Use of an endoscope-compatible probe to detect colonic dysplasia with Fourier transform infrared spectroscopy

Fourier transform infrared (FTIR) spectroscopy is sensitive to the molecular composition of tissue and has the potential to identify premalignant tissue (dysplasia) as an adjunct to endoscopy. We demonstrate collection of mid-infrared absorption spectra with a silver halide (AgCl(0.4)Br(0.6)) optical fiber and use spectral preprocessing to identify optimal subranges that classify colonic mucosa as normal, hyperplasia, or dysplasia. We collected spectra (n=83) in the 950 to 1800 cm(-1) regime on biopsy specimens obtained from human subjects (n=37). Subtle differences in the magnitude of the absorbance peaks at specific wave numbers were observed. The best double binary algorithm for distinguishing normal-versus-dysplasia and hyperplasia-versus-dysplasia was determined from an exhaustive search of spectral intervals and preprocessing techniques. Partial least squares discriminant analysis was used to classify the spectra using a leave-one-subject-out cross-validation strategy. The results were compared with histology reviewed independently by two gastrointestinal pathologists. The optimal thresholds identified resulted in an overall sensitivity, specificity, accuracy, and positive predictive value of 96%, 92%, 93%, and 82%, respectively. These results indicated that mid-infrared absorption spectra collected remotely with an optical fiber can be used to identify colonic dysplasia with high accuracy, suggesting that continued development of this technique for the early detection of cancer is promising.

Evaluation of multiple test methods for the detection of the novel 2009 influenza A (H1N1) during the New York City outbreak

BACKGROUND

In response to the novel influenza A H1N1 outbreak in the NY City area, 6090 patient samples were submitted over a 5-week period for a total of 14,114 viral diagnostic tests, including rapid antigen, direct immunofluorescence (DFA), viral culture and PCR. Little was known about the performance of the assays for the detection of novel H1N1 in the background of seasonal H1N1, H3N2 and other circulating respiratory viruses. In addition, subtyping influenza A became critical for the identification of high risk and/or hospitalized patients with novel H1N1 infection and for monitoring the spread of the outbreak.

STUDY DESIGN

This study analyzed the performances of the BinaxNOW Influenza A&B test (BinaxNOW), the 3M Rapid Detection Flu A+B test (3MA+B), direct immunofluorescence, R-Mix culture and the Luminex xTAG Respiratory Virus Panel (RVP) for the detection of seasonal influenza, novel H1N1 and other respiratory viruses. RVP was also evaluated for its ability to differentiate seasonal H1N1, H3N2 and novel H1N1.

RESULTS

The sensitivities, specificities, PPVs and NPVs for the detection of novel H1N1, determined by comparing all four-test methods, were: rapid antigen: 17.8%, 93.6%, 77.4%, 47.9%; DFA: 46.7%, 94.5%, 91.3%, 58.9%; R-Mix culture: 88.9%, 100%, 100%, 87.9%; RVP: 97.8%, 100%, 100%, 97.3%. The individual sensitivities of BinaxNOW and 3MA+B as compared to R-Mix culture for the detection of novel H1N1 were 9.6% and 40%, respectively. All unsubtypeable influenza A specimens identified by RVP and tested with the CDC novel H1N1 specific RT-PCR assay were confirmed to be novel H1N1.

CONCLUSIONS

Rapid antigen tests, DFA, R-Mix culture and the xTAG RVP test all detected the novel H1N1 strain, but with highly varied sensitivity. The RVP test provided the best diagnostic option as RVP demonstrated superior sensitivity for the detection of all influenza strains, including the novel H1N1, provided accurate influenza A subtyping and identified a significant number of additional respiratory pathogens.

Pancreatic adenocarcinoma patients with localised chronic severe pancreatitis show an increased number of single beta cells, without alterations in fractional insulin area

AIMS/HYPOTHESIS

Recent histological analysis of pancreases obtained from patients with long-standing type 1 diabetes identified chronic islet inflammation and limited evidence suggestive of beta cell replication. Studies in rodent models also suggest that beta cell replication can be induced by certain inflammatory cytokines and by gastrin. We therefore tested the hypothesis that beta cell replication is observed in non-autoimmune human pancreatic disorders in which localised inflammation or elevated gastrin levels are present.

