Fast, Accurate, and Versatile Data Analysis Platform for the Quantification of Molecular Spatiotemporal Signals

Optical recording of intricate molecular dynamics is becoming an indispensable technique for biological studies, accelerated by the development of new or improved biosensors and microscopy technology. This creates major computational challenges to extract and quantify biologically meaningful patterns embedded within complex and rich data sources. Here, we introduce Activity Quantification and Analysis (AQuA2), a fast, accurate and versatile data analysis platform built upon advanced machine learning techniques. It decomposes complex live imaging-based datasets into elementary signaling events, allowing accurate and unbiased quantification of molecular activities and identification of consensus functional units. We demonstrate applications across a range of biosensors (calcium, norepinephrine, ATP, acetylcholine, dopamine), cell types (astrocytes, oligodendrocytes, microglia, neurons), organs (brains and spinal cords), animal models (zebrafish and mouse), and imaging modalities (confocal, two-photon, light sheet). As exemplar findings, we show how AQuA2 identified drug-dependent interactions between neurons and astroglia, and distinct sensorimotor signal propagation patterns in the mouse spinal cord.

A New Transgenic Tool to Study the Ret Signaling Pathway in the Enteric Nervous System

The receptor tyrosine kinase Ret plays a critical role in regulating enteric nervous system (ENS) development. Ret is important for proliferation, migration, and survival of enteric progenitor cells (EPCs). Ret also promotes neuronal fate, but its role during neuronal differentiation and in the adult ENS is less well understood. Inactivating RET mutations are associated with ENS diseases, e.g., Hirschsprung Disease, in which distal bowel lacks ENS cells. Zebrafish is an established model system for studying ENS development and modeling human ENS diseases. One advantage of the zebrafish model system is that their embryos are transparent, allowing visualization of developmental phenotypes in live animals. However, we lack tools to monitor Ret expression in live zebrafish. Here, we developed a new BAC transgenic line that expresses GFP under the ret promoter. We find that EPCs and the majority of ENS neurons express ret:GFP during ENS development. In the adult ENS, GFP⁺ neurons are equally present in females and males. In homozygous mutants of ret and sox10-another important ENS developmental regulator gene-GFP⁺ ENS cells are absent. In summary, we characterize a ret:GFP transgenic line as a new tool to visualize and study the Ret signaling pathway from early development through adulthood.

Dopamine activates astrocytes in prefrontal cortex via α1-adrenergic receptors

The prefrontal cortex (PFC) is a hub for cognitive control, and dopamine profoundly influences its functions. In other brain regions, astrocytes sense diverse neurotransmitters and neuromodulators and, in turn, orchestrate regulation of neuroactive substances. However, basic physiology of PFC astrocytes, including which neuromodulatory signals they respond to and how they contribute to PFC function, is unclear. Here, we characterize divergent signaling signatures in mouse astrocytes of the PFC and primary sensory cortex, which show differential responsiveness to locomotion. We find that PFC astrocytes express receptors for dopamine but are unresponsive through the Gs/Gi-cAMP pathway. Instead, fast calcium signals in PFC astrocytes are time locked to dopamine release and are mediated by α1-adrenergic receptors both ex vivo and in vivo. Further, we describe dopamine-triggered regulation of extracellular ATP at PFC astrocyte territories. Thus, we identify astrocytes as active players in dopaminergic signaling in the PFC, contributing to PFC function though neuromodulator receptor crosstalk.

Pittolo et al. demonstrate that the neuromodulator dopamine targets astrocytes, a type of brain cell, via receptors specific to another neuromodulator—norepinephrine. This study provides groundwork on how dopamine affects non-neuronal brain cells and suggests that crosstalk between neuromodulatory pathways occurs in vivo, with possible clinical implications.

Magnetomicrometry

We live in an era of wearable sensing, where our movement through the world can be continuously monitored by devices. Yet, we lack a portable sensor that can continuously monitor muscle, tendon, and bone motion, allowing us to monitor performance, deliver targeted rehabilitation, and provide intuitive, reflexive control over prostheses and exoskeletons. Here, we introduce a sensing modality, magnetomicrometry, that uses the relative positions of implanted magnetic beads to enable wireless tracking of tissue length changes. We demonstrate real-time muscle length tracking in an in vivo turkey model via chronically implanted magnetic beads while investigating accuracy, biocompatibility, and long-term implant stability. We anticipate that this tool will lay the groundwork for volitional control over wearable robots via real-time tracking of muscle lengths and speeds. Further, to inform future biomimetic control strategies, magnetomicrometry may also be used in the in vivo tracking of biological tissues to elucidate biomechanical principles of animal and human movement.

