AutoPap system performance in screening for low prevalence and small cell abnormalities.

OBJECTIVE: To summarize the design principles of the AutoPap System evaluation score by evaluating slides having a low prevalence of abnormal cells and small cell abnormalities and assessing the evaluation score as a diagnostic tool. STUDY DESIGN: Data from two clinical studies conducted using the AutoPap System and data obtained from the evaluation score training slides were analyzed to demonstrate the effectiveness of the evaluation score. The clinical studies included a prospective, intended-use study involving approximately 13,000 slides and a comprehensive sensitivity study using approximately 1,200 slides from five laboratories. The evaluation score training set consisted of 4,174 slides from 10 laboratories. RESULTS: The robust design of the AutoPap evaluation score was demonstrated by similar detection capabilities and sensitivities to slides having either a low or high prevalence of abnormal cells. No significant difference in performance was detected between the small cell slides and the comparison groups of carcinoma in situ and invasive squamous carcinoma having normal-sized abnormal cells. In addition, the evaluation scores corresponded well to the diagnostic severity of the slides.

Retarded development of castration cells after adrenalectomy or sham adrenalectomy.

Castration produces hypertrophy of gonadotropes, stimulates a shift in storage patterns to cells that store LH and FSH together, and results in a significant rise in serum LH and FSH within 12 h. Adrenalectomy retards and attenuates this postcastration rise for 24 h (1, 2). In this study, we examined the effect of adrenalectomy on castration cell morphological development. The increased percentages of LH and FSH cells that are seen normally 24 h after castration were not seen if adrenalectomy or sham adrenalectomy was performed simultaneously. In fact, the percentages of LH cells were below control values. The expansion in the average area of LH and FSH cells was also retarded after simultaneous castration and adrenalectomy or sham adrenalectomy. The corticotrope population responded as expected to adrenalectomy and the surgical stress of castration, with an increase in the percentage and area of stained cells as well as partial degranulation. The serial sections showed no ACTH staining in gonadotropes after any of the surgical treatments. The gonadotropic storage patterns were altered, however. In castrated rats exposed to simultaneous adrenalectomy or sham adrenalectomy, the percentage of LH/FSH cells was reduced from 70% of gonadotropes in intact rats to 30%. Over 60% of the serially sectioned gonadotropes stored only one hormone, and these monohormonal cells tended to occur in clusters. Our experiments thus show that the gonadotropin storage pattern can be shifted with experimental manipulation. This may also reflect shifts in the site of hormone storage within a given cell. We suggest that adrenalectomy or sham adrenalectomy retards the postcastration rise in gonadotropins by preventing the immediate expansion of the granulated cell population and causing an apparent loss in the numbers of certain types of gonadotropes.

Storage of anterior lobe adrenocorticotropin in corticotropes and a subpopulation of gonadotropes during the stress-nonresponsive period in the neonatal male rat.

The neonatal rat exhibits a stress-nonresponsive period during days 4-11 of postnatal development. The role and response of the anterior lobe corticotrope was studied with immunocytochemical stains for ACTH on fixed embedded pituitaries from male rats 2-21 days of age. Serially section fields were stained for beta-chains of LH or FSH to test for joint storage of ACTH and one or both gonadotropins. Cell counts on semithin sections were used to determine the frequency of stained corticotropes in the developing pituitary. The 2-day-old rats had twice as many corticotropes (17.6%) as the adults (8.1%). During the stress-nonresponsive period, the frequency of corticotropes declined to 6.4% of the population. This was followed by a recovery to 16.9% at 15 days of age. The serial fields showed that stellate cells containing only ACTH declined sharply (by 95%) to less than 1% of the pituitary cell population during the first week of postnatal life. Cells containing ACTH and both gonadotropins predominated in the corticotrope population and were 4-6% of the pituitary cell populations during this time period. In the 15-day-old rats, the corticotropes included cells storing ACTH alone (5%) and the cells storing ACTH and both gonadotropins (9%). Throughout development, cells storing ACTH alone were distinguished by their intense staining, stellate shape, and peripheral granules. Cells storing ACTH and gonadotropins were stellate or ovoid and often resembled maturing gonadotropes. We hypothesize that this second group of cells serves a function related to adrenal-gonadal maturation, or they may be stem cells, abundant during development and present in relatively low percentages (1-3%) in adult rats.

An immunocytochemist's view of gonadotropin storage in the adult male rat: cytochemical and morphological heterogeneity in serially sectioned gonadotropes.

This study was designed to elucidate hormone storage patterns in gonadotropes with the use of ultrastructural immunocytochemistry on serial ultrathin sections. Sets of six serial sections were strained for beta chains of LH, FSH, or the C-Terminal sequence of ACTH, and 430 cells cut in triple or double serial section were collected from a group of seven normal adult male rats. Approximately 50--80% of the cells contained both LH and FSH, and most of these were Type I cells which are distinguished by their round shape and heterogeneous populations of secretion granules. Cells containing only FSH or LH constituted, on average, 19% of the population. These were a mixed group, morphologically, and included Type II cells distinguished by their angular shape and population of secretion granules, 250 nm in average diameter. Also among the FSH cells (and a few LH cells in two of the rats) were Type III cells, which resemble the corticotrope. On average, 10% of the serially sectioned cells contained only ACTH. Our findings show the presence of subpopulations of gonadotropes containing only one of the hormones, in numbers large enough to support the hypothesis that they may be partly responsible for the nonparallel release of gonadotropins. Also, the FSH-LH cells seemed to vary in their staining intensity for the two hormones, suggesting that the gondaotropes are a fluid, heterogeneous population of cells capable of storing both or only one of the hormones.

A critique of the contributions of immunoperoxidase cytochemistry to our understanding of pituitary cell function, as illustrated by our current studies of gonadotropes, corticotropes and endogenous pituitary GnRH and TRH.

The peroxidase-antiperoxidase technique has been used to study sites of pituitary hormone storage and binding. Some recent findings from our laboratory show that the technique can make intriguing contributions to our understanding of pituitary cell function. In serial, ultra-thin sections, one can identify two or three hormones in a given cell. During pre-pubertal development, gonadotropes may contain adrenocorticotropin immunoreactivity. Brain releasing hormones may be stored or sequestered in granules of cells they stimulate. This report includes a discussion and critique of our recent findings and interpretations which must be considered before one draws any conclusions about their biological significance.

An improved method for the collection of serial cells for electron microscopic analysis of their immunocytochemical stain.

A technique to find serial views of cells stained for more than one hormone is described. As the number of stains employed is increased, there is less probability that matching views for all stains will be found. We have found a set of 6 series (including 2 sections per grid and 3 alternating stains) to be optimal for recognition of morphology and collection of a significant number of cells.