Daño renal agudo debido a un síndrome de lisis tumoral espontáneo como primera manifestación del linfoma de Burkitt / Acute kidney injury caused by spontaneous tumour lysis syndrome as first sign of Burkitt lymphoma

El síndrome de lisis tumoral espontáneo (SLTE) es una causa excepcional de daño renal agudo (DRA) en la infancia. Describimos un caso de DRA secundario a SLTE como primera manifestación de un linfoma de Burkitt. Se trata de un niño de 5 años de edad, con anorexia de 1 mes de evolución, niveles sanguíneos elevados (mg/dL) de urea/creatinina (337/7,21), ácido úrico (30,4) y fósforo (7), y unas cifras de potasio de 6,6 mEq/L, que presenta unos riñones grandes e hiperecogénicos en la ecografía abdominal. Experimentó una mejoría progresiva de la función renal tras el inicio de tratamiento con rasburicasa e hiperhidratación. El día +14 empeoró clínicamente; se repitió la ecografía y se detectó una gran masa retroperitoneal, por lo que se realizó una biopsia. Durante el procedimiento, tras administrar dexametasona (protocolo de intubación), presentó taquicardia ventricular secundaria a hiperpotasemia (9 mEq/L), que revirtió sin cardioversión. Precisó hemofiltración durante 48 horas. Tras el diagnóstico anatomopatológico de linfoma de Burkitt, se inició un tratamiento específico, y actualmente el paciente está en remisión. Ante un caso de DRA con hiperuricemia, hiperfosforemia e hiperpotasemia, debemos sospechar un SLTE, descartar un proceso tumoral oculto y evitar la administración de esteroides, ya que puede resultar catastrófica (AU)

Spontaneous tumour lysis syndrome (STLS) is an extraordinary cause of acute kidney injury (AKI). We report a case of AKI caused by STLS as first sign of Burkitt lymphoma. Five-year-old boy with one month history of anorexia, elevated levels in blood (mg/dL) of urea/creatinine (337/7.21), uric acid (30.4), phosphorous (7); potassium 6.6 mEq/L, and large echogenic kidneys in abdominal ultrasound. Progressive improvement in kidney function was evident after starting rasburicase and hyperhydratation therapy. On day +14, abdominal ultrasound was performed because of clinical deterioration and it showed a big retroperitoneal mass, which was biopsied. During the procedure, after dexamethasone administrations (intubation protocol), he suffered ventricular tachycardia, reverted without cardioversion. 48 hours haemodiafiltration was needed. The biopsy showed Burkitt lymphoma, specific treatment was started and the boy is nowadays in remission. In the case of AKI with hyperphosporemia, hyperkaliemia and hyperuricemia suspecting STLS is mandatory and avoid steroid therapy as it could be live threatening (AU)

Carnosol, radiation and melanoma: a translational possibility

PURPOSE: To compare the genoprotective and radioprotective effect of carnosol (COL) against damage induced by ionizing radiation with similar effects produced by different antioxidant compounds. METHODS: The genoprotective effect was studied by means of the micronucleus test for antimutagenic activity in which the reduction in the frequency of micronuclei was evaluated in cytokinesis-blocked cells of human lymphocytes. The radioprotective effects were studied by cell viability test (MTT) in PNT2 (normal prostate) and B16F10 (melanoma) cell lines when they were administered before exposure to different X-ray doses (4, 6, 8, 10 and 0 Gy). RESULTS: Carnosol shows a significant genoprotective capacity (p < 0.001) against radiation with a protection factor of 50 %, and a dose-reduction factor of 4.3. Cell survival obtained with COL administered before exposure to 10 Gy of X-rays showed a protection factor of 55.1 %, eliminating 39 % of radiation-induced cell death in normal epithelial cells of prostate (PNT2) (p < 0.001). However, in the melanoma cell lines (B16F10) assayed, COL acted not as a radioprotector, but as a sensitizing agent increasing the cellular death by 34 % (p < 0.01) and producing an enhancement ratio of 2.12. CONCLUSIONS: Carnosol may be developed as a radioprotective agent in the non-tumoral cells. However, in the B10F16 melanoma cells, melanogenesis is activated by COL leading to redistribution of the enzymatic balances of glutathione and cysteine-lyase production, which could compromise the intracellular redox defence system. This effect appears as an increase in the capacity of ionizing radiation-induced damage, and thus exhibits a paradoxical protective effect of COL on melanoma cells (AU)

Zoledronic acid and radiation: toxicity, syergy or radiosensitization?

