Low response to a monovalent inactivated unadjuvanted influenza A (H1N1) pdm09 vaccine in pediatricians of a general hospital in Japan

Immunization of health care personnel (HCP) is critically important to reduce healthcare-associated influenza infections substantially. During 2009-2010, 74% of all HCP at Kitano Hospital, Osaka, Japan, including 94% of pediatricians, received the monovalent unadjuvanted influenza A (H1N1) pdm09 vaccine. We evaluated the vaccine's immunogenicity. Sixteen pediatricians received 15 μg hemagglutinin antigen subcutaneously. Antibody titer assays were conducted using hemagglutination-inhibition antibody assay on days 0 and 21, and at 5 mo after vaccination. Seroprotection rates, seroconversion rates, and geometric mean titer folds at 21 d were, respectively, 43.8%, 43.8%, and 5.4 in all subjects, 70.0%, 70.0%, and 8.0 in subjects aged 27-34 y, and 0.0%, 0.0%, and 8.0 in subjects aged ≥ 35 y. None of the latter group met the European Medicines Agency criteria. We hope to adopt intradermal routes and further the development of the influenza vaccine using new technology to improve immunogenicity in Japan.     

Ecology of hantaviruses in Mexico: Genetic identification of rodent host species and spillover infection

In our recent epidemiological survey conducted in Mexico for hantavirus infection, we identified three distinct viruses circulating in Mexican wild rodents, namely Montano virus (MTNV), Huitzilac virus (HUIV), and Carrizal virus (CARV). To gain a detailed understanding of hantavirus epidemiology and its associated hosts, 410 rodents were captured at eight collecting points in Morelos and Guerrero, Mexico, and examined for hantavirus seroprevalence, the presence of viral RNA, and rodent host species identification using cytochrome b gene sequences. Of the 32 species captured, seven species were positive for hantavirus: Peromyscus beatae (31/127; 24.4%), Reithrodontomys sumichrasti (6/15; 40%), Reithrodontomys megalotis (2/25; 8%), Peromyscus aztecus evides (1/1; 100%), Peromyscus megalops (1/41; 2.4%), Megadontomys thomasi (1/9; 11.1%), and Neotoma picta (1/6; 16.7%), with an overall prevalence of 10.5%; virus genome persisted in the majority of seropositive rodents. Nucleotide sequence and phylogenetic analysis showed that the viruses belonged mainly to the three lineages previously identified. The data showed that MTNV and CARV were primarily carried by P. beatae and R. sumichrasti, respectively. In addition, the data revealed an apparent complex interaction between hantaviruses and their hosts, suggesting active transmission and/or spillover infections within sympatric rodent species.     

Assessment of the otolith-ocular reflex using ocular vestibular evoked myogenic potentials in patients with episodic lateral tilt sensation

The otolith-ocular reflex in patients with episodic lateral tilt sensation without any other vestibular symptoms was assessed using ocular vestibular evoked myogenic potentials (oVEMP). Ten patients (6 men and 4 women, mean age=53.5) were enrolled. All patients had episodic lateral tilt sensation. Patients with a medical history of rotatory vertigo, loss of consciousness, head trauma, or symptoms or signs of central nervous dysfunction or proprioceptive dysfunction and those who had been definitely diagnosed with a disease that causes disequilibrium were excluded. All of the 10 patients had oVEMP tests and cervical VEMP (cVEMP) tests and underwent caloric tests. Eight of the 10 patients showed unilateral absence of oVEMP, one displayed a bilateral absence, and one displayed normal oVEMP. Concerning cVEMP, 4 patients showed a unilateral absence of cVEMP, one displayed unilaterally decreased responses and 5 displayed normal cVEMP. All patients showed normal bilateral caloric responses. The present study showed that patients with episodic lateral tilt sensation displayed abnormal otolith-ocular reflexes, as shown by their oVEMP, suggesting that these patients were suffering from utricular dysfunction.     

Directional remapping in tactile inter-finger apparent motion: a motion aftereffect study

Tactile motion provides critical information for perception and manipulation of objects in touch. Perceived directions of tactile motion are primarily defined in the environmental coordinate, which means they change drastically with body posture even when the same skin sensors are stimulated. Despite the ecological importance of this perceptual constancy, the sensory processing underlying tactile directional remapping remains poorly understood. The present study psychophysically investigated the mechanisms underlying directional remapping in human tactile motion processing by examining whether finger posture modulates the direction of the tactile motion aftereffect (MAE) induced by inter-finger apparent motions. We introduced conflicts in the adaptation direction between somatotopic and environmental spaces by having participants change their finger posture between adaptation and test phases. In a critical condition, they touched stimulators with crossed index and middle fingers during adaptation but with uncrossed fingers during tests. Since the adaptation effect was incongruent between the somatotopic and environmental spaces, the direction of the MAE reflects the coordinate of tactile motion processing. The results demonstrated that the tactile MAE was induced in accordance with the motion direction determined by the environmental rather than the somatotopic space. In addition, it was found that though the physical adaptation of the test fingers was not changed, the tactile MAE disappeared when the adaptation stimuli were vertically aligned or when subjective motion perception was suppressed during adaptation. We also found that the tactile MAE, measured with our procedure, did not transfer across different hands, which implies that the observed MAEs mainly reflect neural adaptations occurring within sensor-specific, tactile-specific processing. The present findings provide a novel behavioral method to analyze the neural representation for directional remapping of tactile motion within tactile sensory processing in the human brain.     