METHODS

Resected operative pancreatic specimens were obtained from patients diagnosed with primary adenocarcinoma (with or without chronic severe pancreatitis) or gastrinoma. Additional pancreatic tissue was obtained from autopsy control patients. Immunohistochemistry was used to assess fractional insulin area, beta cell number and replication rate and differentiation factors relevant to beta cell development.

RESULTS

Fractional insulin area was similar among groups. Patients with pancreatic adenocarcinoma and localised chronic severe pancreatitis displayed significant increases in the number of single beta cells, as well as increased beta cell replication rate and levels of neurogenic differentiation 1 in islets. Patients with gastrinoma demonstrated significant increases in the number of single beta cells, but the beta cell replication rate and islet differentiation factor levels were similar to those in the control group.

CONCLUSIONS/INTERPRETATION

These findings indicate that chronic severe pancreatic inflammation can be associated with significant effects on beta cell number or replication rate, depending on the distribution of the cells. This information may prove useful for attempts seeking to design therapies aimed at inducing beta cell replication as a means of reversing diabetes.

Endoscopic evaluation of esophago-gastro-jejunostomy in rat model of Barrett's esophagus

Endoscopy can be used to monitor the onset of metaplastic transformation and to observe the progression of neoplasia in small animal models of Barrett's esophagus. By avoiding animal sacrifice, the natural history of this disease can be studied in a longitudinal fashion. We aim to characterize the endoscopic features of esophageal mucosa at various stages of the metaplasia-dysplasia-carcinoma sequence in a rat reflux model of Barrett's for comparison with histology. Acid and bile reflux was produced by introducing a side-to-side esophago-gastro-jejunostomy in Sprague-Dawley rats. Endoscopic examination of the distal esophagus was performed in 24 surgically altered and 4 control rats, between weeks 24 and 36 after the operation in 4-week intervals, and all rats were biopsied and sacrificed at 36 weeks. Endoscopic images were classified based on the surface mucosal patterns of the distal esophagus and then compared with histology. The endoscopic appearance was classified as: (i) normal, characterized by a smooth surface; (ii) intestinal metaplasia, defined as elevated plaques/ridges, deep grooves, and thin linear folds; (iii) dysplasia, indicated by coarse folds/grooves, meshlike villi, and foveolar appearance; and (iv) carcinoma, suggested by irregular-shaped mass lesions with ulcerations. The endoscopic criteria for intestinal metaplasia yielded a sensitivity of 100% in comparison with histology. Intestinal metaplasia with high-grade dysplasia was found in two rats and with low-grade dysplasia in three rats. Both focally invasive squamous cell carcinoma and invasive adenocarcinoma were found in one rat. Small animal endoscopy in a rat model of Barrett's esophagus can be used to perform surveillance, classify mucosal patterns, observe the onset of intestinal metaplasia, and monitor the progression of neoplastic transformation, representing a useful tool for studying the natural history of this disease.

The publishing game: reflections of an editorial team

The close of a 5-year editorship gives opportunity to reflect on the highs and the lows of an editorship. The goal of such reflection is to assist both authors and reviewers in interacting with a biomedical journal, and to foster interest among individuals contemplating an editorship. Among the highs was the privilege of publishing high-quality original scientific work within the scope of the journal; in this instance mechanistic studies of disease. Although review articles and editorials have their reward, it is the publication of original peer-reviewed work that constitutes the true basis for advancing biomedical science. This is the heart of journal publication. Second, the editorial interaction with submitting authors in bringing their work to publication is itself highly rewarding, and can lead to longer-term collegial working relationships between editors and authors. The anonymous expert reviewers also play a key role in bringing outstanding scientific work to successful publication. Collectively, authors, editors, and reviewers constitute an important 'community of science'. Third, working together as an editorial team, especially through the weekly 'journal clubs' that a regular editorial meeting affords, is commended as a key reward of any editorial group taking on journal management. The lows included sifting through submitted manuscripts in which the rigor of science was not satisfactory, and encountering specific instances of compromised scientific integrity--fortunately rare. In both instances, the editorial commitment is to publish high-quality original science; a necessary corollary is identifying those submissions, through rigorous but fair review, which do not meet journal standards. In the end, editorship is a highly rewarding experience, and very much conducive to sustaining the wonder of science that drew us to this profession.

