WordNet

the 8th letter of the Roman alphabet (同)h

PrepTutorEJDIC

hydrogenの化学記号
鉛筆の硬度 / 《俗》heroin
high frequency 短波,高周波

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/07/07 22:01:56」(JST)

wiki en

Human foamy virus (HFV) is a retrovirus and specifically belongs to the genera Spumavirus. The spumaviruses are complex and significantly different from the other six genera of retroviruses in several ways. The foamy viruses derive their name from the characteristic ‘foamy’ appearance of the cytopathic effect (CPE) induced in the cells.^[1]

Discovery

The first description of foamy virus (FV) was in 1954. It was found as a contaminant in primary monkey kidney cultures. The first isolate of the “foamy viral agent” was in 1955. Not too long after this, it was isolated from a wide variety of New and Old World monkeys, cats, and cows. It was not until several years later that humans entered the scene. In 1971, a viral agent with FV-like characteristics was isolated from lymphoblastoid cells released from a human nasopharyngeal carcinoma (NPC) from a Kenyan patient.^[2] The agent was termed a human FV because of its origin, and named SFVcpz(hu) as the prototypic laboratory stain. The SFV came from its similarity to simian foamy virus (SFV). Not long after this, a group of researchers concluded that it was a distinct type of FV and most closely related to SFV types 6 and 7, both of which were isolated from chimpanzees. In another report, however, a different group of researchers claimed that SFVcpz(hu) was not a distinct type of FV but rather a variant strain of chimpanzee FV. The debate came to an end in 1994 when the virus was cloned and sequenced. The sequencing showed that there are 86-95% identical amino acids between the SFV and the one isolated from the Kenyan patient. In addition, phylogenetic analysis showed that the pol regions of the two genomes shared 89-92% of their nucleotides and 95-97% of the amino acids are identical between the human virus and various SFV strains. These results indicated that SFVcpz(hu) is likely a variant of SFV and not a unique isolate.^[1] When looking at the origin of the human FV, sequence comparisons showed that from four different species of chimpanzees, SFVcpz(hu) was most closely related to Pan troglodytes schweinfurthii. This species of chimpanzee has a natural habitat in Kenya and thus, the origin of the variant was most likely this species, and the virus was probably acquired as a zoonotic infection.^[2]

Life cycle

Most of the differences between the spumaviruses and the other retroviruses come from the life cycle. Some of the main differences are that FV buds from the endoplasmic reticulum instead of the plasma membrane; this difference gives FV a unique morphology. FV is characterized by an immature looking core with an electron lucent center with glycoprotein spikes on the surface.^[1] FV replication more closely resembles the Hepadnaviridae, which are another family of reverse transcriptase encoding viruses. Reverse transcription of the genome occurs at a later step in the replication cycle, which results in the infectious particles having DNA rather than RNA, this also leads to less integration in the host genome. The DNA found is linear and the length of the genome.^[3] The genome encodes the usual retroviral genes pol, gag, and env as well as two additional genes tas or bel-1 and bet. The role for bet is not quite clear, research has shown that it is dispensable for replication of the virus in tissue culture. The tas gene, however, is required for replication. It encodes a protein that functions in transactivating the long terminal repeat (LTR) promoter.^[4] FV has a second promoter, the internal promoter (IP) which is located in the env gene. The IP drives expression of the tas and bet genes. The IP is also unique in that the virus has the capacity to transcribe mRNAs from it; usually the complex retroviruses exclusively express transcripts from the LTR.^[5] The structural genes of FV are another one of its unique features. The Gag protein is not efficiently cleaved into the mature virus which lends to the immature morphology. The Pol precursor protein is only partially cleaved; the integrase domain is removed by viral protease. As in other retroviruses, the Env protein is cleaved into surface and transmembrane domains but the FV Env protein also contains an endoplasmic reticulum retention signal which is part of why the virus buds from the endoplasmic reticulum. Another area of difference between FV and other retroviruses is the possibility of recycling the core once the virus is in the cell.^[1]

