reticulocyte count

WordNet

1. name or recite the numbers in ascending order; "The toddler could count to 100"
2. the total number counted; "a blood count"
3. the act of counting; reciting numbers in ascending order; "the counting continued for several hours" (同)counting, numeration, enumeration, reckoning, tally
4. a nobleman (in various countries) having rank equal to a British earl
5. have faith or confidence in; "you can count on me to help you any time"; "Look to your friends for support"; "You can bet on that!"; "Depend on your family in times of crisis" (同)bet, depend, look, calculate, reckon
6. have weight; have import, carry weight; "It does not matter much" (同)matter, weigh
7. put into a group; "The academy counts several Nobel Prize winners among its members" (同)number
8. determine the number or amount of; "Can you count the books on your shelf?"; "Count your change" (同)number, enumerate, numerate
9. have a certain value or carry a certain weight; "each answer counts as three points"
10. include as if by counting; "I can count my colleagues in the opposition"
11. an immature red blood cell containing a network of filaments or granules

PrepTutorEJDIC

1. (一つ一つ順に)〈数〉'を'『数える』,〈物〉'を'数え上げる《+『up』+『名,』+『名』+『up』》 / …'を'『勘定に入れる』,含める(include) / …'を'『思う』,みなす(consider) / 数を数える,計算する《+『up』》 / 数にはいる,数に含まれる / 価値がある,重大である / 〈C〉〈U〉『数えること』,『計算』 / 〈U〉総数,総計 / 〈U〉(起訴状の)訴因 / 《the~》(ボクシングで)カウント(選手がノックダウンされたときレフリーが1から10まで数えること) / 〈C〉(野救で打者の)ボールカウント / 〈U〉《話》考慮,注目(account)
2. (英国以外の)伯爵

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/10/28 20:39:48」(JST)

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Not to be confused with reticular cell.

Reticulocyte
Reticulocytes
Erythrocytes (mature cells)
Details
Identifiers
Latin	reticulocytus
Code	TH H2.00.04.1.01007
Anatomical terminology [edit on Wikidata]

Reticulocytes are immature red blood cells, typically composing about 1% of the red blood cells in the human body. In the process of erythropoiesis (red blood cell formation), reticulocytes develop and mature in the bone marrow and then circulate for about a day in the blood stream before developing into mature red blood cells. Like mature red blood cells, in mammals reticulocytes do not have a cell nucleus. They are called reticulocytes because of a reticular (mesh-like) network of ribosomal RNA that becomes visible under a microscope with certain stains such as new methylene blue.

Reticulocytes as a clinical indicator

To accurately measure reticulocyte counts, automated counters use a combination of laser excitation, detectors and a fluorescent dye that marks RNA and DNA (such as titan yellow or polymethine). Reticulocytes can be distinguished from other circulating cells because they emit a signal that is neither strong (like lymphocytes) nor weak (like red blood cells).

Reticulocytes appear slightly bluer than other red cells when looked at with the normal Romanowsky stain. Reticulocytes are also relatively large, a characteristic that is described by the mean corpuscular volume.

Supravital stain of a smear of human blood from a patient with hemolytic anemia. The reticulocytes are the cells with the dark blue dots and curved linear structures (reticulum) in the cytoplasm.

The normal fraction of reticulocytes in the blood depends on the clinical situation but is usually 0.5% to 2.5% in adults and 2% to 6% in infants. A reticulocyte percentage that is higher than "normal" can be a sign of anemia, but this depends on the health of a person's bone marrow. Calculating the reticulocyte production index is an important step in understanding whether or not the reticulocyte count is appropriate to the situation. This is often a more important question than whether the percentage is in the normal range; for instance, if someone is anemic but has a reticulocyte percentage of only 1%, the bone marrow is likely not producing new blood cells at a rate that will correct the anemia.

The number of reticulocytes is a good indicator of bone marrow activity because it represents recent production and allows for the determination of reticulocyte count and the reticulocyte production index. These values can be used to determine whether a production problem is contributing to the anemia and can also be used to monitor the progress of treatment for anemia.

When there is an increased production of red blood cells to overcome chronic or severe loss of mature red blood cells, such as in a haemolytic anemia, there is often a markedly high number and percentage of reticulocytes. A very high number of reticulocytes in the blood can be described as reticulocytosis.

