Temperature variation in nests of Paleosuchus palpebrosus (Crocodylia: Alligatoridae) near the southern edge of the species´ range, Brazil.

We monitored the temperature of seven Paleosuchus palpebrosus nests found on the banks of streams surrounding the Brazilian Pantanal, near the southern limit of the species´ distribution, between 2008 and 2013. The mean temperature of the nests between 45 and 68 days incubation, the presumed period of sex determination, varied between 26.1 and 31.5o C. Nest temperatures were 2 to 5°C higher than air temperatures, presumably due to metabolic heat of decay of material within the nests, but air temperature explained 10-50% of the variance in egg-chamber temperatures. The estimated incubation periods for nests from which eggs hatched were 80, 84, 86, 90 and 104 days with a mean of 89 (SD =9.23) days, though these are probably slight overestimates because eggs may have hatched in the period between inspections. For these nests, there was no significant relationship between mean temperature and incubation period (r2 = 0.23, p = 0.411).

Detecting population structure of Paleosuchus trigonatus (Alligatoridae: Caimaninae) through microsatellites markers developed by next generation sequencing.

We isolated and characterized 10 new microsatellites loci for Paleosuchus trigonatus using ION TORRENT Sequencing Technology. We tested the transferability of these loci to three related species of the subfamily Caimaninae, and used these bi-parental markers to test population structure and genetic diversity of two populations of P. trigonatus impacted by hydroelectric dam construction on the Madeira (N = 16) and Xingu (N = 16) rivers. We also investigated the transferability of these markers to three related species: Paleosuchus palpebrosus (N = 5), Caiman crocodilus (N = 6) and Melanosuchus niger (N = 6). The genetic diversity of P. trigonatus was low in both the Madeira (He: 0.535 ± 0.148) and Xingu (He: 0.381 ± 0.222) populations, but the loci were sufficiently polymorphic to be used in system of mating and kinship studies in P. trigonatus. DAPC analysis with our set of microsatellites loci was able to separate the four species of Caimaninae studied and to detect a shallow genetic structure between Madeira and Xingu populations of P. trigonatus. AMOVA and STRUCTURE analyses using locprior model corroborate this shallow genetic structure. These novel molecular markers will be also useful in conservation genetics and phylogeographic studies of P. trigonatus, since they improve our ability to monitor the putative effects of dams on the loss of genetic diversity and allow us to investigate population dynamics and microevolutionary processes that occurred in the species.

CT scans of cranial tuberculosis.

Tuberculosis of the central nervous system is still an important cause of death or significant neurologic disability. Prompt diagnosis and early treatment are extremely important to reduce its morbidity and mortality. The main forms of intracranial tuberculosis are represented by tuberculous meningitis, meningeal or parenchymal tuberculomas, and tuberculous abscess formation. Sequelae consist of hydrocephalus, calcifications, and areas of encephalomalacia. Less frequent manifestations include tuberculous osteitis of the skull and tuberculous otomastoiditis. Although MR imaging is in general somewhat more sensitive to the detection of cranial tuberculosis, CT is the diagnostic imaging mainstay in many clinical settings to demonstrate the various aspects of cranial tuberculosis on initial presentation and to monitor the evolution of the disease and response to therapy.

Irradiation of the cervix uteri: value of unenhanced and contrast-enhanced MR imaging.

PURPOSE: To analyze the value of magnetic resonance (MR) imaging after radiation therapy for cancer of the cervix. MATERIALS AND METHODS: Eighty-nine MR images were retrospectively studied in 69 patients aged 46.3 years +/- 11.5. MR findings of tumor recurrence and irradiation changes were correlated with time after radiation therapy; paracentral radiation dose (dose to point A); and in patients with pretreatment images, primary tumor size and stage. RESULTS: Overall accuracy of MR in diagnosis of tumor recurrence was 78% (positive predictive value, 65%; negative predictive value, 97%). In MR examinations less than 6 months after the beginning of radiation therapy, accuracy (69%) and specificity (46%) were significantly lower than in examinations more than 6 months later (88%, P = .0032; 81%, P = .0166, respectively). Comparison of pre- and posttreatment MR findings and knowledge of stage or initial tumor size did not affect MR results. CONCLUSION: Overall, diagnosis was best with unenhanced T2-weighted images, but in patients with adnexal or pelvic sidewall recurrence and in patients with treatment complications (eg, fistula formation), contrast enhancement did help.

Carcinoma of the cervix: predictive value of clinical and magnetic resonance (MR) imaging assessment of prognostic factors.