Diseases

Persistence in the absence of disease, but in the presence of antibodies is a defining characteristic of FV infection. HFV has been isolated from patients with various neoplastic and degenerative diseases such as myasthenia gravis, multiple sclerosis, thyroiditis de Quervain, and Graves’ disease but the virus’ etiological role is still unclear.^[2] Recent studies indicate that it is not pathogenic in humans and experimentally infected animals.^[6]

Implications

If, in fact, HFV is not pathogenic in humans and is a retrovirus, it is an ideal vector for gene therapy. Another important feature of the virus is that the Gag, Pol, and Env proteins are synthesized independently; this is important because it means that each protein can be provided in trans on three different plasmids to create a stable packaging cell line. Having this would possibly reduce the need for a replication-competent helper virus.^[7] Other advantages are human to human transmission has never been reported, it has a safer spectrum of insertional mutagenesis than other retroviruses, and since there are two promoters in the genome, it may be possible to make a vector that expresses the foreign genes under the control of both promoters. A disadvantage of HFV as a gene therapy vector is that since it buds from an intracellular membrane (endoplasmic reticulum membrane); it results in low extracellular titers of the viral vector.^[6]

References

^ ^a ^b ^c ^d Meiering, Christopher D.; Maxine L. Linial (January 2001). "Historical Perspective of Foamy Virus Epidemiology and Infection". Clinical Microbiology Reviews (Clinical Microbiology Reviews) 14 (1): 165–176. doi:10.1128/CMR.14.1.165-176.2001. PMC 88968. PMID 11148008.
^ ^a ^b ^c "Human Foamy Virus". Stanford University.
^ Moebes, Astrid; Jorg Enssle; Paul D. Bieniasz; Martin Heinkelein; Dirk Lindemann; Michael Bock; Myra O. McClure; Axel Rethwilm (October 1997). "Human Foamy Virus Reverse Transcription That Occurs late in the Viral Replication Cycle". Journal of Virology. pp. 7305–7311.
^ Yu, Shuyuarn F.; Mark D. Sullivan; Maxine L Linial (February 1999). "Evidence that the Human Foamy Virus Genome is DNA". Journal of Virology. pp. 1565–1572.
^ Lochelt, Martin; Walter Muranyi; Rolf M. Flugel (August 1993). "Human Foamy Virus genome possesses an internal, Bel-1-dependent and functional promoter". Proceedings of the National Academy of Sciences of the United States of America. pp. 7317–7321.
^ ^a ^b Liu, Wanhong; Zhongchun Liu; Xiongbin Cao; Ahijan Cao; Lu Xue; Fan Zhu; Xiaohua He; Wenxin LI (October 2007). "Recombinant Human Foamy Virus, a Novel Vector for Neurological Disorders Gene Therapy, Drives Production of GAD in Cultured Astrocytes". Molecular Therapy. pp. 1834–1841.
^ Hill, Claire L.; Paul D. Bieniasz; Myra O. McClure (1999). "Properties of human foamy virus relevant to its development as a vector for gene therapy". Journal of General Virology. pp. 2003–2009.

External links

Human foamy virus at the US National Library of Medicine Medical Subject Headings (MeSH)

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 成人における高頻度人工呼吸 high frequency ventilation in adults
2. 新生児における機械的人工換気 mechanical ventilation in neonates
3. 機械的人工換気のモード modes of mechanical ventilation
4. 急性呼吸窮迫症候群における機械的人工換気 mechanical ventilation in acute respiratory distress syndrome
5. 新生児における先天性横隔膜ヘルニア congenital diaphragmatic hernia in the neonate

English Journal

High frequency jet ventilation versus high frequency oscillatory ventilation for pulmonary dysfunction in preterm infants.

Ethawi YH1, Abou Mehrem A, Minski J, Ruth CA, Davis PG.
The Cochrane database of systematic reviews.Cochrane Database Syst Rev.2016 May 6;5:CD010548. [Epub ahead of print]
BACKGROUND: Respiratory distress syndrome (RDS) is considered one of the major contributors to severe pulmonary dysfunction and consequent death in preterm infants. Despite widespread improvements in care, including increased utilization of antenatal steroids, use of surfactant replacement therapy,
PMID 27149997

Diagnostic accuracy of capnography during high-frequency ventilation in neonatal intensive care units.