Efficient rejection of scattered light enables deep optical sectioning in turbid media with low-numerical-aperture optics in a dual-axis confocal architecture

Miniature endoscopic microscopes, with subcellular imaging capabilities, will enable in vivo detection of molecularly-targeted fluorescent probes for early disease detection. To optimize a dual-axis confocal microscope (DACM) design for this purpose, we use a tabletop instrument to determine the ability of this technology to perform optical sectioning deep within tissue. First, we determine how tissue scattering deteriorates the diffraction-limited transverse and vertical responses in reflectance imaging. Specifically, the vertical response of a DACM to a plane reflector is measured at various depths in a scattering phantom and compared with diffraction theory and Monte Carlo scattering simulations. Similarly, transverse line scans across a knife-edge target are performed at various depths in a scattering phantom. Second, as a practical demonstration of deep-tissue fluorescence microscopy that corroborates the findings from our scattering experiments, 3-D fluorescence images are obtained in thick human gastrointestinal mucosal specimens. Our results demonstrate efficient rejection of scattered light in a DACM, which enables deep optical sectioning in tissue with subcellular resolution that can distinguish between normal and premalignant pathologies.

A clinical and histopathologic perspective on evolving noninvasive and invasive alternatives for liver biopsy

Noninvasive or minimally invasive alternatives are proposed as substitutes for liver biopsy and include clinical indices, cross-sectional imaging, serum biomarkers, liver stiffness measurement, and portal pressure measurement. Most alternatives to liver biopsy assess one aspect of liver disease and translate this into a numeric score. Overlap between categories may limit applications. Liver biopsy provides information about numerous variables: tissue architectural changes; necroinflammatory injury; fibrotic stage; alterations of parenchyma and bile duct epithelium; accumulation of fat, copper, and iron; and molecular and genetic changes. Liver biopsy may identify multiple disease etiologies. A single numeric score cannot be a substitute for complete histologic assessment. However, within defined clinical contexts, noninvasive assessment is an attractive alternative for many patients given the ease, avoidance of risk from invasive procedures, and validated contribution to clinical management. Serum biomarkers and liver stiffness assessment may become indispensable in longitudinal studies and to document outcome of treatments. The accuracy of the more reliable techniques is typically around 80%. Neither liver biopsy nor any single alternative option represents an absolute assessment of liver disease. Biopsy and alternatives are not mutually exclusive options. Liver biopsy and the noninvasive alternatives require a clear understanding of significance and limitations of each investigation. This places a responsibility on the clinician to consider fully the results of any of the investigative options used within the diagnostic and prognostic context of each individual patient, and to choose critically the most appropriate investigations for the patient's needs.

Detection of colonic dysplasia in vivo using a targeted heptapeptide and confocal microendoscopy

A combination of targeted probes and new imaging technologies provides a powerful set of tools with the potential to improve the early detection of cancer. To develop a probe for detecting colon cancer, we screened phage display peptide libraries against fresh human colonic adenomas for high-affinity ligands with preferential binding to premalignant tissue. We identified a specific heptapeptide sequence, VRPMPLQ, which we synthesized, conjugated with fluorescein and tested in patients undergoing colonoscopy. We imaged topically administered peptide using a fluorescence confocal microendoscope delivered through the instrument channel of a standard colonoscope. In vivo images were acquired at 12 frames per second with 50-microm working distance and 2.5-microm (transverse) and 20-microm (axial) resolution. The fluorescein-conjugated peptide bound more strongly to dysplastic colonocytes than to adjacent normal cells with 81% sensitivity and 82% specificity. This methodology represents a promising diagnostic imaging approach for the early detection of colorectal cancer and potentially of other epithelial malignancies.

