Irish DNA database … Хаджи-Мурат … Diapedesis, Extravasation 23rd of November, 2008 POST·MERIDIEM 10:45

We’re lucky enough to have Orna Tighe as one of our molecular medicine lecturers, and in the course of a lecture on methods of DNA and RNA analysis, she mentioned that the Republic of Ireland has a database of the DNA of everyone born in the country since 1970, stored at Temple Street Children’s Hospital. This came about because of two reasonable and not-very-shocking developments:

• Guthrie cards have been collected for decades; they’re used to screen for phenylketonuria (an inability to metabolise a common and important amino acid, easily treated with dietary changes, but leading to mental retardation if left untreated) among many other diseases. They are stored indefinitely, and have been used constructively to work out the prevalence of genetic diseases in Ireland, something important for clinical practice.
• PCR is a microbiological technique that uses the machinery of the cell’s DNA replication to generate many, many copies of an area of DNA molecule that the researchers are interested in. This makes it practical to examine in detail the DNA from a sample that may be just a few intact cells all these decades later; without it the examination of the few cells preserved would destroy them, not allowing the detail necessary for anything definitive.

Because Australia is the most competent of the post-death-of-the-British-Empire states, this has come up in discussion (and in use) there, but it doesn’t look like they’ve actually resolved it. I would be shocked to my core if the Republic has digitised the Guthrie cards or otherwise made them workable in the direction of a police state, but the data are there, it would be constructive to work out exactly what we’re going to do with them.

Chadschi Murat, Leo Tolstoy, autorisierte Übertragung von August Scholz. This is a German translation of one of Tolstoy’s last novels, about a Chechen rebel leader (and eventual supporter of the Russians) in the mid-nineteenth century. I bought it because I had seen it recommended for its action and the plot, but I was most impressed (probably in the matter of someone who has never read War and Peace!) by Tolstoy’s interpretation of the motivation and thoughts of the protagonists. It can’t really give much insight into Chechnya today—as far as I can tell, the Chechens today are like the Basques today, totally comfortable in the culture of the wider nation, but believing themselves different despite that, whereas the Chechens of the 1850s were like the Bantu at the same point or the Highland Scots in the 1650s; culturally very different in practice, very ill-at-ease with the wider society they were coming into contact with. I liked it; I’m not sure I’d recommend it to many people, it would depend on their own interests; reading the beautiful Fraktur it was printed in (first time I’ve read a book in Fraktur) was enjoyable, though.

Words of the day: Two today, and no explanation from me, just the two OED2 definitions:

diapedesis (ˌdaɪəpːˈdiːsɪs). Path.
[mod.L., a. Gr. διαπήδησις, f. διαπηδά–ειν to ooze through, f. δια– through + πηδά–ειν to leap, throb. In mod.F. diapédèse (Paré 16th c.).]
The oozing of blood through the unruptured walls of the blood-vessels.
1625 Hart Anat. Ur. ii. iv. 68 Such an excretion of bloud..is..called Diapedesis: that is, as much as a streining through.
1634 T. Johnson Parey’s Chirurg. ix. i. (1678) 216 That solution of Continuity..which is generated by sweating out and transcolation, [is termed] Diapedesis.
1866 A. Flint Princ. Med. (1880) 27 When the red blood corpuscles are pressed through the unruptured vascular wall, it is denominated hemorrhage by diapedesis.
1885 Lancet 26 Sept. 589 It is possible..that the mercury gains access to the circulation by a sort of diapedesis.
So
diape’detic a., pertaining to or of the nature of diapedesis.
In mod. Dicts.

extravasation (ɛkˌstrævəˈseɪʃən). [f. extravasate v.: see -ation. Cf. F. extravasation.]
1. Path. The escape of an organic fluid (e.g. blood, sap) from its proper vessels into the surrounding tissues; an instance of this.
1676 Wiseman Surgery 2 The Plenitude of Vessels..causeth an Extravasation of bloud.
1796 Morse Amer. Geog. I. 338 A stagnation and extravasation of the juices of the stalk.
1836 Todd Cycl. Anat. I. 400/1 The extravasation of urine.
1877 Roberts Handbk. Med. I. 28 Points of redness..due to minute extravasations of blood.
fig.
1685 Burnet Lett. (1687) 143 Such an extravasation..of silver, occasions a great deadness in Trade.
1691 Beverley Mem. Kingd. Christ 9 God having suffer’d..so dangerous an Extravasation of the French Power.
b. A mass or spot of extravasated blood.
1836 Todd Cycl. Anat. I. 52/2 On the substance of the extravasation there were a..number of spots of red blood.
1878 A. Hamilton Nerv. Dis. 19 The crura and pons are to be examined carefully for softening extravasations.
2. Geol. Effusion (of molten rock) from a subterranean reservoir; also, a deposit so formed.
1842 G. P. Scrope Volcanos 9 To permit an extravasation of some of the heated and liquefied and gaseous matters.
1864 C. P. Smyth Our Inheritance ii. viii. (1880) 144 Amongst the veins and extravasations of granite and basalt.