w*******7 发帖数: 412 | 1 otherwise health young pregnant women is found to have macrocytic anemia in
her 2nd trimeter. Has been taking prenatal vitamin through the pregancy (
including 1mg folate acid) and extra oral VB12 3000mcg daily for 2 months.
Hb is still around 11g/dL and MCV around 102. serum VB12 level is 718pg/mL (
211~911).
Methylmalonic acid serum level is 113nmol/L (87~318), Homocysteine level is
6.6(5.5~15).
patient's 36 weeks prenatal ultrasound found fetal weight 5.5lbs(25%), while
AC(abdominal circumsta... 阅读全帖 |
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c**********m 发帖数: 2088 | 2 An underactive thyroid gland can lead to macrocytic anemia. 近10个孕妇中有1
个患甲减。
甲状腺功能减退简称甲减常伴有贫血,其发生率约占甲减患者的1/3—1/2,多数为轻、
中度正常血红蛋白或低血红蛋白小红细胞型贫血,少数为恶性贫血(大细胞性贫血)。那
么甲减性贫血的发病机制是什么呢?
(1)甲状腺激素有促进红细胞生成的功能,当甲减时甲状腺分泌减少,骨髓因缺乏
甲状腺激素而特异性受抑,呈增生不良,减少了红细胞生成素的促进物质之一,使红细
胞生成素减少而致贫血。
(2)甲减病人厌食,胃酸缺乏,约半数病例可继发有吸收减少,蛋白质与维生素B12吸收
减少,以及其它营养物质摄入减少,引起营养不良性贫血,①甲减时血容量减少,约有
32%—84%的病例血红蛋白可低至80—90g/L;以及月经过多大量失血也可导致贫血;
②某些病人因胃内因子缺乏使维生素B12吸收减少,造成大细胞性贫血,另甲减病人中
抗甲状腺抗体检出率相当高,因此认为发生大细胞性贫血可能与自身免疫对胃粘膜的损
害有关。 |
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e***5 发帖数: 106 | 3 对对,忘了成熟RBC没有核和DNA,狂汗.....当然Reticulocytes是有的,所以在产生
macrocytic anemia的过程中还是不能排除DNA因素?
“LZ列的那些药物是通过影响DNA合成(形成megaloblast)而导致Megaloblastic
macrocytic anemia的”,事实上FA中这些药物是被列在导致NonMegaloblastic
macrocytic anemia的,我们在这里讨论半天就是为什么这些药物会引起
NonMegaloblastic macrocytic anemia而不是Megaloblastic macrocytic anemia。我
总结一下,原因可能
是这样的:就像junhe说的,这些药物一般不会长期使用到产生骨髓抑制的程度,
虽然理论上是会产生Megaloblastic macrocytic anemia的,但临床上一般因产生
NonMegaloblastic macrocytic anemia(至于为什么会产生macrocytic anemia,我们
还没讨论出个结果来,但无非是两个因素,要么是直接影响细胞形态,要么是通... 阅读全帖 |
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x******a 发帖数: 195 | 5 I don't think FA is correct on this.
5-FU等影响DNA合成的药物,理论上都能够导致megaloblastic macrocytic anemia。但
是临床上可能很罕见。不是因为骨髓抑制不够严重,恰恰相反,是产生了严重的骨髓抑
制:The cells simply die!这些化疗药会kill blasts,所以三系细胞都会急性下降
。要产生megaloblastic macrocytic anemia,这些megaloblasts必须survive,形成
macrocytic RBC。可以想象,如果长期服用极低剂量的5-FU,就会产生megaloblastic
macrocytic anemia。
5-FU不会通过影响细胞膜或者reticulocyte而引起nonmegaloblastic macrocytic
anemia。这些化疗药的靶点就是DNA而不是细胞膜,而且reticulocyte也没有DNA。 |
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j***e 发帖数: 62 | 6 1:Megaloblastic macrocytic anemia 是VitB12 或者叶酸缺乏引起。
2:Nonmegaloblastic macrocytic anemia 是由其他非VitB12 叶酸缺乏引起的大细胞
性贫血,如酒精性肝病。与前者区别:Macrocytes are round ,Hypersegmented
neutrophils are not present。Alcohol是此种类型最常见的原因。 |
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x******a 发帖数: 195 | 7 理论上,LZ说的那些影响DNA synthesis的药都会导致Megaloblastic macrocytic
anemia。只不过叶酸和B12缺乏是最常见的原因。DNA合成障碍会导致细胞核成熟受阻,
但同时RNA、细胞浆物质的合成会继续,细胞变大,形成megaloblast。这应该包括所有
lineage的blast。Hypersegmented neutrophils by definition并不是megaloblast,
跟巨大的RBC一样只是megaloblast的产物。
Nonmegaloblastic macrocytic anemia不是DNA合成受阻引起的,没有megaloblast形成
。通常由酒精(直接毒性)、红细胞膜障碍(肝病)、reticulocytosis(hemolysis)
等导致。如果酒精引起叶酸缺乏,则又会导致Megaloblastic macrocytic anemia。 |
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w*******7 发帖数: 412 | 8 哎,你们越说我越害怕了. 我不喝酒,连bubble tea都不喝.本来天天点外卖的人才怀孕
后开始自己买菜做饭.感觉除了上班其余时间都用来吃饭睡觉了
尤其周末花好多时间在吃上.
