Cocaine sensitization is a marker for some facets of addiction, is greater in female rats, and may be influenced by their sex hormones. We compared the modulatory effects of endogenous or exogenous estradiol and progesterone on cocaine-induced behavioral sensitization in 106 female rats. Ovariectomized female rats received progesterone (0.5 mg/mL), estradiol (0.05 mg/mL), progesterone plus estradiol, or the oil vehicle. Sham-operated control females received oil. Control and acute subgroups received injections of saline, while the repeated group received cocaine (15 mg/kg, ip) for 8 days. After 10 days, the acute and repeated groups received a challenge dose of cocaine, after which locomotion and stereotypy were monitored. The estrous cycle phase was evaluated and blood was collected to verify hormone levels. Repeated cocaine treatment induced overall behavioral sensitization in female rats, with increased locomotion and stereotypies. In detailed analysis, ovariectomized rats showed no locomotor sensitization; however, the sensitization of stereotypies was maintained. Only females with endogenous estradiol and progesterone demonstrated increased locomotor activity after cocaine challenge. Estradiol replacement enhanced stereotyped behaviors after repeated cocaine administration. Cocaine sensitization of stereotyped behaviors in female rats was reduced after progesterone replacement, either alone or concomitant with estradiol. The behavioral responses (locomotion and stereotypy) to cocaine were affected differently, depending on whether the female hormones were of an endogenous or exogenous origin. Therefore, hormonal cycling appears to be an important factor in the sensitization of females. Although estradiol increases the risk of cocaine sensitization, progesterone warrants further study as a pharmacological treatment in the prevention of psychostimulant abuse.

OBJETIVO: O diagnóstico de osteomielite crônica em atividade ou sobreposta a outras patologias é difícil, pois estas situações mascaram os achados radiológicos de infecção. A especificidade da cintilografia do esqueleto ou com gálio-67 também é reduzida pela influência da remodelação óssea na captação destes radiofármacos. Anticorpos policlonais marcados com tecnécio-99m (Tc-99m-IgG) apresentam captação independente do metabolismo ósseo, sendo um dos radiofármacos em investigação para avaliação mais específica de infecção. CASUÍSTICA E MÉTODO: Neste estudo comparou-se a cintilografia com Tc-99m-IgG, cintilografia óssea trifásica e cintilografia com gálio-67 no diagnóstico da osteomielite crônica em atividade em 23 segmentos ósseos; correlacionando-as com dados clínico-laboratoriais e radiológicos. RESULTADOS: Oito dos 23 segmentos foram classificados como infectados, 11 não infectados e quatro inconclusivos. A sensibilidade e especificidade encontradas para cintilografia óssea, com gálio-67 e com Tc-99m-IgG foram, respectivamente, 88 e 36%, 75 e 73%, 88 e 82%. CONCLUSÃO: Os resultados sugerem que a Tc-99m-IgG possa ser utilizada no diagnóstico da osteomielite crônica em atividade.

BACKGROUND: Active chronic osteomyelitis or complicating osteomyelitis are difficult to be diagnosed by radiological imaging modalities, such as plain radiograph and CT. They frequently cause increased bone remodeling, leading to nonspecific uptake of Tc-99m-bone scan agents and gallium-67. New radiopharmaceuticals with greater infection avidity are being developed, including the nonspecific polyclonal immunoglobulin (IgG) labeled with technetium-99m. Tc-99m-IgG may be available as a ready to use kit, with no reported side effects, low patient absorbed radiation dose and low cost. MATERIAL AND METHODS: 23 bone segments with suspected active chronic osteomyelitis or violated bone osteomyelitis were studied by Tc-99m-IgG scintigraphy. All patients underwent standard three-phase bone scintigraphy using methylene diphosphonate (Tc-99m-MDP), gallium-67 scintigraphy and plain radiographs, compared with clinical evaluation and laboratory tests values. RESULTS: Infection was found in 8 sites. Sensitivity and specificity for Tc-99m-MDP, gallium-67 and Tc-99m-IgG scintigraphy were, respectively, 88 and 36%, 75 and 73%, 88 and 82%. CONCLUSION: Tc-99m-IgG may be usefull in the scintigraphic evaluation of osteomyelitis.

Symptomatic involvement of the gastrointestinal (GI) tract as a prominent symptom in Langerhans' cell histiocytosis (LCH) is uncommon, occurring in less than 1 to 5% of all cases, even when the disease is in its disseminated form. Up to now, there have been reports of 18 cases of LCH with GI manifestations, including our 2 cases, with diarrhea (77.7%), protein-losing enteropathy (33.3%) and bloody stool being the most frequent findings. The authors present two patients with severe diarrhea and refractory hypoalbuminemia, and with the protein-losing enteropathy documented by Cr51-labeled albumin studies. A review of the literature indicated that the presence of GI symptoms is often associated with systemic disease as well as with poor prognosis, mainly under 2 years of age. Radioisotopes are useful for documenting protein loss in several diseases with high specificity and sensitivity, and their utilization in the cases reviewed here permitted diagnoses in 6 children, as well as improved therapeutic management.