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- 1 older entries
- 2 Simple test for sickle cell carriers
- 3 Cerebral vasculopathy
- 4 More treatment, vicar?
- 5 Vaso-occlusion
- 6 Transition of care
- 7 Eurocentrism!
- 8 Guidelines
- 9 Updating
- 10 Suggestion for Prognosis Section
- 11 Origin of SCD
- 12 Sicklemic Belt
- 13 Sickle-cell disease's relation to malaria
- 14 No access
- 15 History section
- 16 Addition about evolution
- 17 Reproductive issues
Just as a comment for further discussion, I did hemoglobin research for about 4 and a half years. I recall a conversation (ca 1993 or 1994) with Professor Gary Ackers (at the time, chair of biochemistry and molecular biophysics at Washington University in St Louis Medical School, and one of the leading experts on hemoglobin cooperativity) about a paper, in which they mapped the site of action of the digestive enzyme the malaria parasite used on hemoglobins (as Hb is what they eat). It turns out that in the process of polymerization (HB S now, the sickle cell Hb), the polymerization caps the site of digestion, making Hb a poor meal for the parasite. That, to my understanding, was the way that in heterozygous individuals the mutation had selective pressure against the parasite. It slowed the rate of growth, because they couldn't feed as effectively on heterozygous individuals. Inter-cell death seems to be a poor mechanism for selective pressure, as few cells are sickled in heterozygous individuals. dwmyers
Simple test for sickle cell carriers
I read this in a test on genetics in GCSE Biology. If a sample of a carrier's blood is kept in low oxygen conditions, a few cells with become sickle shaped. This is roughly what the test said:
A couple are worried that they might pass on sickle cell anaemia to their children, so they had blood samples taken for a test. The father's sample developed sickle cells in low oxygen conditions whereas the mother's didn't. What does this mean?
Of course, it meant that the couple's children would a half chance of becoming a carrier, but won't develop the disease. But since I can't obtain the paper, I can't prove that it was there, but I doubt that it's a lie.
doi:10.1111/bjh.12300 Br J Haem 14:54, 25 April 2013 (UTC)
More treatment, vicar?
Transition of care
Why are sickle type red blood cells "abnormal", and disc type red blood cells "normal"?
is the evolutionary immunity to plague and smallpox abnormal?
- I don't see where Eurocentrism comes into play, but if you read any of the article you'd see that infarcts to vital organs, severe pain, a shortened lifespan, and the fact that most people in the world do not have sickling cells would likely be the reason sickle cells are considered abnormal.MartinezMD (talk) 23:05, 17 January 2014 (UTC)
- And NICE: National Institute for Health and Clinical Excellence. Clinical guideline 143: Sickle cell acute painful episode. London, 2012. JFW | T@lk 08:54, 14 September 2014 (UTC)
Some other recent secondary sources (MESH "Anemia, Sickle Cell"[MAJR] with "Review"):
- doi:10.1111/bjh.12879 Br J Haem 2014 - pain control and safety (opioids)
- doi:10.1111/bjh.12950 Br J Haem 2014 - splenic pathology
- doi:10.1161/STROKEAHA.114.005144 Stroke 2014 - role in stroke
- doi:10.3810/pgm.2014.03.2748 Postgrad Med 2014 - psychological and pathological aspects of pain control in children
- doi:10.1136/bmj.g1765 - BMJ 2014 - management in the community
- doi:10.1182/blood-2013-12-542076 Blood 2014 - sickle hepatopathy and transplantation
- doi:10.1182/blood-2013-01-435776 Blood 2014 - status of HSCT for haemoglobinopathy
For the epidemiology and the management in resource-poor settings we might need to refer to the WHO literature.
- doi:10.1586/ehm.12.20 is about the research into histone deacetylase inhibition, for the "research" section. JFW | T@lk 22:21, 28 October 2014 (UTC)
Having identified some sources (previous section) I am planning to update this article and bring it to GA status reasonably soon. It gets the basics right but there's a fair number of sources that don't meet WP:MEDRS and at places it is difficult to understand for the lay reader. Some other WP:MEDMOS problems were also present. There's a total of 29 Cochrane reviews (link), but we're only citing four Cochrane reviews currently.
My views for each section:
- Signs and symptoms: currently a little bit chaotic and doesn't separate acute from chronic problems
- Genetics: a fair bit of jargon needs "opening up"
- Pathophysiology: should be maximally up to date according to current understanding (needs 2-3 solid sources)
- Diagnosis: screening/case finding should be separated from diagnostics in the setting of complications (e.g. stroke) and surveillance; we need to talk about neuroimaging and echocardiography
- Prevention: there is currently no section that discusses prevention strategies; I haven't yet seen sources that discuss premarital screening and counseling in the same way Cyprus attempts to reduce unions that might lead to thalassaemia major
- Management: again we need to separate prophylaxis, acute care, and long-term disease management
- Prognosis: this needs strong sources to be reliable for the average reader
- Epidemiology: good sources needed, perhaps less on a country-by-country basis
- History: the current section needs consolidating with a better secondary source as support
- Research directions: needs to be written
- As far as the history section, the most recent dates are from the 1940's-50's. I'm sure something has happened or been discovered about sickle-cell disease since then. Wulf.174 (talk) 00:04, 2 October 2014 (UTC)
Suggestion for Prognosis Section
In this article, it states that "the estimated mean survival for sickle-cell patients was 53 years old for men and 58 years old for women with homozygous SCD." Throughout the entire article it also talks about much lower life expectancies are for individuals that have SCD. My question is, should this life expectancy be compared to the typical European/American life expectancies (which would be relatively high) or the life expectancy of people living in areas where SCD is much more common? These areas are typically much more impoverished and likely have much lower life expectancies as it is. In this case, 53 years of age for men and 58 years of age for women does not seem like it would be too far removed from the life expectancies of the people living in these traditionally malaria-stricken countries. Their average life expectancy at least be given in order to have a good reference point for how people with SCD compare. — Preceding unsigned comment added by Haynes.239 (talk • contribs) 03:32, 1 October 2014 (UTC)
I will get back to you on this one.
