Cytology of collagenous spherulosis of the breast: a diagnostic dilemma – report of three cases

Collagenous spherulosis is a rare incidental finding seen in association with benign breast lesions. Cytological findings in three cases of collagenous spherulosis diagnosed on fine needle aspiration are presented. The presence of hyaline pink globules surrounded by benign myoepithelial cells in Giemsa stained smears was a diagnostic feature. Associated lesions were atypical papillary hyperplasia (2) and fibroadenoma (1). Adenoid cystic carcinoma was the close differential diagnosis on cytology. Awareness of this entity is important to avoid a false positive diagnosis of malignancy.     

Periplaneta americana midgut proteases differentially expressed against dietary components from different plant seeds

Insect midgut proteases are known to be regulated by plant protease inhibitors. In the present study, the antinutritional effects of a variety of seed extracts against Periplaneta americana (Linnaeus) (Dictyoptera: Blattidae) midgut proteases are assessed in vitro and in vivo. Bioassays are conducted by allowing P. americana to feed on diets incorporated with the tested seed extracts. Low survival rates are recorded on a diet incorporated with seed powders of Ricinus communis (10%), Glycine max (30%), Datura alba (50%) and Mucuna pruriens (50%). Proteolytic and residual proteolytic activities are highly inhibited by the four seed extracts. Electrophoretic analysis shows that the majority of P. americana midgut protease isoforms are inhibited by the four seed extracts in vivo as well as in vitro. The midgut physiology of P. americana is affected by the seed extracts of D. alba, M. pruriens and Sapindus laurifolius, by over synthesising or changing mobilities of existing protease isoforms. Furthermore, some key proteases in P. americana midgut are involved in the regulation of other protease isoforms. These results suggest that seed extracts from the above plants are potential sources of plant protease inhibitors for managing economically important crop pests.     

Effects of temperature and fertilization on nitrogen cycling and community composition of an urban lawn

We examined the influence of temperature and management practices on the nitrogen (N) cycling of turfgrass, the largest irrigated crop in the United States. We measured nitrous oxide (N₂O) fluxes, and plant and soil N content and isotopic composition with a manipulative experiment of temperature and fertilizer application. Infrared lamps were used to increase surface temperature by 3.5±1.3 °C on average and control and heated plots were split into high and low fertilizer treatments. The N₂O fluxes increased following fertilizer application and were also directly related to soil moisture. There was a positive effect of warming on N₂O fluxes. Soils in the heated plots were enriched in nitrogen isotope ratio ( δ ¹⁵N) relative to control plots, consistent with greater gaseous losses of N. For all treatments, C₄ plant C/N ratio was negatively correlated with plant δ ¹⁵N, suggesting that low leaf N was associated with the use of isotopically depleted N sources such as mineralized organic matter. A significant and unexpected result was a large, rapid increase in the proportion of C₄ plants in the heated plots relative to control plots, as measured by the carbon isotope ratio ( δ ¹³C) of total harvested aboveground biomass. The C₄ plant biomass was dominated by crabgrass, a common weed in C₃ fescue lawns. Our results suggest that an increase in temperature caused by climate change as well as the urban heat island effect may result in increases in N₂O emissions from fertilized urban lawns. In addition, warming may exacerbate weed invasions, which may require more intensive management, e.g. herbicide application, to manage species composition.     

Aspiration cytology of Hashimoto's thyroiditis in an endemic area

Fine needle aspiration (FNA) plays a significant role in the diagnosis of thyroid lesions due to its simplicity and low cost. Hashimoto's thyroiditis (HT) is the second most common thyroid lesion next to endemic goitre diagnosed on FNA in iodine (I2) deficient areas. Data on its incidence, prevalence and clinicopathological features in I2 deficient areas is scanty compared to I2 sufficient areas. In the present study the patients presented with HT a decade earlier than reported in I2 sufficient areas. Presentation as a nodular thyroid is common. Diagnosis of HT is likely to be missed in smears showing cytological evidence of hyperplasia or abundant colloid. HT was concurrent in 20 cases of endemic goitre. Careful screening for Hurthle cell change and lymphocytic infiltration into follicular cells should be carried out. In equivocal cases multiple punctures and immunological investigations are helpful. In antibody-negative cases repeat FNA at follow-up is useful. Marked lymphocytic infiltration and Hurthle cell change may indicate a hypothyroid state but hormonal levels are required for clinical management.