质膜脂微区--一种新发现的膜局限性结构域

脂微区为近年发现的广泛存在于质膜,主要由糖鞘脂、鞘磷脂、胆固醇及多GPI锚联蛋白组成的局限性结构域.该区具特殊的化学组成及特性,且富集许多重要的信号传递分子,在介导细胞信号传递过程中起重要作用.此外,脂微区与膜微囊之间既有区别又有联系.     

Developmental topographical disorientation: a newly discovered cognitive disorder

A variety of lesions in different cerebral regions may affect the human ability to orient in the environment, resulting in ‘topographical disorientation’. In a recent study, we documented the first case of Developmental Topographical Disorientation (DTD), in a person with a life-long inability to orient despite otherwise well-preserved cognitive functions, and in the absence of a cerebral injury/malformation or other neurological condition. This selective topographical disorientation was due to her inability to form a ‘cognitive map’, a mental representation of the environment, which in turn impaired her ability to orient in both familiar and unfamiliar surroundings. Here, we describe 120 new cases of DTD recruited via the internet and assessed with an online battery testing their cognitive and orientation skills. We found that people with DTD differ from matched (age, gender and education) healthy controls only in those skills confined to the orientation/navigation domain, among which the ability to form a cognitive map was the most significant factor that distinguished a person affected by DTD from control subjects.     

Morphological evidence for newly discovered double projection spinal neurons

A novel population of spinal neurons is shown to terminate in two nuclei: the lateral cervical nucleus and the dorsal column nuclei. Nuclear yellow and Fast blue injected respectively into these nuclei are retrogradely transported to common neurons in the lumbosacral dorsal horn. The bifurcation of these neurons' axons appears to occur at the cervico-thoracic junction. These results indicate that some dorsal horn neurons transmit sensory information to two distinct nuclei. The two projections and their branching points may play a special role in neuronal communication.     

GLUT1: a newly discovered immunohistochemical marker for juvenile hemangiomas

Juvenile hemangiomas are common, benign vascular tumors of infancy. These lesions enlarge rapidly through cellular hyperplasia during the first year of life and then involute over several years. Distinctive histopathologic features of hemangiomas diminish during this evolution, and differentiation from vascular malformations becomes increasingly difficult. This distinction has important therapeutic implications, as juvenile hemangiomas differ from malformations in natural history and in potential for recurrence. We report here that high endothelial immunoreactivity for the erythrocyte-type glucose transporter protein GLUT1 is a specific feature of juvenile hemangiomas during all phases of these lesions. In a retrospective study, we found intense endothelial GLUT1 immunoreactivity, involving more than 50% of lesional microvessels, in 97% (139 of 143) of juvenile hemangiomas from patients aged 1 month to 11 years. No endothelial GLUT1 immunoreactivity was found in any of 66 vascular malformations (17 arteriovenous, 33 venous, 11 lymphatic, and 5 port-wine) from patients aged 5 days to 75 years, or in any of 20 pyogenic granulomas or 7 granulation tissue specimens. Abundant Ki-67 positivity in these latter lesions established that GLUT1 expression does not simply reflect mitotically active endothelium. Focal GLUT1 immunoreactivity was found in 3 of 12 angiosarcomas, but not in any of 5 hemangioendotheliomas (epithelioid or infantile kaposiform). These findings establish GLUT1 immunoreactivity as a highly selective and diagnostically useful marker for juvenile hemangiomas. Because high levels of endothelial GLUT1 expression in normal tissue are restricted to microvessels with blood-tissue barrier function, these findings also have implications for the molecular and developmental pathogenic mechanisms of juvenile hemangiomas.     

Saliviruses—the first knowledge about a newly discovered human picornavirus

The salivirus, first discovered in the year 2009, is a member of the large and growing family Picornaviridae. At present, the genus Salivirus contains 1 species Salivirus A and 2 genotypes, Salivirus A1 and Salivirus A2. Salivirus has been identified in humans and chimpanzees and may cause acute gastroenteritis in humans, having been detected in 0% to 8.7% of fecal samples collected from gastroenteritis in different human populations. Salivirus is ubiquitous in wastewater of human origin and river water specimens worldwide and represents a potential indicator human RNA virus for monitoring of environmental samples. This review summarizes the current knowledge on saliviruses including discovery, taxonomy, genome structure, and genetic diversity; covers all aspects of infection including epidemiology, molecular epidemiology, clinical feature, host species, environmental characteristics, and laboratory diagnosis; and gives a summary of possible future perspectives.     