INTRODUCTION: Zoledronic acid (Z) is a bisphosphonate used in hypercalcaemia-related cancer, in complications for bone metastasis and in postmenopausal osteoporosis and it has been related to osteoradionecrosis, especially when associated with radiation to the head and neck structures.OBJECTIVES: To determine the radiosensitization capacity of zoledronic acid in the combined treatment with ionizing radiation (IR) by evaluating its genotoxic and cytotoxic capacities in non-tumoral cells. MATERIALS AND METHODS: The genotoxic effect of Z was studied by means of the micronucleus test in cytokinesis-blocked cells of human lymphocytes irradiated before and after a 2 Gy irradiation, while the cytotoxic effect was studied by a cell viability test in the PNT2 cell line before and after exposure to different X-ray doses (0-20 Gy) in four groups (Z alone, radiation alone, Z + IR and IR + Z). RESULTS: A dose-dependent and time-dependent cytotoxic effect of Z and IR on PNT2 cells in vitro (p > 0.001) was demonstrated. With the concentrations recommended for humans, the combined treatment had a more pronounced effect than individual treatments (p < 0.001). The effect was synergic (CI < 1), increasing the Z enhancement ratio (2.6) and sensitization factor (56 %); the effect of Z was always greater after IR exposure. In the genotoxic effect, only the administration of Z after irradiation (IR + Z) increased chromosome damage (p < 0.001) and the sensibilization factor (35.7 %). CONCLUSION: High concentrations of Z are toxic, but the concentrations recommended for clinical practice in humans give it the characteristics of a radiosensitization agent, whose effect is even greater when administered after IR (AU)

Zoledronic acid and radiation: toxicity, synergy or radiosensitization?

INTRODUCTION: Zoledronic acid (Z) is a bisphosphonate used in hypercalcaemia-related cancer, in complications for bone metastasis and in postmenopausal osteoporosis and it has been related to osteoradionecrosis, especially when associated with radiation to the head and neck structures. OBJECTIVES: To determine the radiosensitization capacity of zoledronic acid in the combined treatment with ionizing radiation (IR) by evaluating its genotoxic and cytotoxic capacities in non-tumoral cells. MATERIALS AND METHODS: The genotoxic effect of Z was studied by means of the micronucleus test in cytokinesis-blocked cells of human lymphocytes irradiated before and after a 2 Gy irradiation, while the cytotoxic effect was studied by a cell viability test in the PNT2 cell line before and after exposure to different X-ray doses (0-20 Gy) in four groups (Z alone, radiation alone, Z + IR and IR + Z). RESULTS: A dose-dependent and time-dependent cytotoxic effect of Z and IR on PNT2 cells in vitro (p > 0.001) was demonstrated. With the concentrations recommended for humans, the combined treatment had a more pronounced effect than individual treatments (p < 0.001). The effect was synergic (CI < 1), increasing the Z enhancement ratio (2.6) and sensitization factor (56 %); the effect of Z was always greater after IR exposure. In the genotoxic effect, only the administration of Z after irradiation (IR + Z) increased chromosome damage (p < 0.001) and the sensibilization factor (35.7 %). CONCLUSION: High concentrations of Z are toxic, but the concentrations recommended for clinical practice in humans give it the characteristics of a radiosensitization agent, whose effect is even greater when administered after IR.

Carnosol, radiation and melanoma: a translational possibility.

