[Mechanisms of repair after renal injury]. / Meccanismi di riparazione del danno renale.

Recovery from kidney injury through repair mechanisms often linked to inflammation is conditioned by nature and severity of the insult. In the assessment of kidney repair, functional recovery should be kept distinct from structural repair: compensatory hypertrophy/function of intact nephrons often masks the inability of the kidney to heal or replace damaged structures. The mechanisms of repair reflect three degrees of injury, differently handled by the kidney. First, repair of DNA damage is accomplished through proofreading DNA polymerases, along with other controls for sequence misalignment / nucleotide replacement. If DNA cannot be repaired, cells carrying mutation(s) are disposed of through apoptosis, which is also critical to clearing damaged kidney cells and infiltrating leukocytes in acute and chronic ischemic, immunological, or chemical damage. A second mechanism of repair is linked to proliferation of surviving cells. At least 5 types of reparative proliferation are known to occur, some of which implicate stem cell immigration from distant reservoirs, followed by in situ differentiation. A third mode of repair could be referred to as structural repair, indeed limited in the human kidney by the absence of postnatal nephrogenesis. Recovery from acute tubular necrosis involves remodelling of the proximal tubule, with a strict requirement for integrity of the basement membrane. Contrary to the current dogma that only acute injury can be repaired, whereas chronic damage leads to irreversible loss of nephrons, evidence is emerging that some degree of renal remodelling occurs even in chronic renal disease, despite the occurrence of stabilized structural changes.

[Syndrome of inappropriate ADH secretion: a late complication of hemopoietic stem cell allograft]. / Sindrome da inappropriata secrezione di ormone antidiuretico: una complicanza tardiva del trapianto di cellule staminali emopoietiche.

An 11-year old boy with acute lymphoid leukemia underwent umbilical cord stem cell infusion. This was followed at day 15 by the onset of asymptomatic hypotonic isovolemic hyponatremia. The disorder could be attributed to a syndrome of inappropriate ADH secretion (SIADH), most probably related to the massive i.v. induction treatment with cyclophosphamide. The major causes and clinical variants of SIADH are reviewed, with particular emphasis on the complications of chemotherapy in hematological diseases. Worsening of hyponatremia during routine parenteral feeding, as opposed to normalization of plasma Na+ by infusion of hypertonic saline, emphasize the importance of early accurate diagnosis and careful follow-up of these iatrogenic sequelae of stem cell allograft.

[Renal echography as a preliminary to the urographic study. Considerations on 839 cases and proposals]. / L'ecografia renale come primo momento dell'esame urografico. Considerazioni su 839 casi e prospettive.

The same radiologist, on 839 patients who were to be subjected to urography, did also preliminary ultrasonography in order to have at his disposal a greater amount of informations than those furnished by a simple abdominal X-ray. The clinical-radiological integration with such a procedure gains significance; consequently the succeeding urographic phases can be better arranged so as to improve their aim and purpose.