On prosthetic control: A regenerative agonist-antagonist myoneural interface

Prosthetic limb control is fundamentally constrained by the current amputation procedure. Since the U.S. Civil War, the external prosthesis has benefited from a pronounced level of innovation, but amputation technique has not significantly changed. During a standard amputation, nerves are transected without the reintroduction of proper neural targets, causing painful neuromas and rendering efferent recordings infeasible. Furthermore, the physiological agonist-antagonist muscle relationships are severed, precluding the generation of musculotendinous proprioception, an afferent feedback modality critical for joint stability, trajectory planning, and fine motor control. We establish an agonist-antagonist myoneural interface (AMI), a unique surgical paradigm for amputation. Regenerated free muscle grafts innervated with transected nerves are linked in agonist-antagonist relationships, emulating the dynamic interactions found within an intact limb. Using biomechanical, electrophysiological, and histological evaluations, we demonstrate a viable architecture for bidirectional signaling with transected motor nerves. Upon neural activation, the agonist muscle contracts, generating electromyographic signal. This contraction in the agonist creates a stretch in the mechanically linked antagonist muscle, producing afferent feedback, which is transmitted through its motor nerve. Histological results demonstrate regeneration and the presence of the spindle fibers responsible for afferent signal generation. These results suggest that the AMI will not only produce robust signals for the efferent control of an external prosthesis but also provide an amputee's central nervous system with critical musculotendinous proprioception, offering the potential for an enhanced prosthetic controllability and sensation.

Relocation of an Extrasynaptic GABAA Receptor to Inhibitory Synapses Freezes Excitatory Synaptic Strength and Preserves Memory

The excitatory synapse between hippocampal CA3 and CA1 pyramidal neurons exhibits long-term potentiation (LTP), a positive feedback process implicated in learning and memory in which postsynaptic depolarization strengthens synapses, promoting further depolarization. Without mechanisms for interrupting positive feedback, excitatory synapses could strengthen inexorably, corrupting memory storage. Here, we reveal a hidden form of inhibitory synaptic plasticity that prevents accumulation of excitatory LTP. We developed a knockin mouse that allows optical control of endogenous α5-subunit-containing γ-aminobutyric acid (GABA)A receptors (α5-GABARs). Induction of excitatory LTP relocates α5-GABARs, which are ordinarily extrasynaptic, to inhibitory synapses, quashing further NMDA receptor activation necessary for inducing more excitatory LTP. Blockade of α5-GABARs accelerates reversal learning, a behavioral test for cognitive flexibility dependent on repeated LTP. Hence, inhibitory synaptic plasticity occurs in parallel with excitatory synaptic plasticity, with the ensuing interruption of the positive feedback cycle of LTP serving as a possible critical early step in preserving memory.

Tonic-clonic seizure after unrecognized unintentional dural puncture

Patients who suffer an unintentional dural puncture have a high risk of developing a post-dural puncture headache. Other neurologic complications have been reported, but seizure is rarely seen. We present a case of a 21-year-old primigravida who experienced an unrecognized unintentional dural puncture that ultimately resulted in a tonic-clonic seizure from intracranial hypotension one week following the dural breach. Her trachea was intubated and she was transferred to the intensive care unit. Two epidural blood patches, performed by neuroradiologists, were needed before the patient experienced complete resolution of her headache. During the re-admission, she also experienced a pulmonary embolus which further lengthened her hospital stay.

Composite removal by means of erbium, chromium:yttrium-scandium-gallium-garnet laser compared with rotary instruments

BACKGROUND

Complete removal of existing composite restorations without unnecessary removal of tooth structure is challenging. The authors compared the amount of tooth structure removed and composite remaining in Class III preparations when using an erbium laser or a rotary instrument.

METHODS

Mesiolingual and distolingual preparations were prepared in 14 extracted anterior teeth, restored with shade-matched composite, finished, and polished. One restoration was removed with an erbium, chromium:yttrium-scandium-gallium-garnet laser and the other with a rotary instrument (handpiece and carbide burs). Gypsum models made from vinyl polysiloxane impressions of the preparation and removal stages were scanned. The 2 scans were precisely aligned to calculate the amount of tooth structure removed and residual composite, which were statistically compared (t test) between the bur and laser groups.

