together, our data suggest that the neuronal damage induced by TMT was independent of excitotoxicity but that at least some of it was dependent on the JNK cascades in primary cultures of cortical neurons.     

MRI-pathological correlate of brain lesions in a necropsy case of HTLV-I associated myelopathy.

A postmortem case of HTLV-I associated myelopathy (HAM)/tropical spastic paraparesis (TSP) with a history of remission and exacerbation of neurological signs and symptoms, resembling those of multiple sclerosis is reported. MRI analysis revealed lesions in the periventricular white matter in addition to atrophy of the thoracic spinal cord, characteristic of HAM/TSP. The cerebral periventricular areas consisted of ill-defined paucity of myelin sheaths with astrocytic gliosis and hyaline thickening of blood vessels. The poorly demarcated white matter lesions found in both brain and spinal cord were different from plaques found in multiple sclerosis. It is suggested that, in some cases of HAM/TSP, inflammatory lesions that destroy myelin can involve not only the spinal cord but also the cerebral periventricular white matter.     

Objective evaluation of the visual field defects in a patient with cerebral infarction using multifocal VEPs]

PURPOSE: We investigated whether visual field defects can be objectively evaluated using multifocal visual evoked potentials (mVEP) in a patient with cerebral infarction in whom it is difficult to measure the visual field. METHODS: To determine normal waves in mVEP recording was performed using a VERIS Junior Science (Mayo, Aichi, Japan) in 20 healthy subjects (20 eyes), peak latency and amplitude were used for assessment. In a patient with cerebral infarction, mVEP were recorded, and compared with the lesion observed by computed tomography. RESULTS: In 20 healthy subjects, the waveforms in the nasal and temporal quadrants were very similar but the waveforms in the superior and inferior quadrants were mirror images. The mVEP in patient with cerebral infarction showed abnormal waves, corresponding to the visual field defects in the lesion observed by computed tomography. CONCLUSIONS: Objective evaluation of visual field defects using mVEP may be useful in patients with cerebral infarction in whom kinetic/static perimetry as a subjective examination is difficult.     

Rituximab was effective for acute disseminated encephalomyelitis followed by recurrent optic neuritis with anti-myelin oligodendrocyte glycoprotein antibodies

Background

The effect of rituximab on acute disseminated encephalomyelitis (ADEM) followed by recurrent optic neuritis (ON) is not yet known.

Full genomic analysis of a human group A rotavirus G9P[6] strain from Eastern India provides evidence for porcine-to-human interspecies transmission

Deduced amino acid sequence and phylogenetic analyses of a group A rotavirus G9P[6] strain (designated as mcs/13-07), detected from a 3-year-old child in Eastern India, revealed a VP8* closely related to porcine P[6] strains (P[6] sublineage 1D), and the VP7 clustered with G9 lineage-III strains. To our knowledge, this is the first report of human P[6] strain clustering in sublineage Id. Thus, to further characterize the evolutionary diversity of strain mcs/13-07, all gene segments were analyzed. VP6 and NSP4 exhibited genetic relatedness to Wa-like human subgroup II strains, while VP1-3, NSP1-3 and NSP5 were closely related to porcine strains. Based on the new classification system of rotaviruses, mcs/13-07 revealed a G9–P[6]–I1–R1–C1–M1–A8–N1–T1–E1–H1 genotype with close similarity to human Wa-like and porcine Gottfried strains. Therefore, considering the porcine-like or porcine origin of multiple gene segments, it might be tempting to assume that strain mcs/13-07 represents a rare instance of whole-virus transmission from pig to human, after which the virus evolved with time. Alternatively, it is possible that strain mcs/13-07 resulted from multiple reassortment events involving human subgroup II and porcine P[6] strains. Nevertheless, detection of strain mcs/13-07 provides further evidence for complex interspecies transmission events, which are frequent in developing countries.