The antigen for Hep Par 1 antibody is the urea cycle enzyme carbamoyl phosphate synthetase 1

Hepatocyte paraffin 1 (Hep Par 1), a murine monoclonal antibody, is widely used in surgical pathology practice to determine the hepatocellular origin of neoplasms. However, identity of the antigen for Hep Par 1 is unknown. The aim of this study was to characterize the Hep Par 1 antigen. To identify the antigen, immunoprecipitation was used to isolate the protein from human liver tissue, and a distinct protein band was detected at approximately 165 kDa. The protein band was also present in small intestinal tissue, but was not present in several other non-liver tissues nor in three human hepatocellular carcinoma cell lines, Huh-7, HepG2, and LH86. The protein was purified and analyzed by mass spectrometry. It was identified as carbamoyl phosphate synthetase 1 (CPS1). CPS1 is a rate-limiting enzyme in urea cycle and is located in mitochondria. We demonstrated that hepatoid tumors (gastric and yolk sac) were immunoreactive with both Hep Par 1 antibody and anti-CPS1 antibody, further confirming the results of mass spectrometric analysis. We found that the three human hepatocellular carcinoma cell lines do not express either CPS1 RNA or protein. We confirmed that the gene was present in these cell lines, suggesting that suppression of CPS1 expression occurs at the transcriptional level. This finding may have relevance to liver carcinogenesis, since poorly differentiated hepatocellular carcinomas exhibit poor to absent immunoreactivity to Hep Par 1. In conclusion, we have identified the antigen for Hep Par 1 antibody as a urea cycle enzyme CPS1. Our results should encourage further investigation of potential role that CPS1 expression plays in liver pathobiology and carcinogenesis.

The impact of review articles

The expansion of the scientific literature has produced a concomitant increase in the number of review articles. One may posit that the sheer number of review articles belies their function. This study examines the growth of the review literature, what types of journals publish these papers, and provides data on the citation rate of the review literature. Focus is given to the pathology literature, defined as papers that have the word 'pathology' or its derivatives in the title, abstract or as a key word. The pathology literature is proliferating at a rapid rate; from 1991 to 2006, the total number of original articles increased 2.3-fold, while the number of reviews increased 5.6-fold. Furthermore, in that same time frame, approximately 90% of pathology articles and reviews were not published in pathology journals. An examination of the 538 review articles that were published in pathology journals in 2005 reveals that only 21% of them have been cited more than 10 times since their publication. The impact factors of 12 pathology journals were compared with and without review articles for the period 2000-2006, including The American Journal of Pathology (AJP), The Journal of Pathology (JP) and Laboratory Investigation (LI). Inclusion of reviews increased the impact factor for JP by 0.610+/-0.153 U (+/-s.d.), which was significantly greater than that for AJP (0.109+/-0.086) and LI (0.147+/-0.088). However, for all three journals the total impact factor was largely a reflection of the citations of original articles. The motivations of authors and editors who produce review articles are considered, such as career progress and increasing journal visibility, respectively. The fact that many review articles are poorly cited raises concern about the harm that poor review articles can cause, first by making it more difficult to find the good reviews, and in the worst case by propagating scientific error through lack of critical appraisal of original research. The attributes of the best reviews that serve to shape the future of science are described. These data are presented with the hope that authors and editors will carefully consider their respective roles in ensuring that the body of review literature will be of maximum benefit to the scientific and biomedical community.

Hepatitis C virus triggers apoptosis of a newly developed hepatoma cell line through antiviral defense system

BACKGROUND & AIMS

Hepatitis C virus (HCV) has a tendency to cause chronic viral infection. Viral evasion of host immune systems plays a key role in the pathogenesis of HCV. However, the interaction between HCV and hepatocyte innate antiviral defense systems is not understood. The aim of this study was to examine how human hepatocytes respond to HCV infection.

METHODS

We have established a novel human hepatoma cell line, LH86, from a well-differentiated hepatocellular carcinoma tissue. An infectious HCV isolate, JFH-1, was used to infect LH86 cells. HCV replication and apoptosis after viral infection were examined. Mechanisms of HCV-induced apoptosis were determined. Type I interferon induction and the relevant signaling molecules were examined.

RESULTS

LH86 cells permitted JFH-1 HCV infection. The viral infection caused massive apoptosis. The apoptosis was related to viral replication, because blocking viral entry with anti-CD81 or suppressing viral replication with interferon protected cells from HCV-induced apoptosis. The HCV-induced apoptosis appeared to be triggered by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptors, death receptor 4 and death receptor 5, which were up-regulated in HCV infection. HCV also activated interferon response factor 3, which induced expression of interferon and TRAIL in LH86 cells.

CONCLUSIONS

Our study showed that a specific HCV isolate, JFH-1, is cytopathic in this new hepatoma cell line. LH86 cells mount an intact innate antiviral defense through induction of interferon and triggering apoptosis of infected cells. This study reveals a novel mechanism by which host hepatocytes respond to acute HCV infection.