A newly discovered Fc receptor that explains IgG-isotype disparities in effector responses

The known IgG FcRs primarily mediate inflammation by interacting with IgG1, even though IgG2 isotypes tend to be more pathogenic. A novel FcgammaR that binds IgG2 but not IgG1 has just been identified, potentially explaining differences in biological activity that are seen with various IgG isotypes.     

Serology and cytokine profiles in patients infected with the newly discovered Bundibugyo ebolavirus

A new species of Ebolavirus, Bundibugyo ebolavirus, was discovered in an outbreak in western Uganda in November 2007. To study the correlation between fatal infection and immune response in Bundibugyo ebolavirus infection, viral antigen, antibodies, and 17 soluble factors important for innate immunity were examined in 44 patient samples. Using Luminex assays, we found that fatal infection was associated with high levels of viral antigen, low levels of pro-inflammatory cytokines, such as IL-1α, IL-1β, IL-6, TNF-α, and high levels of immunosuppressor cytokines like IL-10. Also, acute infected patients died in spite of generating high levels of antibodies against the virus. Thus, our results imply that disease severity in these patients is not due to the multi-organ failure and septic shock caused by a flood of inflammatory cytokines, as seen in infections with other Ebolavirus species.     

Reovirus genomes from plant-feeding insects represent a newly discovered lineage within the family Reoviridae

A complex set of double-stranded RNAs (dsRNAs) was isolated from threecornered alfalfa hopper (Spissistilus festinus), a plant-feeding hemipteran pest. A subset of these dsRNAs constitute the genome of a new reovirus, provisionally designated Spissistilus festinus reovirus (SpFRV). SpFRV was present in threecornered alfalfa hopper populations in the San Joaquin Valley of California, with incidence ranging from 10% to 60% in 24 of 25 sample sets analyzed. The 10 dsRNA segments of SpFRV were completely sequenced and shown to share conserved terminal sequences (5′-AGAGA and CGAUGUUGU-3′) of the positive-sense strand that are distinct from known species of the family Reoviridae. Comparisons of the RNA directed RNA polymerase (RdRp) indicated SpFRV is most closely related (39.1% amino acid identity) to another new reovirus infecting the angulate leafhopper (Acinopterus angulatus) and provisionally designated Acinopterus angulatus reovirus (AcARV). The RdRp of both viruses was distantly related to Raspberry latent virus RdRp at 27.0% (SpFRV) and 30.0% (AcARV) or Rice ragged stunt virus RdRp at 26.2% (SpFRV) and 29.0% (AcARV) amino acid identity. RdRp phylogeny confirmed that SpFRV and AcARV are sister taxa sharing a most recent common ancestor. SpFRV segment 6 encodes a protein containing two NTP binding motifs that are conserved in homologs of reoviruses in the subfamily Spinareovirinae. The protein encoded by SpFRV segment 4 was identified as a guanylyltransferase homolog. SpFRV segments 1, 3, and 10 encode homologs of reovirus structural proteins. No homologs were identified for proteins encoded by SpFRV segments 5, 7, 8, and 9. Collectively, the low level of sequence identity with other reoviruses, similar segment terminal sequences, RdRp phylogeny, and host taxa indicate that SpFRV and AcARV may be considered members of a proposed new genus of the family Reoviridae (subfamily Spinareovirinae), with SpFRV assigned as the type species.     

Genome characterisation of the newly discovered avian influenza A H5N7 virus subtype combination

Summary. In Denmark, in 2003, a previously unknown subtype combination of avian influenza A virus, H5N7 (A/Mallard/Denmark/64650/03), was isolated from a flock of 12,000 mallards. The H5N7 subtype combination might be a reassortant between recent European avian influenza A H5, H7, and a third subtype, possibly an H6. The haemagglutinin and the acidic polymerase genes of the virus were closely related to a low-pathogenic Danish H5N2 virus A/Duck/Denmark/65041/04 (H5N2). The neuraminidase gene and the non-structural gene were most similar to the highly pathogenic A/Chicken/Netherlands/1/03 (H7N7) and the human-fatal A/Netherlands/219/03 (H7N7), respectively. The basic polymerase 1 and 2 genes were phylogenetically equidistant to both A/Duck/Denmark/65047/04 (H5N2) and A/Chicken/Netherlands/1/03 (H7N7). The nucleoprotein and matrix gene had highest nucleotide sequence similarity to the H6 subtypes A/Duck/Hong Kong/3096/99 (H6N2) and A/WDk/ST/1737/2000 (H6N8), respectively. All genes of the H5N7 strain were of avian origin, and no further evidence of pathogenicity to humans has been found.     

