David J. Zahniser

Utility of liquid-based cytology for cervical carcinoma screening: Results of a population-based study conducted in a region of Costa Rica with a high incidence of cervical carcinoma

In a study using a split‐sample design, liquid‐based cytology (ThinPrep® Processor, Cytyc Corporation, Boxborough, MA) was compared with the conventional Papanicolaou (Pap) smear in Guanacaste, Costa Rica. The study provides the first population‐based comparison of the ThinPrep® screening technology and includes “gold standard” measures of diagnostic accuracy.

Cervical specimens collected in liquid buffer are suitable for both cytologic screening and ancillary human papillomavirus testing

Several new techniques have been developed to improve the sensitivity of cervical carcinoma screening and reduce equivocal cytologic diagnoses referred to as atypical squamous cells of undetermined significance (ASCUS). This study evaluates the effectiveness of combining two newly introduced diagnostic techniques: preparation of thin‐layer cytologic slides from ThinPrep liquid buffer and selected Hybrid Capture testing for human papillomavirus (HPV) DNA. Because HPV DNA detection has been strongly associated with the presence of a cervical carcinoma precursor (“squamous intraepithelial lesion,” or SIL), HPV testing might be useful for identifying women with ASCUS who have an underlying SIL.

Differentiation in Male Ferrets of a Sexually Dimorphic Nucleus of the Preoptic/Anterior Hypothalamic Area Requires Prenatal Estrogen

Experiments were conducted to determine when during perinatal development testicular steroids act in ferrets to promote the organization of a bilateral nucleus in a medial position at the border of the preoptic area (POA) and anterior hypothalamus (AH), henceforth referred to as the male nucleus of the POA/AH (MN-POA/AH). The formation of the MN-POA/AH was promoted in female offspring by treating their mothers with testosterone over the last 11 days of the 42-day gestation period, whereas MN-POA/AH formation was not disrupted in males castrated within 1, 2 or 5 days of birth. Additional experiments were conducted to determine whether the active hormone which induces differentiation of the MN-POA/AH in the male ferret is an androgen or an estrogen. MN-POA/AH formation was inhibited in males deprived prenatally of estrogenic stimulation via maternal ovariectomy and subcutaneous implantation of the aromatase inhibitor 1,4,6-androstatriene-3,17-dione (ATD) on gestational day 30. By contrast, MN-POA/AH formation was not disrupted in males exposed prenatally to the antiandrogen flutamide. These results imply that estrogen, derived from the neural aromatization of circulating testosterone, acts prenatally to promote the organization of the MN-POA/AH in male ferrets. The development of sex-dependent features of forebrain morphology may depend on the neural action of estrogen in males of diverse mammalian species.

Changes in populations of LHRH-immunopositive cell bodies following gonadectomy ☆

One day after castration of male rats, plasma LH rose and the number of LHRH immunopositive neuronal perikarya decreased. As plasma LH continued to rise six days and three weeks post-castration, the number of LHRH immunopositive neurons also increased. The largest population of LHRH immunopositive neurons was detected three weeks post-castration and the cell group that showed the greatest increase was in the rostral preoptic area. In females, the largest population of LHRH immunopositive neurons was observed one day post-ovariectomy; at this time plasma LH levels were not significantly elevated above diestrous levels. Six days post-ovariectomy, LH levels were elevated and the number of LHRH immunopositive cells decreased. As LH levels continued to rise three weeks post-ovariectomy, the population increased in size. In males, primarily LHRH cells of the rostral preoptic area increased in in number; in females, the cell groups that increased were scattered over the diagonal band of Broca, preoptic and anterior hypothalamic areas. Although LHRH neurons demonstrated these variations following gonadectomy, there was no evidence of alteration(s) in molecular processing of precursor hormone.

Automated system for the analysis of muscle and nerve biopsies.