Functional imaging of colonic mucosa with a fibered confocal microscope for real-time in vivo pathology

BACKGROUND & AIMS

Histologic interpretation of disease currently is performed with static images of excised tissues, and is limited by processing artifact, sampling error, and interpretive variability. The aim of this study was to show the use of functional optical imaging of viable mucosa for quantitative evaluation of colonic neoplasia in real time.

METHODS

Fluorescein (5 mg/mL) was administered topically in 54 human subjects undergoing screening colonoscopy. Fluorescence images were collected with 488-nm excitation at 12 frames/s with the confocal microendoscopy system. Movement of fluorescein in the transient period (<5 s) and the lamina propria:crypt contrast ratio in the steady-state phase (>5 s) were quantified.

RESULTS

Normal mucosa showed circular crypts with uniform size, hyperplasia revealed proliferative glands with serrated lumens, and adenomas displayed distorted elongated glands. For t less than 5 seconds, fluorescein passed through normal epithelium with a peak speed of 1.14 +/- 0.09 microm/s at t = 0.5 seconds, and accumulated into lamina propria as points of fluorescence that moved through the interglandular space with an average speed of 41.7 +/- 3.4 microm/s. Passage of fluorescein through adenomatous mucosa was delayed substantially. For t greater than 5 seconds, high sensitivity, specificity, and accuracy was achieved using a discriminant function to evaluate the contrast ratio to distinguish normal from lesional mucosa (91%, 87%, and 89%, respectively; P < .001), hyperplasia from adenoma (97%, 96%, and 96%, respectively; P < .001), and tubular from villous adenoma (100%, 92%, and 93%, respectively; P < .001).

CONCLUSIONS

Confocal imaging can be performed in vivo to assess the functional behavior of tissue in real time for providing pathologic interpretation, representing a new method for histologic evaluation.

Detection of endogenous biomolecules in Barrett's esophagus by Fourier transform infrared spectroscopy

Fourier transform infrared (FTIR) spectroscopy provides a unique molecular fingerprint of tissue from endogenous sources of light absorption; however, specific molecular components of the overall FTIR signature of precancer have not been characterized. In attenuated total reflectance mode, infrared light penetrates only a few microns of the tissue surface, and the influence of water on the spectra can be minimized, allowing for the analyses of the molecular composition of tissues. Here, spectra were collected from 98 excised specimens of the distal esophagus, including 38 squamous, 38 intestinal metaplasia (Barrett's), and 22 gastric, obtained endoscopically from 32 patients. We show that DNA, protein, glycogen, and glycoprotein comprise the principal sources of infrared absorption in the 950- to 1,800-cm(-1) regime. The concentrations of these biomolecules can be quantified by using a partial least-squares fit and used to classify disease states with high sensitivity, specificity, and accuracy. Moreover, use of FTIR to detect premalignant (dysplastic) mucosa results in a sensitivity, specificity, positive predictive value, and total accuracy of 92%, 80%, 92%, and 89%, respectively, and leads to a better interobserver agreement between two gastrointestinal pathologists for dysplasia (kappa = 0.72) versus histology alone (kappa = 0.52). Here, we demonstrate that the concentration of specific biomolecules can be determined from the FTIR spectra collected in attenuated total reflectance mode and can be used for predicting the underlying histopathology, which will contribute to the early detection and rapid staging of many diseases.

Validation of novel optical imaging technologies: the pathologists' view

Noninvasive optical imaging technology has the potential to improve the accuracy of disease detection and predict treatment response. Pathology provides the critical link between the biological basis of an image or spectral signature and clinical outcomes obtained through optical imaging. The validation of optical images and spectra requires both morphologic diagnosis from histopathology and parametric analysis of tissue features above and beyond the declared pathologic "diagnosis." Enhancement of optical imaging modalities with exogenously applied biomarkers also requires validation of the biological basis for molecular contrast. For an optical diagnostic or prognostic technology to be useful, it must be clinically important, independently informative, and of demonstrated beneficial value to patient care. Its usage must be standardized with regard to methods, interpretation, reproducibility, and reporting, in which the pathologist plays a key role. By providing insight into disease pathobiology, interpretive or quantitative analysis of tissue material, and expertise in molecular diagnosis, the pathologist should be an integral part of any team that is validating novel optical imaging modalities. This review will consider (1) the selection of validation biomarkers; (2) standardization in tissue processing, diagnosis, reporting, and quantitative analysis; (3) the role of the pathologist in study design; and (4) reference standards, controls, and interobserver variability.

