Metahemoglobinemia. Causa de cianosis en el niño / Methemoglobinemia. Cause of cyanosis in the child

La metahemoglobina (MHb) es una forma de hemoglobina que presenta el hierro del grupo hem en estado férrico (oxidado), minimizando su captación y transporte de oxígeno. La metahemoglobinemia se produce cuando, por causa genética, los mecanismos redox son insuficientes, o bien si, de forma adquirida, la cantidad de sustancias oxidantes superan los mecanismos redox del hematíe. Presentamos dos casos clínicos, el primero de los cuales es un lactante que, tras una exposición prolongada a una sustancia oxidante (parche de lidocaína-prilocaína [EMLA®]), presenta cianosis con repercusión hemodinámica, niveles elevados de MHb y respuesta al azul de metileno. El segundo caso es el de una niña con cianosis desde el nacimiento, en la que se constató un déficit de citocromo b5 reductasa. Ante un paciente cianótico sin causa infecciosa, respiratoria o cardiológica conocida, y sin respuesta a la oxigenoterapia, es necesario descartar la metahemoglobinemia (AU)

The methemoglobin (MHb) is a form of hemoglobin which shows iron “hem” in ferric (oxidized), while minimizing its uptake and oxygen transport. Methemoglobinemia occurs when by the genetic cause the redox mechanisms are insufficient or if acquired by the amount of oxidizing substances which exceed the redox mechanism of red blood cells. We present two clinical cases, the first being an infant after prolonged exposure to an oxidizing substance (EMLA® patch) presented with hemodynamic cyanosis, high levels of MHb and response to methylene blue. The second patient was a girl with cyanosis since birth in which there was a deficit of cytochrome b5 reductase. Before acyanotic patient without infectious, respiratory and cardiovascular known cause and without a response to oxygen therapy it is necessary to exclude methemoglobinemia (AU)

[Aseptic bone necrosis following reimplantation of a degloving finger]. / Nécrose osseuse aseptique après réimplantation d'un dégantement digital.

We report a case of microsurgical replantation of a degloved finger in a manual worker. Four months following replantation, avascular necrosis of the middle and distal phalanges was apparent. Amputation at the level of the proximal phalanx was performed. Re-plantation is the solution of choice for such degloving injuries, but a different flap can be used if replantation is not possible. Avascular necrosis of bone is an unfrequent complication, but surgeons should be aware of it.

[Syringomatous tumor of the nipple. A case report and review of the literature]. / Tumeur syringomateuse du mamelon. Un cas rapporté avec revue de la littérature.

The authors report a case of syringomatous tumor of the nipple in a 35-year-old woman, discovered incidentally during investigation of dysmenorrhea. After limited resection-biopsy of a cystic nipple tumor, histological results indicated the need for a partial central mastectomy with areola and nipple amputation. Although this tumor is classified as an adenoma, considered to be a benign lesion, syringomatous adenoma of the nipple is a potentially locally aggressive tumor, at risk of local recurrence and deep invasion of the mammary gland. This is a rare tumor (only 18 cases have been reported in the literature), and the histological diagnosis can be difficult, with possible confusion with a nipple duct adenoma, or tubular carcinoma.

Association of hepatosplenic schistosomiasis with HLA-DQB1*0201.

Major histocompatibility class II alleles of 351 persons living in an area endemic for Schistosoma mansoni in northeastern Brazil were characterized at three loci (DRB1, DQA1, and DQB1). Contingency analyses were used to compare allele frequencies with high egg excretion, proliferative response to schistosome soluble egg antigens (SEA), and occurrence of severe, biopsy-confirmed hepatosplenic disease. There were no associations of HLA-DR or DQ with egg excretion. Patients positive for DRB1*01, DQA1*0101, or DQB1*0501 were less likely to respond to SEA than was the overall study population. However, using stringent Bonferroni correction (multiplying P values by the number of alleles tested; P x 35), none of these associations with SEA responsiveness remained significant. Hepatosplenic disease was less likely in patients positive for DRB1*11 and was more likely in patients positive for DRB1*07 or DQB1*0201. However, only the DQB1*0201 association remained significant (odds ratio = 3.72; P < .005) following Bonferroni correction.