Human neural responses involved in spatial pooling of locally ambiguous motion signals

Early visual motion signals are local and one-dimensional (1-D). For specification of global two-dimensional (2-D) motion vectors, the visual system should appropriately integrate these signals across orientation and space. Previous neurophysiological studies have suggested that this integration process consists of two computational steps (estimation of local 2-D motion vectors, followed by their spatial pooling), both being identified in the area MT. Psychophysical findings, however, suggest that under certain stimulus conditions, the human visual system can also compute mathematically correct global motion vectors from direct pooling of spatially distributed 1-D motion signals. To study the neural mechanisms responsible for this novel 1-D motion pooling, we conducted human magnetoencephalography (MEG) and functional MRI experiments using a global motion stimulus comprising multiple moving Gabors (global-Gabor motion). In the first experiment, we measured MEG and blood oxygen level-dependent responses while changing motion coherence of global-Gabor motion. In the second experiment, we investigated cortical responses correlated with direction-selective adaptation to the global 2-D motion, not to local 1-D motions. We found that human MT complex (hMT+) responses show both coherence dependency and direction selectivity to global motion based on 1-D pooling. The results provide the first evidence that hMT+ is the locus of 1-D motion pooling, as well as that of conventional 2-D motion pooling.     

Prevalence of protozoa, viruses, coliphages and indicator bacteria in groundwater and river water in the Kathmandu Valley, Nepal

Limited information is available on the prevalence of waterborne pathogens in aquatic environments in developing countries. In this study, water samples were collected from nine shallow wells and a river in the Kathmandu Valley, Nepal, during the rainy season in 2009 and were subjected to detection of waterborne protozoa, viruses and coliphages using a recently developed method for simultaneous concentration of protozoa and viruses in water. Escherichia coli and total coliforms were also tested as indicator bacteria. At least one type of the five pathogens tested (Cryptosporidium, Giardia, human adenoviruses, and noroviruses of genogroups I and II) was detected in five groundwater samples (56%) (1000 ml each) from shallow wells. Compared with groundwater samples, the pathogens were more abundant in the river water sample (100 ml); the concentrations of Cryptosporidium and Giardia were 140 oocysts/l and 8500 cysts/l, respectively, and the mean threshold cycle (Ct) values in real-time RT-PCR were 34.3, 36.8 and 34.0 for human adenoviruses and noroviruses of genogroups I and II, respectively. Genotyping of F-RNA coliphages by real-time RT-PCR was successfully used to differentiate human and animal faecal contamination in the samples. Moreover, for the groundwater samples, protozoa and viruses were detected only in E. coli-positive samples, suggesting that E. coli may be an appropriate indicator of pathogen contamination of valley groundwater.     

Infectious mononucleosis with atypical manifestations accompanied by transient IgM antibody response for cytomegalovirus

Infectious mononucleosis (IM) is a clinical syndrome caused by primary infection with Epstein–Barr virus (EBV) that is common in adolescents. In adults, particularly in elderly people, the clinical picture of IM tends to be atypical, often leading to a diagnostic challenge. Diagnosis is also complicated because infection with EBV can induce the synthesis of cross-reacting immunoglobulin M antibodies for other herpesviruses. We report an unusual case of infectious mononucleosis in a 34-year-old immunocompetent adult. Epidemiological studies indicate that the average age of primary EBV infection in developed countries is increasing. IM with atypical presentation will be a diagnostic challenge in the future as the number of EBV-naïve adults increases.     

Identification and characterization of an oocyte factor required for development of porcine nuclear transfer embryos

Nuclear reprogramming of differentiated cells can be induced by oocyte factors. Despite numerous attempts, these factors and mechanisms responsible for successful reprogramming remain elusive. Here, we identify one such factor, necessary for the development of nuclear transfer embryos, using porcine oocyte extracts in which some reprogramming events are recapitulated. After incubating somatic nuclei in oocyte extracts from the metaphase II stage, the oocyte proteins that were specifically and abundantly incorporated into the nuclei were identified by mass spectrometry. Among 25 identified proteins, we especially focused on a multifunctional protein, DJ-1. DJ-1 is present at a high concentration in oocytes from the germinal vesicle stage until embryos at the four-cell stage. Inhibition of DJ-1 function compromises the development of nuclear transfer embryos but not that of fertilized embryos. Microarray analysis of nuclear transfer embryos in which DJ-1 function is inhibited shows perturbed expression of P53 pathway components. In addition, embryonic arrest of nuclear transfer embryos injected with anti-DJ-1 antibody is rescued by P53 inhibition. We conclude that DJ-1 is an oocyte factor that is required for development of nuclear transfer embryos. This study presents a means for identifying natural reprogramming factors in mammalian oocytes and a unique insight into the mechanisms underlying reprogramming by nuclear transfer.