PURPOSE: This retrospective study assesses the predictive value of magnetic resonance imaging (MRI) to identify high risk cervical cancer patients. METHODS AND MATERIALS: The MRI evaluation of morphologic risk factors in patients with invasive cervical carcinoma treated with definitive radiation therapy were correlated with clinical factors and with complete tumor regression (CTR) at 6 months, tumor local control (TLC), and patient outcome at 12 months after irradiation. Sixty-six patients, median age 44.5 years, with bulky Stage I or greater disease were included in the study. RESULTS: In univariate analysis, clinical International Federation of Gynecology and Obstetrics (FIGO) stage had significant correlation with patient outcome, but it correlated poorly with complete tumor regression and tumor local control. In contrast, MRI stage showed significant correlation with complete tumor regression, tumor local control, and disease-free survival at 12 months. When each stage was analyzed separately, the greatest difference was demonstrated between clinical and MRI assignment of stage Ib disease. MRI Stage Ib disease significantly correlated with all three categories analyzed, while clinical Stage Ib did not. Superiority of MRI assessment of low stage disease was also evident in the detection of lymph node metastasis. Significant risk for nodal metastasis was related to tumor size greater than 4 cm, invasion of the parametria and urinary bladder, and stage of the disease. CONCLUSION: The multivariate analysis demonstrated that the most related variables in order of significance were the presence of juxta-regional and paraaortic lymph nodes, patient age, tumor size, and MRI tumor stage. This study demonstrates the value of MR imaging as an adjunct to clinical assessment of bulky invasive cervical cancer, rendering more complete assessment of morphologic risk factors important in patient prognosis.

Relationships between cell surface protease and acid phosphatase activities of Leishmania promastigote.

A correlation between the ratio of the cell surface protease activity to phosphatase activity and the complexity of the pattern of cell surface exposed polypeptides of Leishmania promastigotes was demonstrated for various strains grown under similar conditions. The ratio of the cell surface protease activity to acid phosphatase activity was high for L. major and L.b. panamensis and it correlates with the expression of a single polypeptide of 63 KDa on their cell surface. Intermediate and lower ratios of these enzymatic activities relate with more complex radio-iodinated patterns: two main bands in L.b. guyanensis (70 and 58 KDa) and L.b. braziliensis (72 and 60 KDa) and three main bands 65, 50, 27 KDa in all L.m. mexicana strains tested. Evidence is presented that the acid phosphatase located on the L.m. mexicana cell surface is not an artifact due to a secondary absorption of the secreted acid phosphatase from the culture medium. These results confirm the Leishmania antigen cell surface heterogeneity. The implications on the biology of Leishmania and the clinical manifestation of leishmaniasis are discussed.

Teratomas versus cystic hemorrhagic adnexal lesions: differentiation with proton-selective fat-saturation MR imaging.

To assess the value of proton-selective fat-saturation magnetic resonance (MR) imaging in differentiating teratomas from cystic hemorrhagic masses, 38 patients with 48 lesions (21 teratomas, 27 cystic hemorrhagic masses) detected at prior ultrasound or computed tomography were imaged with standard T1- and T2-weighted spin-echo (SE) sequences. Twenty-one patients with 28 lesions (13 teratomas, 15 cystic hemorrhagic masses) were imaged with an additional T1-weighted fat-saturation sequence. On standard T1- and T2-weighted SE images, 43% of the teratomas and 52% of the cystic hemorrhagic masses were characterized correctly with signal intensity criteria. Sixty-two percent of the teratomas and 100% of the cystic hemorrhagic masses were characterized correctly with chemical shift artifact criteria. With fat-saturation images alone, the characterization sensitivity for teratomas and cystic hemorrhagic masses increased to 92% and 100%, respectively. Fat-saturation MR imaging was statistically superior to standard T1- and T2-weighted imaging in characterizing teratomas.

MRI and ultrasound detection of asymptomatic thyroid nodules in hyperparathyroidism.

A retrospective MRI and ultrasound (US) study of 50 patients with hyperparathyroidism and no history of thyroid disease was done. The purpose was to compare the sensitivity of both methods in the detection of asymptomatic thyroid nodules, as well as to determine the prevalence of thyroid abnormalities in patients with hyperparathyroidism. All the patients underwent MR and 33 were also studied by high-resolution US. Magnetic resonance imaging was performed on a 1.5 T unit, using T1-(500-700/20) and T2-(2,000/20 and 70) weighted images. Axial sections (5 mm with a 1 mm interval between them) were obtained along the neck. Ultrasonography was performed using a 10 MHz linear array transducer. The prevalence of thyroid nodules was 46% in the 50 patients studied by MR imaging. In the subgroup of patients studied by both methods, US depicted nodules in 48% of patients, and MR depicted nodules in 45%. Magnetic resonance imaging and US detected a high frequency of thyroid nodules in patients with hyperparathyroidism. This high frequency makes the detection of an intrathyroidal parathyroid adenoma problematic.

[Mibelli's porokeratosis and basaloid epithelioma]. / Poroceratose de Mibelli e epitelioma basalióide.

A case of basal cell epithelioma associated with porokeratosis is reported. The existence of others publications about porokeratosis and cutaneous cancer confirms the malignant potential of this genodermatosis . The danger of radiotherapy and overexposure to sunlight in this condition is emphasized.