Ecological cues, gestation length, and birth timing in African buffalo (Syncerus caffer)

We examined annual variation in the timing of conception andparturition in the African buffalo (Syncerus caffer) and thesynchrony of birth timing with resource cues, using 8 yearsof monthly birth, rainfall, and vegetation data, measured asNormalized Difference Vegetation Index (NDVI). Monthly birthshad the strongest significant correlations with NDVI and rainfalllevels 12 and 13 months in the past, respectively. In addition,the synchrony of current year births corresponds most stronglyto the synchrony of the previous year's NDVI distribution. Becausethe gestation period of buffalo has been estimated to be around11 months, these findings suggest that improved protein levels,occurring approximately a month after the first green flushof the wet season, are either a trigger for conception or conceptionhas evolved to be synchronous with correlated environmentalcues that ensure females enter a period of peak body conditionaround the time of conception and/or parturition. With a gestationperiod of approximately 340 days, parturition occurs to takeadvantage of the period when forage has its highest proteincontent. A comparative analysis of gestation periods withinthe subfamily Bovinae indicates that African buffalo have aprotracted gestation for their body size, which we suggest isan adaptation to their seasonal environment. We also found thatinterannual variation in the birth distribution suggests a degreeof plasticity in the date of conception, and variation in thenumber of calves born each year suggest further synchrony ata timescale longer than a single year.     

Cytomorphology and marker expression of malignant neuroendocrine cells in pleural effusions

Three cases of pulmonary neuroendocrine carcinoma with malignant pleural effusions were retrospectively studied to determine if cellular morphology and expression of neuroendocrine markers were the same in the fluid as in the solid milieu. In fluids, changes were noted in cell grouping, shape and cytoplasm. Neuroendocrine markers expressed in both solid and dispersed tumors were neuron-specific enolase (NSE) in all cases and leu-enkephalin in one case. Vasoactive intestinal polypeptide (two cases) and serotonin (one case) were detected only in the solid tumor. ACTH, bombesin and calcitonin were not expressed. We tentatively conclude that, in effusions, neoplastic neuroendocrine cells may alter their cytostructure, growth patterns and marker expression capabilities. NSE appears to be the most reliable neuroendocrine marker for use in small samples and with varying preparatory methods.     

Crystallization of the ColE1 Rop protein

Preliminary crystallographic data are given for Rop, a protein involved in the control of replication of plasmids of the ColE1 family.