Necrotizing perineal fasciitis in two paraplegic nursing-home residents: CT imaging findings.

Necrotizing fasciitis is a severe infection of the superficial fascia. Early recognition and aggressive management are essential to the treatment of this highly morbid disease. The clinical and physical findings are often the initial clues leading to the correct diagnosis. Computed tomography can play a crucial role in delineating the anatomy, evaluating for the extent of the infection, and for eventual complications. Before the advent of cross-sectional imaging, the majority of suspected patients underwent extensive surgical debridement procedures with resultant morbidity and mortality. We present two cases in which computed tomography played a major role in determining the need for emergent surgery and conservative management.

Systemic mastocytosis with involvement of the pelvis: a radiographic and clinicopathologic study--a case report.

The musculoskeletal manifestations of systemic mastocytosis have been described in the literature. We present a case of systemic mastocytosis involving the pelvis. Conventional radiographs and CT imaging may demonstrate diffuse sclerotic, or mixed lytic and sclerotic lesions. On MRI, the lesions, if sclerotic, may show low signal on T1- and T2-weighted images. However, if lytic, the lesions may demonstrate low signal on T1, and increased signal on T2. As there are numerous disease entities included within the differential diagnosis, the clinical and pathological findings are crucial for establishing the correct diagnosis.

CT diagnosis of acquired intercostal lung herniation.

Intercostal lung herniation is a rare complication of trauma, best demonstrated by computed tomography. Most intercostal lung herniations are the result of direct trauma to the chest wall or occur at sites of prior percutaneously placed chest tubes. We present two cases of acquired intercostal lung herniation.

Androgen-uterine interaction: nuclear translocation of the estrogen receptor and induction of the synthesis of the uterine-induced protein (IP) by high concentrations of androgens in vitro but not in vivo.

High concentrations of androgens in vitro [10(-6) and 10(-7)M 5alpha-dihydrotestosterone (DHT) and testosterone (T)] translocate the estrogen receptor from cytoplasmic to the nuclear fraction of the immature rat uterus, and the androgen translocated sites are capable of eliciting the synthesis of the specific uterine "induced protein" (IP), formerly attributed to estrogenic compounds only. The magnitude of receptor translocation and IP synthesis induction is related to the concentration of androgen, and, at equal concentrations, DHT is more effective than T. Competitive protein-binding asssays with cell-free uterine cytosol indicate that DHT and T bind with barely detectable affinity to the cytosol estrogen receptor detectable affinity to the cytosol estrogen receptor [relative binding ability ca. 0.001% that of estradiol (E2)], and radioactive E2 uptake into whole uterus after pretreatment with androgens indicates that the androgen-translocated nuclear sites are readily filled by E2. DHT and T translocate the estrogen receptor to the nucleus in vitro, and the salt-extracted nuclear receptor is present as a 5 S ("transformed") receptor; however, concentrations of DHT and T that effect translocation are unable to elicit the heat-activated transformation of the estrogen receptor in cell free cytosol under conditions in which low concentrations of E2 fully transform the receptor. Under in vivo conditions, high levels of androgens (5--2,000 mug DHT or T) do not evoke any detectable translocation of the estrogen receptor and do not elicit any IP synthesis induction although uterine weight is increased (greater than 200 mug androgen) in long-term (2--3 day) assays. The analysis of androgen uptake and metabolism indicates that 500 mug or higher doses of DHT or T in vivo result in uterine concentrations of unmetabolized DHT or T equal to those seen after exposure to 5 X 10(-7) - 1 X 10(-6)M DHT or T in vitro. Hence, under conditions where in vivo and in vitro tissue uptake of androgen is equivalent, in vivo androgens are unable to affect the estrogen receptor system as is seen in vitro. These studies indicate that the in vitro and in vivo effects of androgens on the uterus are clearly different and suggest that the actions of androgens on the uterus in vivo are probably not directly mediated through the estrogen receptor system.