Origin of SCD
In the article, it says that "Sickle-cell gene mutation probably arose spontaneously in different geographic areas, as suggested by restriction endonuclease analysis. These variants are known as Cameroon, Senegal, Benin, Bantu and Saudi-Asian." A study done in 1988 only traces the origins of mutation back to three places, namely Benin, Senegal, and Central African Republic (Nigon, 1988). This is information appears to be inconsistent with what is known about the origin of SCD. — Preceding unsigned comment added by Haynes.239 (talk • contribs) 03:44, 1 October 2014 (UTC)
Yes. Nigon, V. "Structural Analysis of the 5 Prime Flanking Region of The. Beta. Globin Gene in African Sickle Cell Anemia Patients: Further Evidence for Three Origins of the Sickle Cell Mutation in Africa." (1988). Print. Haynes.239 (talk) 01:09, 15 October 2014 (UTC)
- Print where? A journal? A book? Looks like a primary source too. JFW | T@lk 17:01, 19 October 2014 (UTC)
The name of the area that has the highest frequency of persons infected with SCD is called the "Sicklemic Belt" (Lehman and Huntsman, 1974). I think this needs to be mentioned, as the particular region does have a more specific name. — Preceding unsigned comment added by Haynes.239 (talk • contribs) 03:51, 1 October 2014 (UTC)
- Never heard of the term, and I don't think we need to mention it. JFW | T@lk 23:13, 6 October 2014 (UTC)
Sickle-cell disease's relation to malaria
There should be more ties to how sickle-cell disease is shaping certain African populations, and how these populations no longer have a high rate of malaria like they previously did. There are only brief areas on the page that mention how malaria and sickle-cell disease relate to each other, but I believe there should be a bigger section that ties it together. Wulf.174 (talk) 23:48, 1 October 2014 (UTC)
- Point us to a source that looks into this, and we can have that conversation. JFW | T@lk 23:13, 6 October 2014 (UTC)
The following source was temporarily removed:
I have removed the content that I could not trace to secondary sources. It is reproduced here for reference:
|“||An association with pigmented gall stones was noted in 1911 by Washborn. A genetic basis for this disease was proposed in 1915 by Cook and Meyer. The disease was named sickle-cell anaemia in 1922 by Verne Mason after several additional cases were reported. All the known cases had been reported in blacks and he concluded that this disease was confined to those of black African descent. The heterozygous condition was independently recognised in 1923 by Huck and Syndestrickler. Syndestrickler also was the first to note the splenic atrophy that occurs in this condition. It was recognised as a Mendelian autosomal characteristic by Taliaffero and Huck also in 1923. A predisposition to pneumonia was noted in 1924 by Graham. The concept of progressive splenic atrophy was proposed by Hahn and Gilespie in 1927. Pneumococcal meningitis in this condition was first reported in 1928 by Wollstein and Kriedel but it was not until 1966 that the association between splenic atrophy and infection was made by Robinson and Watson.
In 1927 Vernon Hahn and Elizabeth Biermann Gillespie showed that sickling of the red cells was related to low oxygen. In some individuals this change occurs at partial pressures of O
The association with kidney and lung infarcts was noted in 1931 by Yater and Mollari and Baird in 1934 respectively. The term sickle-cell trait was coined by Samuel Diggs in Memphis in 1933 to distinguish heterozygotes from those with sickle-cell anaemia. Diggs also reported the association with splenic fibrosis in 1935. The pathological mechanism of vaso-occlusion was proposed by Ham and Castle in 1940.
In 1946, E A Beet, a British medical officer stationed in Southern Rhodesia (Zimbabwe), observed that blood from malaria patients who had sickle-cell trait had fewer malarial parasites than blood from patients without the trait and suggested that this might be a protective feature. In 1947 Beet published that the incidence of enlarged spleens in sickle-cell patients was much lower than in non sickle-cell and suggested that this was due to recurrent thromboses which resulted in fibrosis and shrinkage of the spleen. In 1949 Lehmann and Raper published a map of Uganda and showed that the presence of sickle-cell anaemia correlated with the presence of malaria. In 1950 Singer et al. noted the abrupt cessation of marrow activity that may occur and coined the term aplastic crisis. The role of parvovirus in aetiology of this condition was not recognised until 1981. P. Brain also while working in Northern Rhodesia confirmed the lower incidence of splenomegaly and suggested that while homozygotes for the sickle-cell gene suffered from several problems heterozygotes might be protected against malaria.