我第一次发现macrocytic anemia的时候就要求IM injection了,OB不同意连口服都不给
开,我只好自己去pharmacy买oral supplement. 没想到吃了2个月查了3次还是
macrocytic anemia,还是不同的lab查的.但是我半年前的一次CBC确实是WNL的.
我除了morning sickness which comes with pregnancy外没有其他GI symptoms, 没有hypothyroidism symptoms, Live function normal, no past medical history,no family history, not on any other meds except prenatal vitamin(contain 1mg folic acid per tablet) and oral V12. 想不出wh... 阅读全帖 |
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w*******7 发帖数: 412 | 9 都2个月了,从发现的时候就和OB说了,OB 自己给开的检查,有macrocytic anemia,不是
我提醒她都没意识到指标异常.后来问她要不要补充v B12 and folic acid,她说不用,
吃prenatal vitamin is enough.可是我本来就每天都吃prenatal vitamin的,想想自己
专门又去买了额外的B12 and folic acid每天吃,过了2个月了还是没有改善,MCV还是
102.今天门诊的internist 打我电话让我去查VB 12 level and methylmalonic acid
level. 说如果低去用IM injection of VB12.
我现在很不高兴,觉得我的OB怎么没有on top of everythings 呢? 前不久竟然还让我
用了categorical C 的pain killer, while there's categorical B pain killer
exist, 如果不是我说她竟然都不知道哪个药是categorical B or C! 现在她忽然去
vacation了,也没有和我说,... 阅读全帖 |
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e***5 发帖数: 106 | 10 多谢君荷,我对关于magloblastic and macrocytic一直都没搞清楚过,再请教一下,
看我理解是否正确:1,magloblastic是专对于有骨髓抑制而言的,正因为骨髓抑制,
才会出现multi-lobulated neutrophil(发育不全?)。5FU若也引起骨髓抑制,那也
会引起magloblastic,所以这不是绝对的,当然真实情况可能发生几率较小。2,相对
于骨髓抑制,红细胞对DNA损伤比较敏感(可能是新成代谢比别的血细胞快?),所以有
些药物可引起macrocytic, 却还
没到magloblastic的程度。 |
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e***5 发帖数: 106 | 11 请教xingqiba,macrocytic的机制是什么,为什么MCV会变大?我的理解一个因素是非
DNA因素如酒精(直接毒性)、红细胞膜障碍等,另外一因素是DNA因素,要不然FA也不
会把5FU等药物列在那里了,或者是列在那里的药物引起macrocytic的原因其实是通过
直接损伤胞膜引起的 |
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w*******7 发帖数: 412 | 12 【 以下文字转载自 NextGeneration 讨论区 】
发信人: wonder007 (embracing everything), 信区: NextGeneration
标 题: 怀孕其间的巨细胞贫血?
