Fabrication and characterization of large numerical aperture, high-resolution optical fiber bundles based on high-contrast pairs of soft glasses for fluorescence imaging.

Fabrication and characterization of flexible optical fiber bundles (FBs) with in-house synthesized high-index and low-index thermally matched glasses are presented. The FBs composed of around 15000 single-core fibers with pixel sizes between 1.1 and 10 µm are fabricated using the stack-and-draw technique from sets of thermally matched zirconium-silicate ZR3, borosilicate SK222, sodium-silicate K209, and F2 glasses. With high refractive index contrast pair of glasses ZR3/SK222 and K209/F2, FBs with numerical apertures (NAs) of 0.53 and 0.59 are obtained, respectively. Among the studied glass materials, ZR3, SK222, and K209 are in-house synthesized, while F2 is commercially acquired. Seven different FBs with varying pixel sizes and bundle diameters are characterized. Brightfield imaging of a micro-ruler and a Convallaria majalis sample and fluorescence imaging of a dye-stained paper tissue and a cirrhotic mice liver tissue are demonstrated using these FBs, demonstrating their good potential for microendoscopic imaging. Brightfield and fluorescence imaging performance of the studied FBs are compared. For both sets of glass compositions, good imaging performance is observed for FBs, with core diameter and core-to-core distance values larger than 1.6 µm and 2.3 µm, respectively. FBs fabricated with K209/F2 glass pairs revealed better performance in fluorescence imaging due to their higher NA of 0.59.

A case of recurrent pancreatitis due to hyperlipidemia misdiagnosed as familial Mediterranean fever.

Familial Mediterranean fever (FMF) is prevalent among Arabic, Turkish, Armenian, and Jewish people and it must always be considered in the differential diagnosis of patients from these ethnic groups presenting with recurrent abdominal pain with fever. In cases of fever and recurrent abdominal pain, acute pancreatitis is an important clinical condition, which should be considered in the differential diagnosis. Serum amylase concentration in acute pancreatitis is usually more than three times the upper limit of normal. However, in recurrent pancreatitis secondary to hypertriglyceridemia, serum amylase levels, for reasons that are not well understood, may be normal or mildly elevated. Recurrent pancreatitis secondary to hypertriglyceridemia may thus pose a problem in the differential diagnosis and may lead to an erroneous diagnosis of FMF. Measurement of serum triglyceride along with amylase levels should be required for a suspected diagnosis. Computerized examination of the abdomen may need to be undertaken to exclude acute pancreatitis in the presence of hypertriglyceridemia since serum amylase levels may be normal or slightly elevated.

Tubular CD44 expression in renal allograft biopsies.

CD44 is a type I transmembrane glycoprotein serving as a cell adhesion receptor, whose main ligand is hyaluronic acid, but also may interact with collagen, laminin, fibronectin, and osteopontin. This marker is involved in cell migration, homing, activation, metastasis, and inflammation. Tubular CD44 expression has been shown to correlate with scarring in renal diseases, but there is little data on allograft biopsies. This deficiency is important since experimental studies have shown that blockade of the CD44-hyaluronic acid interaction may prolong allograft survival. In an attempt to clarify the role of tubular CD44 expression in renal allografts, CD44 expression was determined immunohistochemically in 37 allograft and 10 implantation biopsies, as the percentage of tubules expressing this marker. For implantation biopsies the mean tubular CD44 expression was 6% +/- 14%; for allograft biopsies, 13% +/- 20% (P =.17, Mann-Whitney U). By the Spearman correlation test, CD44 expression did not correlate with Banff scores, but was moderately correlated with serum creatinine values at the time of biopsy (P =.017, r =.4). These findings suggest an important role of tubular CD44 expression in renal allografts. It appears to be induced by more than one pathway, resulting in a pattern of expression that correlated with renal function. However larger series are required before recommending the routine use of this marker.