Hepatocellular carcinoma arising from ectopic liver tissue in the pancreas

Liver tissue ectopia is a well-documented phenomenon. Rarely, hepatocellular carcinoma arises from the ectopic liver tissue. In this paper, we report a case of a primary, well-differentiated hepatocellular carcinoma arising from ectopic liver tissue in the pancreas. The patient is a 58-year-old Hispanic man with no history of underlying liver diseases or chronic pancreatic diseases. Patient presented with a several days history of abdominal pain with radiation to his right upper quadrant. Imaging study revealed a 3.7 x 3.3-cm mass in the distal pancreas. No other lesions were identified. Preoperative fine needle aspiration revealed blood and atypical hepatocytes. The patient underwent distal pancreatectomy and splenectomy for suspected neuroendocrine tumor. Gross examination revealed a well-circumscribed 3.3-cm, beige-tan, pseudolobulated tumor with focal areas of hyperpigmentation. A microscopic examination revealed hepatoid cells arranged in a trabecular pattern with focal bile pigment. Immunohistochemistry study showed that the tumor cells were reactive with hepatocyte antigen (Hep par 1), alpha-1 antitrypsin, but negative for synaptophysin and chromogranin. Immunostain for polyclonal carcinoembryonic antigen showed a typical bile canalicular pattern. These results support that this tumor in the pancreas is hepatocellular carcinoma, most likely arising from ectopic liver tissue within the pancreas.

Adequacy of pathology resident training for employment: a survey report from the Future of Pathology Task Group

CONTEXT

The recent change in accreditation requirements for anatomic pathology and clinical pathology residency training from 5 to 4 years and the rapid advances in technologies for pathology services have sparked a renewed debate over the adequacy of pathology residency training. In particular, perceived deficiencies in training have been declared from a variety of sources, both in the form of recent editorial opinions and from surveys of community hospital pathologist employers in 1998, 2003, and 2005 by Dr Richard Horowitz.

OBJECTIVE

To obtain more comprehensive data on the perceptions of strengths and weaknesses in pathology residency training.

DESIGN

The College of American Pathologists conducted a survey of potential pathology employers (senior College of American Pathologists members, members designated as head of group, and members of the Association of Directors of Anatomic and Surgical Pathology). Also surveyed were recent graduates of pathology residency programs, who were identified as being junior members of the College of American Pathologists, were recent recipients of certification from the American Board of Pathology, or were contacted through their directors of pathology residency programs.

RESULTS

There were 559 employer respondents, of whom 384 were responsible for hiring and/or supervising new pathologists. There were 247 recent graduates of pathology residency training programs who responded. From the employers' standpoint, the majority expressed overall satisfaction with recent graduates, but almost one third of employers indicated that new hires had a major deficiency in a critical area. Specific areas of deficiency were clinical laboratory management and judgment in ordering special stains and studies. In addition, one half of employers agreed that more guidance and support for newly trained pathologists is needed now than was required 10 years ago. Academic employers generally were more satisfied than private sector employers. Newly trained pathologists did not appear to be inappropriately overconfident in their abilities. In addition, their perceptions of those specific areas in which they are most and least prepared are very similar to the ratings provided by employers. On average, newly trained pathologists' ratings of their own preparedness are highest for specific aspects of general pathology and anatomic pathology, and lowest for specific aspects of clinical pathology and administration. In selecting new pathologists, employers perceived medical knowledge and interpersonal skills as the most important discriminating applicant characteristics. When new employees were asked why they thought they were offered their position, the discriminating qualifications cited most often were academic background and training, as well as completion of a fellowship and subspecialty training.

CONCLUSIONS

It is our hope that the results of this survey can be used as input for further discussions and recommendations for training of pathology residents so as to further advance the ability of pathologists to provide quality patient care upon their graduation from training.

Original research in pathology: judgment, or evidence-based medicine?

