Tissues undergoing rapid growth and regeneration contain hyaluronic acid (HA) as a prominent component of the extracellular matrix. The physiologic role of HA is partly mediated by its relationship with CD44, its major cell surface receptor. Given the extensive remodeling of the endometrium during the menstrual cycle, the authors sought to determine whether these changes are related to the levels of HA, CD44s, and CD44v6 in the endometrium. Archival paraffin embedded cell blocks from 10 cases of proliferative endometrium and 20 cases of secretory endometrium were retrieved from the surgical pathology files. Specimens from the secretory phase were subdivided into three categories: early secretory (day 15-18), mid-secretory (day 19-23), and late secretory (day 24-28). All cases were stained for hyaluronic acid, CD44s, and CD44v6. Sections from umbilical cord, tonsil, and squamous cell carcinoma served as positive controls for HA, CD44s, and CD44v6, respectively. Positive staining was defined as droplet to diffuse intracytoplasmic or extracellular staining for HA and uniform membranous staining for CD44. During the proliferative phase, the endometrial glands and the stroma were both negative for CD44s and CD44v6 in all cases. In the secretory phase, the endometrial glands were negative for CD44s in all cases, but CD44v6 was expressed in 12 (60%) of cases. In contrast, the stromal cells expressed CD44s in 18 (90%) cases and were negative for CD44v6 in all cases. HA staining was present in the endometrial stroma throughout the menstrual cycle but was most intense (3+) and diffuse during the midsecretory phase. There was perivascular staining for HA throughout the cycle; it was most intense adjacent to the spiral arterioles in the secretory phase. These data indicate temporal and geographic differences in HA and CD44 staining in the endometrium in concert with the menstrual cycle. The timing of peak staining of HA and CD44s in the stroma and the upregulation of CD44v6 in secretory glands are coincident with the period in which the endometrium is most receptive to embryo implantation. Whether these changes are mere hormonal consequences or actually help modulate the cyclical changes in the endometrium warrants further study.

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The conjunctival microcirculation in 14 pediatric and eight adult sickle cell anemia (SCA) patients was studied using computer‐assisted intravital microscopy. The bulbar conjunctiva in SCA patients in both age groups exhibited a blanched/avascular appearance characterized by decreased vascularity. SCA patients from both age groups had many of the same abnormal morphometric [vessel diameter, vessel distribution, morphometry (shape), tortuosity, arteriole:venule (A:V) ratio, and hemosiderin deposits] and dynamic [vessel sludging/sludged flow, boxcar blood (trickled) flow, and abnormal flow velocity] abnormalities. A severity index (SI) was computed to quantify the degree of vasculopathy for comparison between groups. The severity of vasculopathy differed significantly between the pediatric and adult patients (SI: 4.2 ± 1.8 vs. 6.6 ± 2.4; P = 0.028), indicative of a lesser degree of overall severity in the pediatric patients. Specific abnormalities that were less prominent in the pediatric patients included abnormal vessel morphometry and tortuosity. Sludged flow, abnormal vessel distribution, abnormal A:V ratio, and boxcar flow appeared in high prevalence in both age groups. The results indicate that SCA microvascular abnormalities develop in childhood and the severity of vasculopathy likely progresses with age. Intervention and effective treatment/management modalities should target pediatric patients to ameliorate, slow down, or prevent progressive microvascular deterioration. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.

Increased serum C-reactive protein and S100A12 concentrations were observed in a subpopulation of dogs with various types of hepatic diseases, suggesting acute-phase inflammation and activation of phagocytic cells, respectively. Dogs with higher hepatic necroinflammatory activity scores tended to have higher serum C-reactive protein concentrations. Further studies are needed to confirm this finding in a larger group of dogs.