Catastrophic antiphospholipid syndrome in a patient with Down syndrome.

We report a patient with Down syndrome, under treatment with carbamazepine, levopromazine and clonazepam. After urinary infection he developed glans necrosis requiring excision of prepuce. Six hours post surgery he presented right-hand ischemia followed by arterial and venous thrombosis of the right thoracic extremity. Later, he progressed to a compartment syndrome and presented ischemia of toes. All the clinical manifestations developed over a week. Anticardiolipin (aCL) antibodies, lupus anticoagulant and perinuclear antineutrophil antibodies were positive. Anticoagulant and immunosuppressive treatment were initiated. Owing to the failure of both treatments, the patient underwent amputation of right hand and a toe. Histopathology revealed recent and old thrombosis of medium- and small-sized vessels without vasculitis. Diagnosis of catastrophic antiphospholipid syndrome (CAPS) was made. At present, the patient continues on oral anticoagulants, IgG aCL remains positive, and no further episodes of thromboses have been observed after 4 years of follow-up. To our knowledge, this is the first case of CAPS in a patient with Down syndrome.

Beneficial effect of retinoic acid on the outcome of experimental acute renal failure.

BACKGROUND: Retinoic acid (RA) exerts beneficial effects on vascular remodelling and experimental nephritis, and plays a role in kidney development. Pathological changes caused by acute renal failure (ARF) result in high mortality. We determined whether RA ameliorates ARF-induced pathology caused by potassium dichromate (PD). METHODS: Adult Wistar female rats (210-250 g) were randomly allocated to four groups: (i) an ARF group that received PD [15 mg/kg body weight (bw), single dose subcutaneously]; (ii) a group that received PD plus RA (1 mg/kg bw) beginning at 5 days before PD and that continued for 14 additional days; (iii) a group that received PD plus thyroxine (T(4); 8 micro g/100 g bw) with RA; and (iv) a group that received only the vehicle for PD (saline solution). We evaluated functional, biochemical and morphological characteristics of the kidneys. RESULTS: PD-induced alterations in serum creatinine, creatinine clearance (C(cr)) and fractional excretion of sodium (FeNa) were less severe when rats received RA. PD increased lipoperoxidation and this alteration was partially blocked by RA. Animals undergoing ARF showed severe histological injury (brush border loss, acidophilia, oedema, pyknosis, karyorhexis, cell detachment and disruption of the basement membrane). These alterations were less severe in RA-treated rats, indicating a protective effect on functional and morphological alterations. Alterations in urinary sediment were reduced by RA. The simultaneous administration of T(4) with RA did not produce additional protection. CONCLUSION: RA exerted beneficial effects on the duration and severity of renal damage induced by PD in a model of renal failure resembling ARF in humans. The protective effect of RA may be mediated by diminished lipoperoxidative damage.

Alteración de la permeabilidad glomerular en hipertensión renovascular: participación de angiotensina y lesiones estructurales / Glomerular permeability changes in renovascular hypertension: role of angiotensin and structural lesions

Para caracterizar la disminución de permeabilidad glomerular que ocurre en el riñón contralateral en la hipertensión renovascular, se estudió la hemodinámica glomerular en ratas con hipertensión de Goldblatt y en controles normales. Se evaluó el efecto del captopril y de la vasodilatación renal inducida con plasma hiperoncótico. Además se hicieron estudios de morfometría glomerular. En dicha hipertensión se encontró aumento de la presión capilar glomerular, disminución del coeficiente de ultrafiltración (Kf), filtración glomerular por nefrona normal y elevación de resistencia aferente. El captopril elevó la filtración sólo en las normotensas, pero el Kf aumentó en ambos grupos. El plasma hiperoncótico elevó 98% la filtración y 48% y el Kf en normotensas, mientras que en las hipertensas sólo aumentó 15% la filtración y el Kf disminuyó 6%. Los estudios morfométricos mostraron dilatación de las asas capilares y aumento del volumen glomerular. La semejanza en la respuesta al captopril en ambos grupos sugiere que la reducción del Kf en la hipertensión es independiente de la angiotensina; la falta de respuesta a la vasodilatación por plasma hiperoncótico sugiere que sea producida por alteraciones estructurales de la pared capilar que disminuyen la permeabilidad hidráulica, pues el aumento en el volumen glomerular indica aumento del área de filtración