Pathology is both a medical specialty and an investigative scientific discipline, concerned with understanding the essential nature of human disease. Ultimately, pathology is accountable as well, as measured by the accuracy of our diagnoses and the resultant patient care outcomes. As such, we must consider the evidence base underlying our practices. Within the realm of Laboratory Medicine, extensive attention has been given to testing accuracy and precision. Critical examination of the evidence base supporting the clinical use of specific laboratory tests or technologies is a separate endeavor, to which specific attention must be given. In the case of anatomic pathology and more specifically surgical pathology, the expertise required to render a diagnosis is derived foremost from experience, both personal and literature-based. In the first instance, knowledge of the linkage between one's own diagnoses and individual patient outcomes is required, to validate the role of one's own interpretations in the clinical course of patients. Experience comes from seeing this linkage first hand, from which hopefully comes wisdom and, ultimately, good clinical judgment. In the second instance, reading the literature and learning from experts is required. Only a minority of the relevant literature is published in pathology journals to which one may subscribe. A substantial portion of major papers relevant to the practice of anatomic pathology are published in collateral clinical specialty journals devoted to specific disease areas or organs. Active effort is therefore required to seek out the literature beyond the domain of pathology journals. In examining the published literature, the essential question then becomes: Does the practice of anatomic pathology fulfill the tenets of 'evidence-based medicine' (EBM)? If the pinnacle of EBM is 'systematic review of randomized clinical trials, with or without meta-analysis', then anatomic pathology falls far short. Our published literature is largely observational in nature, with reports of case series (with or without statistical analysis) constituting the majority of our 'evidence base'. Moreover, anatomic pathology is subject to 'interobserver variation', and potentially to 'error'. Taken further, individual interpretation of tissue samples is not an objective endeavor, and it is not easy to fulfill the role of a 'gold standard'. Both for rendering of an overall interpretation, and for providing the semi-quantitative and quantitative numerical 'scores' which support evidence-based clinical treatment algorithms, the Pathologist has to exercise a high level of interpretive judgment. Nevertheless, the contribution of anatomic pathology to 'EBM' is remarkably strong. To the extent that our judgmental interpretations become data, our tissue interpretations become the arbiters of patient care management decisions. In a more global sense, we support highly successful cancer screening programs, and play critical roles in the multidisciplinary management of complex patients. The true error is for the clinical practitioners of 'EBM' to forget the contribution to the supporting evidence base of the physicians that are Anatomic Pathologists. Finally, the academic productivity of pathology faculty who operate in the clinical realm must be considered. A survey of six North American academic pathology departments reveals that 26% of all papers published in 2005 came from 'unfunded' clinical faculty. While it is likely that their academic productivity is lower than that of 'funded' research faculty, the contribution of clinical faculty to the knowledge base for the practice of modern medicine, and to the academic reputation of the department, must not be overlooked. The ability of clinical faculty in academic departments of pathology to pursue original scholarship must be supported if our specialty is to retain its preeminence as an investigative scientific discipline in the age of EBM.

Early histologic changes in fibrosing cholestatic hepatitis C

Recurrent hepatitis C (RHCV) after liver transplantation is almost universal, and occasional patients will have an aggressive course characterized histologically by pericellular/sinusoidal fibrosis and cholestasis, known as fibrosing cholestatic hepatitis (FCH). The early stages and evolution of this disease have not been well characterized. A total of 77 liver biopsies performed for indication (nonprotocol) were evaluated for necroinflammation, rejection, cholestasis, and fibrosis. Control groups were composed of protocol biopsies from HCV transplant patients (10 biopsies) as well as non-HCV transplant patients (6 biopsies). Scoring for necroinflammation, rejection, and fibrosis were compiled using standard criteria (hepatic activity index, Banff, Ishak, METAVIR). Pericellular fibrosis was staged with a novel "sinusoidal" system. A cholestasis scoring system was developed to quantitate parenchymal and portal features of cholestasis. Biopsies were categorized as rejection, RHCV, FCH, and stable based on histology and clinical information. FCH was found to have a higher fibrosis stage overall when compared to most diagnostic groups, regardless of the staging system used. Additionally, sinusoidal fibrosis was significantly higher in the FCH diagnosis group. Cholestasis was more prominent in biopsies of FCH in all comparisons. In conclusion, the presence of cholestasis and fibrosis with mild to moderate RHCV should raise the suspicion of FCH. When studying the evolution of these cases, the first abnormality to appear is RHCV and cholestasis, fibrosis develops soon after, and both continue to worsen until the point of allograft failure or patient death.

