The aim of the present study was to determine the number of cone classes in the Xenopus retina. We examined the dimensions and staining properties of cones, utilizing two monoclonal antibodies, COS-1 and OS-2, developed by Szel and Rohlich (1985). Living cones also were reacted with the plant lectins peanut agglutinin (PNA) and wheat germ agglutinin (WGA) and with a fluorescent stilbene dye, DIDS, which binds selectively to red-sensitive cones (Kleinschmidt, 1991; Kleinschmidt & Harosi, 1992a, b). Three cone populations were distinguished based on differences in size and staining properties. Eighty-eight percent of all cones were stained strongly by COS-1, PNA, and DIDS, but weakly by OS-2. The group of cones stained by COS-1 had the largest mean dimensions of outer segment length, width, and oil droplet diameter. COS-1 negative cones were divisible into two groups: a subclass of miniature cones (approximately 4% total cones) was stained strongly by OS-2, PNA, and DIDS. The balance, constituting approximately 9% total cones, were of intermediate size, were not stained by PNA and reacted weakly to OS-2 and DIDS. WGA stained all cones. Large, COS-1 + cones appear to be red-sensitive and belong to the class of anion-tunable cone pigments. We suggest that the intermediate size, COS-1 negative cones are blue-sensitive based on the finding that blue-sensitive chromatic horizontal cells connect to them preferentially (Witkovsky et al., work in progress). The remaining class of miniature cones may be UV-sensitive, since another amphibian, the salamander, has been shown to possess red-, blue-, and UV-sensitive cones (Perry & McNaughton, 1991).

We compared the overall ASC rate and the outcomes for women with different categories of ASC before and after TBS 2001 to evaluate the impact of TBS 2001. Our laboratory reported ASC in four subcategories before TBS 2001; ASC, favor reactive (ASC-R), favor low-grade squamous intraepithelial lesion (SIL) (ASC-L), undetermined significance (ASC-US), and ASC-H. Since the implementation of TBS 2001, we have been reporting ASC as ASC-US and ASC-H. After TBS 2001, our ASC rate decreased from 6.2% to 4% (P < 0.0001). Before TBS 2001, ASC-R carried the same risk as ASC-US for underlying condyloma/CIN 1. Moreover, ASC-R was rarely associated with CIN 2 or 3. Before TBS 2001, ASC-H captured more low-grade (condyloma/CIN 1) and less high-grade (CIN 2, 3, and SCC) lesions compared to after TBS 2001. More women with ASC-H after TBS 2001 underwent colposcopy (80% vs. 71%, P < 0.05). Twenty-two percent of women with ASC-H required 2-4 colposcopies to identify the high-grade lesion. Our results confirm that consistent application of TBS 2001 terminology for ASC reduces the ASC rate, and better identifies women at high risk for CIN 2, 3, and SCC. In addition, ASC-H requires very close clinical follow-up as a significant percentage of women require more than one colposcopy to identify the high-grade lesion.

The Bethesda system separates atypical reparative changes (ARC) from "typical" repair and places it into the atypical squamous cells of undetermined significance (ASC-US) category. The cytologic diagnosis of ARC represents both diagnostic and management challenges because its clinical significance is controversial and has not been fully investigated. On the basis of scant literature on follow-up of women with ARC on Papanicolaou (Pap) test, we reviewed data from our patient population, which consists of a mixture of low- and high-risk women. Six hundred forty-seven patients with ARC on their Pap tests were identified in a 7-yr period. Of this, 189 (29%) women were lost to follow-up. Of the 458 women with follow-up, 31% had cervical biopsies and 69% were followed by repeated Pap tests. The age ranged from 16 to 86 (mean 47 yr). The incidence of squamous intraepithelial lesion was 5.2% (5% low-grade and 0.2% high-grade). Most women (62%) with ARC on Pap test had a benign condition on follow-up. For some women, the immediate cause was not known and the Pap abnormality resolved spontaneously. Our study questions the validity of reporting ARC within the ASC-US category.