High yield synthesis, purification and characterisation of the RNase L activators 5'-triphosphate 2'-5'-oligoadenylates.

Upon viral infection, double-stranded viral RNA is detected very early in the host cell by several cellular 2'-5' oligoadenylate synthetases, which synthesize 2'-5' adenylate oligonucleotides that activate the cellular RNase L, firing an early primary antiviral response through self and non-self RNA cleavage. Transfecting cells with synthetic 2'-5' adenylate oligonucleotides activate RNase L, and thus provide a useful shortcut to study the early steps of cellular and viral commitments into this pathway. Defined 2'-5' adenylate oligonucleotides can be produced in vitro, but their controlled synthesis, purification, and characterisation have not been reported in detail. Here, we report a method suitable to produce large amounts of 2-5As of defined lengths in vitro using porcine OAS1 (pOAS) and human OAS2 (hOAS). We have synthesized a broad spectrum of 2-5As at the milligram scale and report an HPLC-purification and characterisation protocol with quantified yield for 2-5A of various lengths.

Chronic lymphocytic (Hashimoto's) thyroiditis in Kuwait diagnosed by fine needle aspirates.

A retrospective analysis of 4185 consecutive fine needle aspirates (FNA) of the thyroid over an eight year period at a teaching hospital in Kuwait revealed that 14.3% of all the aspirates had features of chronic lymphocytic (Hashimoto's) thyroiditis (HT). The proportion of patients with HT showed a slight increase in the last two years but the pattern of clinical presentation has remained unchanged. Hashimoto's thyroiditis was most prevalent in the age group from 16 to 35 and the majority of young patients with Hashimoto's thyroiditis presented with diffuse goiter (DG) whereas multinodular goiter (MNG) and solitary thyroid nodule (STN) were more common in the older age group. Of patients who presented with STN, the most common abnormality on thyroid scan was a "cold nodule". Functional disturbances (hypo and hyperthyroidism) occurred less frequently in patients presenting as STN than in patients presenting with DG or MNG. We conclude that FNA is indicated in all young patients with diffuse goiter in this region in order to facilitate early detection and initiation of suppressive thyroxine therapy. Further, when young patients present with "cold" solitary nodules of the thyroid, HT is a more common cause than a thyroid carcinoma in Kuwait.

Fine needle aspiration cytologic diagnosis of axillary accessory breast tissue, including its physiologic changes and pathologic lesions.

Sixty-nine cases of axillary accessory breast tissue, including its physiologic changes and pathologic lesions, were diagnosed by fine needle aspiration cytology. The age of the patients ranged from 13 to 40 years, with a median of 25, and all were female. The cases presented with swellings in the left axilla in 16 cases, right axilla in 30 cases and both axillae in 23 cases. The common clinical diagnoses included accessory breast tissue (23.2%), lipomatous lesion (17.4%), lymphadenopathy (18.8%) and swellings not otherwise specified (30.4%). In 8.8% cases two of the possibilities were considered. The cytodiagnoses included axillary accessory breast tissue (47 cases), axillary breast tissue with pregnancy or lactational changes (15), cystic disease (4) and fibroadenoma (3). One of the cystic disease cases showed granulomatous inflammation. Although no case of carcinoma in axillary breast tissue was diagnosed during the study period, there were two cases of malignancy in axillary swellings (diagnosed as metastatic carcinoma) when no primary was detected in the breasts.

Acrobatic ears: a cause of petrified auricles.

Calcified ear cartilages are rarely encountered and only 12 histologically proven cases have been documented. The case presented is of ossified auricles in a teenager and has many interesting features. Acrobatic manipulation of the auricles as a cause of the lesion was one of the distinguishing features.