Dual-axes confocal reflectance microscope for distinguishing colonic neoplasia

A dual-axes confocal reflectance microscope has been developed that utilizes a narrowband laser at 1310 nm to achieve high axial resolution, image contrast, field of view, and tissue penetration for distinguishing among normal, hyperplastic, and dysplastic colonic mucosa ex vivo. Light is collected off-axis using a low numerical aperture objective to obtain vertical image sections, with 4- to 5-microm resolution, at tissue depths up to 610 microm. Post-objective scanning enables a large field of view (610 x 640 microm), and balanced-heterodyne detection provides sensitivity to collect vertical sections at one frame per second. System optics are optimized to effectively reject out-of-focus scattered light without use of a low-coherence gate. This design is scalable to millimeter dimensions, and the results demonstrate the potential for a miniature instrument to detect precancerous tissues, and hence to perform in vivo histopathology.

Hepatitic inherited metabolic disorders

Primary metabolic disorders are a disparate group of diseases that may or may not be accompanied by hepatic manifestations. Those with liver involvement may show a range of histopathologic changes. Proper histologic diagnosis requires correlation with clinical and laboratory data, including evaluation for mutations either via serum protein electrophoresis or through formal genetic analysis. This article is a review of the three most common inherited metabolic disorders which may present with a hepatitic pattern. In alpha1-antitrypsin disorder, there is a broad range of clinical presentations, age at presentation, and histological features ranging from "neonatal hepatitis" to a chronic progressive hepatitis in later childhood and adulthood. Hence, this disorder must be in the differential diagnosis of liver disease of the very young, and in older children and adults, with or without coexistent overt pulmonary symptoms. In Wilson disease, presentation tends to be in older childhood or the adult, with a progressive chronic hepatitis. Cystic fibrosis may feature a characteristic obstructive biliary syndrome, coexisting with the many extrahepatic manifestations of this debilitating disease. Lastly, the progressive familial intrahepatic cholestasis (PFIC) syndromes are given as examples of inherited metabolic conditions in which relentlessly progressive cholestatic liver disease eventuates over years in end-stage cholestatic liver disease with cirrhosis. Distinguishing features include absence of elevated serum gamma-glutamyl transpeptidase (GGT) in PFIC-1 and PFIC-2, and elevated GGT in PFIC-3. However, molecular studies are required for a confident diagnosis of the rare PFIC syndromes.

Evidence-based interpretation of liver biopsies

'Evidence based medicine' is a paradigm introduced in the 1990s in which collection of clinical data in a reproducible and unbiased way is intended to guide clinical decision-making. This paradigm has been promulgated across the spectrum of medicine, but with more limited critical analysis in the realm of pathology. The 'evidence base' in support of our practices in Anatomic Pathology is a critical issue, given the key role that such diagnoses play in patient management decisions. The question is, 'On what basis are diagnostic opinions rendered in Anatomic Pathology?' The operative question becomes, 'What is the published literature that supports our anatomic pathology interpretations?' This second question was applied to the published literature in Hepatopathology, by identifying the 'citation classics' of this discipline. Specifically, the top 150 most-cited liver pathology articles were analyzed for: authorship; journal of publication; type of publication; and year of publication. Results are as follows. First, it is indeed true that the preeminent hepatopathologists of the age are the most cited authors in the 'top 150'. Second, the most cited articles in hepatopathology are not published in the pathology literature, but are instead published in much higher impact clinical journals. Third, the pathology of viral hepatitis is demonstrated to be extraordinarily well-grounded in 'evidence based medicine'. Much of the remainder of the hepatopathology literature falls into a 'narrative based' paradigm, which is the rigorous reporting of case experience without statistical clinical outcomes validation. Finally, the years of publication reflect, on the one hand, a vigorous recent literature in the pharmaceutical treatment of viral hepatitis, and on the other, a broadly distributed set of 'narrative' articles from the 1960s, 1970s, 1980s, and 1990s. In conclusion, the discipline of hepatopathology appears to be well-grounded in 'evidence based medicine' in the realm of viral hepatitis. The remainder of our discipline rests predominantly upon the time-honored identification of disease process through the publication of narrative case series.