Abnormally low numbers of reticulocytes can be attributed to chemotherapy, aplastic anemia, pernicious anemia, bone marrow malignancies, problems of erythropoietin production, various vitamin or mineral deficiencies (iron, vitamin B₁₂, folic acid), disease states (anemia of chronic disease) and other causes of anemia due to poor RBC production.

Stages of development

The development begins with the extrusion of the normoblast nucleus and ends when the reticulocyte has lost its organelles.

Research

Reticulocytes are a valuable tool for biologists who study protein translation. Reticulocytes are unusual among cells in that they contain all of the machinery necessary to translate proteins but lack a nucleus. Since a cell's nucleus contains many components that make studying translation difficult, these cells are quite useful. Scientists can collect reticulocytes from animals such as rabbits and extract the mRNA and translation enzymes to study protein translation in a cell-free, in vitro system, allowing greater control over the environment in which proteins are being synthesized.

References

External links

• For more information on Reticulocyte Count

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. 成人における溶血性貧血の診断へのアプローチ approach to the diagnosis of hemolytic anemia in the adult
• 2. 貧血を有する成人患者に対するアプローチ approach to the adult patient with anemia
• 3. 貧血を有する小児に対するアプローチ approach to the child with anemia
• 4. 赤血球産生低下による貧血 anemias due to decreased red cell production
• 5. 大赤血球症 macrocytosis

English Journal

• ICSH guidelines for the laboratory diagnosis of nonimmune hereditary red cell membrane disorders.

• King MJ1, Garçon L, Hoyer JD, Iolascon A, Picard V, Stewart G, Bianchi P, Lee SH, Zanella A; International Council for Standardization in Haematology.
• International journal of laboratory hematology.Int J Lab Hematol.2015 Jun;37(3):304-25. doi: 10.1111/ijlh.12335. Epub 2015 Mar 18.
• INTRODUCTION: Hereditary spherocytosis (HS), hereditary elliptocytosis (HE), and hereditary stomatocytosis (HSt) are inherited red cell disorders caused by defects in various membrane proteins. The heterogeneous clinical presentation, biochemical and genetic abnormalities in HS and HE have been well
• PMID 25790109

• Altitude Exposure at 1800 m Increases Haemoglobin Mass in Distance Runners.

• Garvican-Lewis LA1, Halliday I2, Abbiss CR3, Saunders PU4, Gore CJ5.
• Journal of sports science & medicine.J Sports Sci Med.2015 May 8;14(2):413-7. eCollection 2015.
• The influence of low natural altitudes (< 2000 m) on erythropoietic adaptation is currently unclear, with current recommendations indicating that such low altitudes may be insufficient to stimulate significant increases in haemoglobin mass (Hbmass). As such, the purpose of this study was to deter
• PMID 25983592

Japanese Journal

• Erythroid Recovery Affects Tacrolimus Levels after Engraftment during Stem Cell Transplantation

• Fukuoka Noriyasu,Imataki Osamu,Tanaka Hiroaki,Tani Kumiko,Ohnishi Hiroaki,Houchi Hitoshi
• Biological and Pharmaceutical Bulletin 35(10), 1648-1654, 2012
• … Multivariate analysis revealed that the reticulocyte (RET) level (×103 count/µL) was the sole parameter influencing this ratio, and both parameters were expressed as: Variation ratio=0.004×RET+1.0. …
• NAID 130001872352

• EPO responsiveness in hemodialysis patients with excessive ferritin

• 堀江 正宣,長谷川 栄三,小塚 信,菰田 茂樹,森口 佳之,長谷川 正広,山羽 正義,蓑島 謙一,南舘 謙,河合 篤史,永井 真吾,服部 愼一
• 日本透析医学会雑誌 45(2), 163-169, 2011
• … Although the reticulocyte count tended to be higher in the Hb-Low group compared to Hb-High group, this led to no improvement in Hb (Hb: 9.4±0.6 vs. 10.5±0.5g/dL, p<0.001; …
• NAID 130002145647

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「count」

「count」

　　[★]

• n.

• 数、数値

• v.

• 数える、カウントする

関

number、numeral