Superoxide, nitric oxide and peroxynitrite production by macrophages under different physiological oxygen tensions.

Macrophages count on two O2-consuming enzymes to form reactive radical species: NAPDH oxidase 2 (Nox2) and nitric oxide synthase 2 (inducible isoform, iNOS) that produce superoxide radical (O2•-) and nitric oxide (•NO), respectively. If formed simultaneously, the diffusion-controlled reaction of O2•- and •NO yields peroxynitrite, a potent cytotoxic oxidant. In human tissues and cells, the oxygen partial pressure (pO2) normally ranges within 2-14 %, with a typical average pO2 value for most tissues ca. 5 %. Given that O2 is a substrate for both Nox2 and iNOS, its tissue and cellular concentration can affect O2•- and •NO production. Also, O2 is a modulator of the macrophage adaptative response and may influence iNOS expression in a hypoxia inducible factor 1-α (HIF1α-)-dependent manner. However, most of the reported experiments in cellula, analyzing the formation and effects of O2•- and •NO during macrophage activation and cytotoxicity towards pathogens, have been performed in cells exposed to atmospheric air supplemented with 5 % CO2; under these conditions, most cells are exposed to supraphysiologic oxygen tensions (ca. 20 % O2) which are far from the physiological pO2. Here, the role of O2 as substrate in the oxidative response of J774A.1 macrophages was explored upon exposure to different pO2 and O2•- and •NO formation rates were measured, obtaining a KM of 26 and 42 µM O2 for Nox2 and iNOS, respectively. Consequently, peroxynitrite formation was influenced by pO2, reaching a maximum at ≥ 10 % O2, but even at levels as low as 2 % O2, a substantial formation rate of this oxidant was detected. Indeed, the cytotoxic capacity of immunostimulated macrophages against the intracellular parasite T. cruzi was significant, even at low pO2 values, confirming the role of peroxynitrite as a potent oxidizing cytotoxin within a wide range of physiological oxygen tensions.

Displasia septo-óptica (síndrome de De Morsier) con hipopituitarismo y sus múltiples complicaciones: reporte de un caso y revisión de literatura

Presentamos el caso de una paciente con displasia septo-óptica (SOD), también conocida como síndrome de De Morsier, un desorden congénito raro. Se caracteriza por una combinación de alteraciones: hipoplasia del nervio óptico, disfunción hipofisaria y anormalidades de la línea media. Presentamos el caso de una paciente de 37 años con síndrome de De Morsier que consulta por infertilidad. Asocia hipopituitarismo, con déficit de hormona de crecimiento e hipogonadismo hipogonadotrófico, diagnosticada a los 11 años, en contexto de hipocrecimiento e impuberismo. También presenta complicaciones asociadas a estos déficits, como infertilidad, síndrome metabólico y compromiso óseo. Un diagnóstico y tratamiento temprano puede prevenir la morbimortalidad asociada a este síndrome, pero no así la infertilidad. Sin embargo, es posible lograr el embarazo mediante inducción de la ovulación.

The study presents the case of a patient with septo-optic dysplasia (SOD), also known as de Morsier syndrome, which is a rare congenital disorder. It is characterized by a combination of abnormalities, including optic nerve hypoplasia, pituitary dysfunction, and midline abnormalities. We present the case of a 37-year-old female patient with De Morsier syndrome, who seeks medical attention due to infertility. She presents with hypopituitarism, characterized by growth hormone deficiency and hypogonadotropic hypogonadism, diagnosed at the age of 11 in the context of short stature and delayed puberty. The patient also exhibits complications associated with these deficits, such as infertility, metabolic syndrome, and skeletal compromise. Early diagnosis and treatment can prevent morbidity and mortality associated with this syndrome, but unfortunately, infertility remains unaffected. Nevertheless, achieving pregnancy is possible through ovulation induction.

A síndrome de De Morsier, é uma doença congênita rara, caracterizada por uma combinação de alterações: hipoplasia do nervo óptico, disfunção hipofisária e anomalias da linha média. Apresentamos o caso de uma paciente de 37 anos com displasia septo-óptica (SOD), também conhecida como síndrome de De Morsier que consultou por infertilidade. Associado à SOD detectou-se hipopituitarismo, com deficiência de hormônio do crescimento e hipogonadismo hipogonadotrófico diagnosticado aos 11 anos de idade em um contexto de hipocrescimento e impuberdade. Foram observadas também complicações associadas a esses déficits como infertilidade, síndrome metabólica e envolvimento ósseo. O diagnóstico e tratamento precoces podem prevenir a morbimortalidade associada a esta síndrome, mas não a infertilidade. No entanto, a gravidez é possível através da indução da ovulação.