发信站: BBS 未名空间站 (Thu Dec 29 18:56:49 2011, 美东)
都2个月了,从发现的时候就和OB说了,OB 自己给开的检查,有macrocytic anemia,不是
我提醒她都没意识到指标异常.后来问她要不要补充v B12 and folic acid,她说不用,
吃prenatal vitamin is enough.可是我本来就每天都吃prenatal vitamin的,想想自己
专门又去买了额外的B12 and folic acid每天吃,过了2个月了还是没有改善,MCV还是
102.今天门诊的internist 打我电话让我去查VB 12 level and methylmalonic acid
level. 说如果低去用IM injection of VB12.
我现在很不高兴,觉得我的OB怎么没有on top of everythin... 阅读全帖 |
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d********9 发帖数: 16 | 13 来自主题: MedicalCareer版 - 急问这道题 could be B or E, but more likely E, because of his drinking binge which
could be directly toxic to bone marrow and all his 3 cell lines are low.
However low Hb could be due to macrocytic anemia. |
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l**********e 发帖数: 382 | 14 来自主题: MedicalCareer版 - 急问这道题 DT usually happen 2-3 days after restricting from alcohol whcih explains his
neurological symptoms. His hemotological test shows macrocytic anemia and
follic acid deficiency is very common among alcoholics. |
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e****0 发帖数: 678 | 15 • leukemia
ALL AML CLL
child adult elderly
BM lymphoblasts 25%myeloblasts
lab Lymphocyte 5000, mature-appearing cells
• Osgood-schlatters disease
Adolescent male athletes
Traction apophysitis—quadriceps tendon put the traction on the
apophysis of the tibial tubercle where patellar tendon inserts.
A firm mass =heterotopic bone formation
Pain can be reproduced by extending the kne... 阅读全帖 |
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j******1 发帖数: 138 | 16 1.2012 FA 320页提到:low free serum Mg2+ decrease PTH secretion, why?
2.382页:为什麽MTX, trimethoprim, Vb12, folate 缺乏引起Megaloblastic anemia
, 而purine, pyridine synthesis deficiency, 5-FU, AZT, hydroxyurea引起
Nonmegaloblastic macrocytic anemia?不都是DNA合成受阻吗?这两种贫血到底怎末
区分,好像aloholics两者都可引起。迷惑中... |
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J*********4 发帖数: 1274 | 17 1.. Magnisium is required for secretion of PTH
2. don't know. Sorry.
Megaloblastic anemia=multi-lobulated neutrophil+macrocytic anemia
Alcohol inhibit folate acid absorption, also interfere with Heme synthesis.
---
I could be wrong on both. Welcome other experts! |
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x******a 发帖数: 195 | 18 Megaloblast的细胞核(成熟受阻)、细胞浆(持续合成)都大,形成的RBC体积大,很
好理解。RBC本身没有细胞核没有DNA。LZ列的那些药物是通过影响DNA合成(形成
megaloblast)而导致Megaloblastic macrocytic anemia的。
正常RBC是双凹的,膜缺陷时是圆的,体积也大了。另一种情况是reticulocytosis。
Reticulocyte体积大于RBC,而计算MCV时包含了reticulocyte,所以reticulocytosis
的情况下MCV也是大的。 |
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I****a 发帖数: 407 | 19 TTP from Plavix is very rare. I have not seen one myself. It happens within
couple of weeks after the drug is started. The mechanism is probably
different from idiopathic TTP which is generally from an immune process. The
hallmark of TTP are: thrombocytopenia and microangiopathic hemolytic anemia
(MAHA). If your father does not have both, then it is not TTP. TTP patients
generally have thrombocytopenia with normal morphology, normocytic/
macrocytic anemia due to intravascular destruction/reticul... 阅读全帖 |
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A*******s 发帖数: 9638 | 20 你的vitamin level是多少?
Vitamin B12 injection, maybe twice a month。 Folate应该是足够了。
结束pregancy后才查一下病因。
有hypothyroidism symptoms, Live function normal, no past medical history,no
family history, not on any other meds except prenatal vitamin(contain 1mg
folic acid per tablet) and oral V12. 想不出what might cause macrocytic
anemia in a young women with healthy life style and good diet. 大家帮我想想
如果你遇到我这样的病人,你怎么处理? |
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I****a 发帖数: 407 | 21 What is the severity of her anemia? TSH, reticount and a smear will help.
ETOH history is also important. |
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A*******s 发帖数: 9638 | 22 Your MCV is not that bad. I would do folate 4 mg daily if nothing else could
be found. |
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