An automated system has been developed for morphometric analysis of muscle and nerve fibers as seen in routine biopsy tissue preparations. This system, which is suitable both for research and clinical applications, is now in routine use at New England Medical Center Hospital. It is designed around commonly available hardware and uses our own custom software. Special sample preparation is not required, and the system will process almost any biopsy that is free from obvious artifact and suitable for manual assessment. In a typical biopsy, the system provides nearly full automation for the edge (boundary) determination of over 90%of the fibers encountered. An efficient, interactive mode allows for rapid analysis of the remaining 10%. Once fiber boundaries are determined, the system provides fully automatic measurement of the usual parameters such as fiber diameter, as well as a number of parameters not routinely measured with existing manual techniques. Typical analysis times are 35 min for muscle and 2 h for nerve. Complete report generation is provided, with hardcopy available in the pathologists office. This paper describes the operational aspects of the use of the automated analysis system in routine biopsy work.

Automated slide preparation system for the clinical laboratory

An automated device has been developed to prepare a wide variety of cytology preparations. Using the device, cells collected in suspension are mildly dispersed and transferred to a glass slide using filter-transfer technology. The cell density on the slide is controlled by the instrument. A companion product, the solution used in specimen transport and preparation, provides long-term preservation of diagnostic cells while lysing red blood cells. The overall process yields clean, uniform samples with better visualization of the diagnostic cells. The use of a disposable filter prevents sample-to-sample contamination. Collection of the sample in solution makes it possible to produce multiple slides from one sample.

Automation of Pap Smear Analysis: A Review and Status Report

In most western countries approximately one fourth of all deaths are attributable to some form of cancer. It is generally believed that when a developing cancer is detected at a stage at which its extent is still limited there is a good chance that it can be eradicated, allowing the patient to continue to lead a normal life. Cancer of the uterine cervix is one type of cancer with which “early detection” and treatment of cytologically detectable precancerous abnormalities seem to lead to a significant decline in the incidence of and deaths from later stages of cancer.

Computerized contextual analysis in diagnosis

Cervical cytology specimens prepared as monolayers were analyzed with a combination of high-resolution single-cell image analysis and lower-resolution contextual image analysis. For the latter, quantitative features of cluster architecture, object distribution and background were used to mimic the pathologists global assessment of a specimen. Contextual analysis correctly classified 81% of the cases for diagnosis, about on a par with the companion single-cell cytometric analysis. Contextual and single cell analysis complemented each other, yielding greater accuracy when the two methods were combined. Additional applications of contextual analysis are discussed.

Diagnosis of invasive cervical carcinoma with fluid-based, thin-layer slide preparation method

Objectives: Although the main role of the Papanicolaou smear is to detect precursors of cervical cancer, the detection of invasive disease is important to identify women at the earliest stage of their disease. This study assesses the ability of the ThinPrep Papanicolaou test to identify invasive cervical cancer as compared to the Papanicolaou smear.Methods: A meta-analysis of five studies previously reviewed by the Food and Drug Administration was performed. There were 61 cases of cervical carcinoma processed by both conventional Papanicolaou smear and ThinPrep methods. Each case was reviewed by cytotechnologists and cytopathologists without knowledge of prior diagnoses. In a sub-study, the filtrate resulting from the preparation of the ThinPrep was analyzed to determine if diagnostic cells passed through the filter membrane.Results: With the ThinPrep method, a diagnosis of cancer was made in 54 cases (88.5%) as compared to a diagnosis of cancer in 52 of these cases with the conventional Papanicolaou smear method (85.2%). In those cases where diagnosis of invasive cancer was not made with the ThinPrep method, all cases were classified as abnormal, ranging from atypical glandular cells of undetermined significance to high-grade squamous intraepithelial lesions. The ThinPrep slides contained tumor diathesis and other contextual clues. Analysis of the ThinPrep filtrate demonstrated that cancer cells did not pass through the filter.Conclusions: These studies indicate that the ThinPrep method is at least equivalent to the conventional Papanicolaou smear method for the demonstration of squamous cell carcinoma, adenocarcinoma, and other cervical malignancies. Diagnostically important cells are not lost through the filter membrane during the preparation of the ThinPrep slide, because they are larger than the 8 µm pore size of the filter.