PURPOSE: To compare the genoprotective and radioprotective effect of carnosol (COL) against damage induced by ionizing radiation with similar effects produced by different antioxidant compounds. METHODS: The genoprotective effect was studied by means of the micronucleus test for antimutagenic activity in which the reduction in the frequency of micronuclei was evaluated in cytokinesis-blocked cells of human lymphocytes. The radioprotective effects were studied by cell viability test (MTT) in PNT2 (normal prostate) and B16F10 (melanoma) cell lines when they were administered before exposure to different X-ray doses (4, 6, 8, 10 and 0 Gy). RESULTS: Carnosol shows a significant genoprotective capacity (p < 0.001) against radiation with a protection factor of 50 %, and a dose-reduction factor of 4.3. Cell survival obtained with COL administered before exposure to 10 Gy of X-rays showed a protection factor of 55.1 %, eliminating 39 % of radiation-induced cell death in normal epithelial cells of prostate (PNT2) (p < 0.001). However, in the melanoma cell lines (B16F10) assayed, COL acted not as a radioprotector, but as a sensitizing agent increasing the cellular death by 34 % (p < 0.01) and producing an enhancement ratio of 2.12. CONCLUSIONS: Carnosol may be developed as a radioprotective agent in the non-tumoral cells. However, in the B10F16 melanoma cells, melanogenesis is activated by COL leading to redistribution of the enzymatic balances of glutathione and cysteine-lyase production, which could compromise the intracellular redox defence system. This effect appears as an increase in the capacity of ionizing radiation-induced damage, and thus exhibits a paradoxical protective effect of COL on melanoma cells.

Evolution of diagnostic reference levels in Spanish intraoral radiology.

A total of 16 175 official reports of quality assurance on dental radiodiagnostic surgeries from 16 Spanish autonomous regions compiled during 2002-09 were studied to determine the evolution of diagnostic reference levels (DRLs) for obtaining a diagnostic image in the normal conditions of clinical practice in Spanish dental clinics. A DRL of 3.1 mGy was set in 2009, which represents a 35.4 % decrease compared with the dose determined in 2002 (4.8 mGy). During the same period, the mean dose fell by only 17.2 %. The DRL recommended by the European Union in 2004 for intraoral radiology is 4 mGy, and this study shows that 83.4 % of the installations used a dose below this. Of the installations using indirect or direct digital systems 1.1 and 1.2 %, respectively, used doses higher than those recommended, while 14.2 % of those using radiographic film exceeded this limit.

Chemical genoprotection: reducing biological damage to as low as reasonably achievable levels.

OBJECTIVES: The aim of this study was to evaluate the antioxidant substances present in the human diet with an antimutagenic protective capacity against genotoxic damage induced by exposure to X-rays in an attempt to reduce biological damage to as low a level as reasonably possible. METHODS: Ten compounds were assessed using the lymphocyte cytokinesis-block micronucleus (MN) cytome test. The compounds studied were added to human blood at 25 µM 5 min before exposure to irradiation by 2 Gy of X-rays. RESULTS: The protective capacity of the antioxidant substances assessed was from highest to lowest according to the frequency of the MN generated by X-ray exposure: rosmarinic acid = carnosic acid = δ-tocopherol = l-acid ascorbic = apigenin = amifostine (P < 0.001) > green tea extract = diosmine = rutin = dimetylsulfoxide (P < 0.05) > irradiated control. The reduction in genotoxic damage with the radiation doses administered reached 58%, which represents a significant reduction in X-ray-induced chromosomal damage (P < 0.001). This degree of protection is greater than that obtained with amifostine, a radioprotective compound used in radiotherapy and which is characterised by its high toxicity. CONCLUSION: Several antioxidant substances, common components of the human diet and lacking toxicity, offer protection from the biological harm induced by ionizing radiation. Administering these protective substances to patients before radiological exploration should be considered, even in the case of small radiation doses and regardless of the biological damage expected.