Kugelman A1,2, Bromiker R3, Riskin A1, Shoris I1, Ronen M4, Qumqam N3, Bader D1, Golan A5.
Pediatric pulmonology.Pediatr Pulmonol.2016 May;51(5):510-6. doi: 10.1002/ppul.23319. Epub 2015 Sep 30.
BACKGROUND AND OBJECTIVE: High-frequency ventilation (HFV) is a powerful tool for CO2 elimination, and thus requires careful monitoring of CO2 . Our aim was to assess the diagnostic accuracy (correlation, agreement, and trending) of continuous distal capnography (dCap) with PaCO2 in infants ventilat
PMID 26422449

FGF21 therapy attenuates left ventricular dysfunction and metabolic disturbance by improving FGF21 sensitivity, cardiac mitochondrial redox homeostasis and structural changes in pre-diabetic rats.

Tanajak P1,2,3, Sa-Nguanmoo P1,2,3, Wang X4, Liang G4, Li X4, Jiang C4, Chattipakorn SC1,3,5, Chattipakorn N1,2,3.
Acta physiologica (Oxford, England).Acta Physiol (Oxf).2016 Apr 27. doi: 10.1111/apha.12698. [Epub ahead of print]
AIMS: Fibroblast growth factor 21 (FGF21) acts as a metabolic regulator and exerts cardioprotective effects. However, the effects of long term FGF21 administration on the heart under the FGF21 resistant condition in obese-insulin resistant rats have not been investigated. We hypothesized that long t
PMID 27119620

Japanese Journal

HfV_2の強磁場と高圧下における磁気的，熱伝的及び構造的特性

小山佳一,五十嵐利行,渡辺和雄,コヤマケイイチ,イガラシトシユキ,ワタナベカズオ,KOYAMA Keiichi,IGARASHI Toshiyuki,WATANABE Kazuo
鹿児島大学理学部紀要=Reports of the Faculty of Science, Kagoshima University 47, 13-19, 2014-12-30
… Magnetic susceptibility χ, electrical resistivity ρ, thermoelectric power (Seebeck coefficient) S and X-raydiffraction (XRD) measurements of Laves phase compound HfV_2 were measured in the temperature T range from 4.2 to300 K under magnetic fields B up to 17 T and pressures P up to 1.2 GPa. …
NAID 120005575088

心電図同期心筋SPECT壁運動解析ソフトウエアHFVによる心容積算出の精度について

長池大和,新里光太郎,木村元政 [他]
新潟核医学懇話会記録集 40, 1-6, 2013-04-20
NAID 40020197990

Hollow Fiber Vitrification : A Novel Method for Vitrifying Multiple Embryos in a Single Device

MATSUNARI Hitomi,MAEHARA Miki,NAKANO Kazuaki [他],IKEZAWA Yuka,HAGIWARA Yui,SASAYAMA Norihisa,SHIRASU Akio,OHTA Hisayoshi,TAKAHASHI Masashi,NAGASHIMA Hiroshi
The Journal of reproduction and development 58(5), 599-608, 2012-10-01
… Survival rates of up to 100% were obtained for mouse embryos vitrified in the presence of 15% DMSO, 15% ethylene glycol and 0.5 M sucrose using the hollow fiber vitrification (HFV) method, regardless of the developmental stage of the embryos (1-cell, 2-cell, morula or blastocyst; … The HFV method was also proven to be effective for vitrifying porcine in vitro- and in vivo-derived embryos that are known to be highly cryosensitive. …
NAID 10031123306

Related Pictures

★リンクテーブル★

リンク元	「human foamy virus」「高頻度人工換気法」「high frequency ventilation」「ヒト泡沫状ウイルス」
関連記事	「HF」「H」

「human foamy virus」

Human foamy virus
Virus classification
Group:	Group VI (ssRNA-RT)
Family:	Retroviridae
Subfamily:	Spumaretrovirinae
Genus:	Spumavirus
Species:	Simian foamy virus
Serotype
	Human foamy virus