Characterization of a newly discovered Mu-like bacteriophage, RcapMu, in Rhodobacter capsulatus strain SB1003

The α-proteobacterium Rhodobacter capsulatus is a model organism for the study of bacterial photosynthesis and the bacteriophage-like gene transfer agent. Characterization of phages that infect Rhodobacter is extremely rare, and scarce for the α-proteobacteria in general. Here, we describe the discovery of the only functional Mu-like transposing phage to have been identified in the α-proteobacteria, RcapMu, resident in the genome-sequenced R. capsulatus SB1003 strain. RcapMu packages ~ 42 kb of total DNA, including < 3 kb of host DNA with no conserved motifs, indicative of replicative transposition with little insertion site preference. The phage genome contains 58 ORFs with comparable organization to known transposable phages. Shotgun proteomics of purified RcapMu particles detected all proteins with predicted structural functions as well as seven hypothetical proteins. Overall, comparison of RcapMu to enterobacteria phage Mu and other Mu-like phages revealed only regional homology to these phages, providing further evidence for the promiscuous, modular nature of bacteriophage evolution.     

Characterisation of a newly identified human rhinovirus, HRV-QPM, discovered in infants with bronchiolitis.

BACKGROUND: Human rhinoviruses (HRVs) are some of the earliest identified and most commonly detected viruses associated with acute respiratory tract infections (ARTIs) and yet the molecular epidemiology and genomic variation of individual serotypes remains undefined. OBJECTIVES: To molecularly characterise a novel HRV and determine its prevalence and clinical impact on a predominantly paediatric population. STUDY DESIGN: Nucleotide sequencing was employed to determine the complete HRV-QPM coding sequence. Two novel real-time RT-PCR diagnostic assays were designed and employed to retrospectively screen a well-defined population of 1244 specimen extracts to identify the prevalence of HRV-QPM during 2003. RESULTS: Phylogenetic studies of complete coding sequences defined HRV-QPM as a novel member the genus Rhinovirus residing within the previously described HRV-A2 sub-lineage. Investigation of the relatively short VP1 sequence suggest that the virus is resistant to Pleconaril, setting it apart from the HRV A species. Sixteen additional HRV-QPM strains were detected (1.4% of specimens) often as the sole micro-organism present among infants with suspected bronchiolitis. HRV-QPM was also detected in Europe during 2006, and a closely related virus circulated in the United States during 2004. CONCLUSIONS: We present the molecular characterisation and preliminary clinical impact of a newly identified HRV along with sequences representing additional new HRVs.     

Seroprevalence of Human Malawi Polyomavirus

The seroprevalence of the recently discovered human Malawi polyomavirus (MWPyV) was determined by virus-like particle-based enzyme-linked immunosorbent assay (ELISA) in age-stratified Italian subjects. The findings indicated that MWPyV infection occurs early in life, and seroprevalence was shown to reach 42% in adulthood.     

Polyomavirus infection and urothelial carcinoma

Introduction: Polyomavirus infections are common in the general (adult) population with a reported prevalence of more than 80%. Polyomavirus can infect urothelial carcinoma and change the morphology of these malignant cells, as is shown in this paper. Material and Methods: An eighty year old Hispanic male was referred to the urology clinic for diagnosis and treatment. The submitted voided urine sample was concentrated, processed, and a SurePath preparation was made. Results and Discussion: The Papanicolaou‐stained slides contained single cells with very large hyperchromatic nuclei with a glassy appearance in addition to atypical neoplastic cells. The single cells with enlarged nuclei proved to stain positive for Simian virus 40 (SV40) antigen. The nuclei of these cells were 2 to 4 times larger than that of the surrounding noninfected atypical cells. These findings were confirmed on histologic sections prepared from tissue biopsy. Conclusion: In conclusion we report that it is difficult to distinguish benign polyomavirus infected cells from their malignant counterparts in cytology but not in histology. Diagn. Cytopathol. 2010. © 2010 Wiley‐Liss, Inc.