Dormancy induction by summer temperatures and/or desiccation in imbibed seeds of trumpet daffodils Narcissus alcaracensis and N. longispathus (Amaryllidaceae).

We analysed the effects of summer temperatures (28/14 °C) and/or desiccation (from 48% to 8% humidity) on imbibed Narcissus alcaracensis and N. longispathus seeds with an elongating embryo. In the N. alcaracensis seeds that overcame dormancy (embryo elongation = 27.14%), exposure to high temperatures induced secondary dormancy and reduced subsequent embryo growth. A further 3-month cold stratification (5 °C) was required to break secondary dormancy. Desiccation in early embryo growth stages (elongation = 11.42%) also reduced germination. Desiccation in the seeds in a more advanced growth stage (i.e. embryo elongation = 27.14%) induced secondary dormancy, which the further 3-month cold stratification did not overcome. When desiccation was preceded by high temperatures, seeds better overcame secondary dormancy (i.e. longer embryo elongation and seed germination). Treatments did not affect seed viability. In the N. longispathus seeds that overcame dormancy (embryo elongation = 59.21%), exposure to high temperatures induced secondary dormancy and they needed a further 1-month stratification at 15/4 °C + 2 months at 5 °C to reactivate the germination process. When embryo elongation was 42.10%, seed desiccation totally impeded subsequent germination. When embryo elongation reached 59.21%, desiccation induced secondary dormancy, which was not overcome by the above-described stratification treatment. When desiccation was preceded by high temperatures, seeds better overcame dormancy. Stress treatments killed 5-10% of seeds. This study suggests that the seeds of species with complex morphophysiological dormancy (MPD) levels are sensitive to desiccation in early embryo development stages, as opposed to the seeds of species with deep simple epicotyl MPD, which better tolerate water stress.

Annual dormancy cycles in buried seeds of shrub species: germination ecology of Sideritis serrata (Labiatae).

The germination ecology of Sideritis serrata was investigated in order to improve ex-situ propagation techniques and management of their habitat. Specifically, we analysed: (i) influence of temperature, light conditions and seed age on germination patterns; (ii) phenology of germination; (iii) germinative response of buried seeds to seasonal temperature changes; (iv) temperature requirements for induction and breaking of secondary dormancy; (v) ability to form persistent soil seed banks; and (vi) seed bank dynamics. Freshly matured seeds showed conditional physiological dormancy, germinating at low and cool temperatures but not at high ones (28/14 and 32/18 °C). Germination ability increased with time of dry storage, suggesting the existence of non-deep physiological dormancy. Under unheated shade-house conditions, germination was concentrated in the first autumn. S. serrata seeds buried and exposed to natural seasonal temperature variations in the shade-house, exhibited an annual conditional dormancy/non-dormancy cycle, coming out of conditional dormancy in summer and re-entering it in winter. Non-dormant seeds were clearly induced into dormancy when stratified at 5 or 15/4 °C for 8 weeks. Dormant seeds, stratified at 28/14 or 32/18 °C for 16 weeks, became non-dormant if they were subsequently incubated over a temperature range from 15/4 to 32/18 °C. S. serrata is able to form small persistent soil seed banks. The maximum seed life span in the soil was 4 years, decreasing with burial depth. This is the second report of an annual conditional dormancy/non-dormancy cycle in seeds of shrub species.

[Varices in the round ligament]. / Varices en el ligamento redondo.

Varices in the round ligament are very rare and have only been reported in pregnant women as an inguinal mass normally detected in the third trimester of gestation. B-mode and Doppler color ultrasonography are fundamental tools in the diagnosis, because they make it possible to reach a conclusive diagnosis and to rule out other clinically possible inguinal masses. Given that the treatment is conservative, it is essential for the radiologist to be familiar with this condition and its ultrasonographic characteristics to enable the correct diagnosis and avoid unnecessary surgical exploration.

Large granular lymphocyte leukemia and its association with oral neutropenic ulcerations: a case report.

Large granular lymphocyte leukemia is a rare chronic indolent disorder commonly associated with severe neutropenia. The pathogenesis of the neutropenia is unclear. A case is presented of a 74-year-old man who had recurrent oral ulcerations for over a year before a diagnosis was made. These recurrent oral ulcers cleared with treatment and have not returned. The differential diagnosis of persistent oral ulcerations includes trauma; viral, fungal, and bacterial infections; systemic disease; or various malignant conditions. The oral ulcers in this man were likely infectious in nature and related to the severe chronic neutropenia. This case serves to illustrate the potentially complex nature of oral ulcers.

Solitary bone cyst of the jaws: radiographic review of 44 cases.

Solitary bone cyst is a radiolucent lesion classified as a pseudocyst with a variety of reported shapes including round, oval, and irregular. In the long bones, a truncated cone shape has been described, and the fallen trabecula sign is seen in association with pathologic fracture. The purpose of this study was to classify and document the various shapes, to describe the width versus height dimensions of jaw SBCs, to determine the identifying signs of trauma, and to evaluate other reported radiographic features. Radiographs of 44 SBCs in 43 patients were studied. Sixty-four percent demonstrated the cone shape, and four subtypes of this shape were identified. Other shapes included oval (16%), irregular (16%), and round (4%). Radiographic signs of trauma were observed in 28% of the cases. No evidence of the "fallen trabecula sign" was found in this series.

Expression of p53, Ki-67 and cytokeratin-4 (CK4) in oral papillomas.

P53 is overexpressed in more than 50% of all human cancers. A previous study suggested that p53 was also overexpressed in oral papillomas. This study was carried out to investigate whether p53 expression was correlated with expression of the cellular proliferation marker Ki-67 and the epithelial differentiation marker cytokeratin-4 (CK4) in oral papillomas. Formalin-fixed paraffin-embedded sections of 30 oral papilloma specimens and 30 unmatched normal oral mucosal specimens were processed for immunohistochemistry, using an avidin-biotin-peroxidase procedure and monoclonal antibodies. A semiquantification analysis on p53 and Ki-67 labeling indices was performed. Twenty-eight of 30 (93%) papilloma specimens were positive for p53. The percentage of p53-positive cells in the basal layer was 60.4 +/- 14.8 (mean +/- SD, n = 28), and that of Ki-67-positive cells was 26.7 +/- 14.4. There was no correlation between expression of p53 and that of Ki-67. Expression of CK4 was inversely correlated with the expression of Ki-67 but not correlated with the expression of p53.

Squamous carcinoma arising from a dentigerous cyst: report of a case.

A case of squamous carcinoma arising in the lining of a dentigerous cyst is presented. This case is interesting because, clinically and radiographically, the diagnosis was unexpected. The light-microscopy examination revealed the moderately well-differentiated squamous carcinoma. The presentations of the case are discussed.