Page 524 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

508 PART 7 ■ Principles and Disorders of Hemostasis and Thrombosis

Mutations ea to absent or non unctiona MRP6 ro-

tein. So e stu ies suggest that the MRP6 rotein sti u-

ates the re ease o a enosine tri hos hate (A P) ro ce s.

A shortage o MRP6 ay i air the re ease o A P ro

ce s. A P can be broken own into other o ecu es, inc u -

ing a enosine ono hos hate (AMP) an yro hos hate.

Pyro hos hate he s contro e osition o ca ciu an

other inera s in the bo y. Consequent y, itt e yro hos-

hate is ro uce , an ca ciu an other inera s accu u- FIGURE 26.6 Seni e, or actinic, ur ura. Ecchy oses are res-

ate in e astic bers o the skin, eyes, b oo vesse s, an other ent on the orsa orear s in an e er y erson. (Fro Goo heart

tissues. HP. Goodheart’s Photoguide o Common Skin Disorders, 2n e ,

Minera ization o the arteries that carry b oo ro the Phi a e hia, PA: Li incott Wi ia s & Wi kins, 2003.)

heart to the rest o the bo y ay cause other signs an sy -

to s o PXE. For exa e, atients with this con ition can as a resu t o oss o subcutaneous at an changes in both

eve o narrowing o the arteries (arteriosc erosis) or a con- the a ount an qua ity o co agen. He ostasis tests are

ition ca e c au ication that is characterize by cra ing nor a .

an ain uring exercise because o ecrease b oo f ow to It is i ortant to istinguish seni e ur ura ro other

the ar s an egs. acquire b ee ing isor ers in the e er y. He ostatic ba -

ance changes with a vancing age, which ay be ue to
Scurvy actors such as ate et activation, increase o certain c ot-

Hu ans require ietary vita in C to ro ote the e ti y ting actor roteins, s owing o the brino ytic syste ,

hy roxy ation o roco agen. In the absence o vita in C, an o i cation o the en othe iu an b oo f ow. T is

co agen stran s are weakene as a resu t o abnor a tri e usua y re is oses the e er y to thro bosis rather than

he ica structures. Abnor a co agen resu ts in e ective b ee ing.

erivascu ar su ortive tissues, re is oses a atient to ca -

i ary ragi ity, e aye woun hea ing, etechiae an ur- Purpura Associated w ith Infections

ura (Fig. 26.5), ora b ee ing, an a so b ee ing in urinary Pur ura associate with irect en othe ia ce a age ay

an igestive tracts.
resu t ro hysica or che ica injury to the tissue cause

Solar Purpura (Senile Purpura) by icrobia agents associate with acute ebri e i ness with
etechiae, rickettsia iseases, Brazi ian ur ura ever, rat
Patients with seni e ur ura have esions that are co - bite ever, he orrhagic ever, Vibrio vulnif cus in ection, an

on y on the han s an orear s (Fig. 26.6), without any the arasitic in ection, Strongyloides.

known rece ing trau a. T e skin in e er y eo e is thin
T e overa action o en othe ins, a a i y o e ti es, is

to increase b oo ressure an vascu ar tone. Bacteria toxins

ro uce een othe ia ization in uce by an en otoxin.

Purpura Related to Miscellaneous Causes

Disor ers in this category can be the resu ts o contact er-

atitis, steroi use, or rug reactions. Other causes o ur-

ura can be associate with vascu ar a ignancy. Pur ura

o this origin is observe in Ka osi sarco a an vascu ar

tu ors.

Pur ura si ex ha ens o en in wo en an a ears

in the ti e o enstrua erio . T is ty e is ex aine with

the hor ona inf uence that is resent uring the enstrua

cyc e. I the enstruation is ain u , taking nonsteroi a

anti-inf a atory rug (NSAID) or ain re ieving a i-

tiona y creates exce ent environ ent or ur ura si ex.

Unusua causes o ur ura inc u e actitious or se -

i ose ur ura an re igious stig ata.

NOTE: This is a good time to review the de nitions of the

Key Terms in the Glossary and ash cards on . It is
FIGURE 26.5 T e egs o a 46-year-o an with scurvy. (Fro also a good time to complete Review Questions related to
Cha e PC, Harvey RA, Ferrier DR, Biochemistry, 4th e , preceding content.

Phi a e hia, PA: Li incott Wi ia s & Wi kins, 2007.)