RESULTS

Rotary instruments removed significantly more tooth structure than the laser in terms of mean depth (P = .0017) but not maximum depth (P = .0762). Although mean depth of tooth loss was smaller in the laser group, the area of tooth loss was significantly larger (P = .0004) because the rotary instrumentation left significantly more composite than the laser in terms of volume (P = .0104), mean depth (P = .0375), maximum depth (P = .0318), and area (P = .0056).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The erbium, chromium:yttrium-scandium-gallium-garnet laser was more selective in removing existing composite restorations than a rotary instrument because it removed less tooth structure and left behind less composite. Unintentional loss of tooth structure and unnoticeable residual composite are inevitable when removing existing composites. Erbium lasers are alternative means of composite removal that may be more selective than a rotary instrument.

Molecular fingerprinting delineates progenitor populations in the developing zebrafish enteric nervous system

BACKGROUND

To understand the basis of nervous system development, we must learn how multipotent progenitors generate diverse neuronal and glial lineages. We addressed this issue in the zebrafish enteric nervous system (ENS), a complex neuronal and glial network that regulates essential intestinal functions. Little is currently known about how ENS progenitor subpopulations generate enteric neuronal and glial diversity.

RESULTS

We identified temporally and spatially dependent progenitor subpopulations based on coexpression of three genes essential for normal ENS development: phox2bb, sox10, and ret. Our data suggest that combinatorial expression of these genes delineates three major ENS progenitor subpopulations, (1) phox2bb + /ret- /sox10-, (2) phox2bb + /ret + /sox10-, and (3) phox2bb + /ret + /sox10+, that reflect temporal progression of progenitor maturation during migration. We also found that differentiating zebrafish neurons maintain phox2bb and ret expression, and lose sox10 expression.

CONCLUSIONS

Our data show that zebrafish enteric progenitors constitute a heterogeneous population at both early and late stages of ENS development and suggest that marker gene expression is indicative of a progenitor's fate. We propose that a progenitor's expression profile reveals its developmental state: "younger" wave front progenitors express all three genes, whereas more mature progenitors behind the wave front selectively lose sox10 and/or ret expression, which may indicate developmental restriction. Developmental Dynamics 245:1081-1096, 2016. © 2016 Wiley Periodicals, Inc.

Issues in using whole slide imaging for diagnostic pathology: "routine" stains, immunohistochemistry and predictive markers

The traditional microscope, together with the "routine" hematoxylin and eosin (H & E) stain, remains the "gold standard" for diagnosis of cancer and other diseases; remarkably, it and the majority of associated biological stains are more than 150 years old. Immunohistochemistry has added to the repertoire of "stains" available. Because of the need for specific identification and even measurement of "biomarkers," immunohistochemistry has increased the demand for consistency of performance and interpretation of staining results. Rapid advances in the capabilities of digital imaging hardware and software now offer a realistic route to improved reproducibility, accuracy and quantification by utilizing whole slide digital images for diagnosis, education and research. There also are potential efficiencies in work flow and the promise of powerful new analytical methods; however, there also are challenges with respect to validation of the quality and fidelity of digital images, including the standard H & E stain, so that diagnostic performance by pathologists is not compromised when they rely on whole slide images instead of traditional stained tissues on glass slides.

Tissue engineered tumor models

Many research programs use well-characterized tumor cell lines as tumor models for in vitro studies. Because tumor cells grown as three-dimensional (3-D) structures have been shown to behave more like tumors in vivo than do cells growing in monolayer culture, a growing number of investigators now use tumor cell spheroids as models. Single cell type spheroids, however, do not model the stromal-epithelial interactions that have an important role in controlling tumor growth and development in vivo. We describe here a method for generating, reproducibly, more realistic 3-D tumor models that contain both stromal and malignant epithelial cells with an architecture that closely resembles that of tumor microlesions in vivo. Because they are so tissue-like we refer to them as tumor histoids. They can be generated reproducibly in substantial quantities. The bioreactor developed to generate histoid constructs is described and illustrated. It accommodates disposable culture chambers that have filled volumes of either 10 or 64 ml, each culture yielding on the order of 100 or 600 histoid particles, respectively. Each particle is a few tenths of a millimeter in diameter. Examples of histological sections of tumor histoids representing cancers of breast, prostate, colon, pancreas and urinary bladder are presented. Potential applications of tumor histoids include, but are not limited to, use as surrogate tumors for pre-screening anti-solid tumor pharmaceutical agents, as reference specimens for immunostaining in the surgical pathology laboratory and use in studies of invasive properties of cells or other aspects of tumor development and progression. Histoids containing nonmalignant cells also may have potential as "seeds" in tissue engineering. For drug testing, histoids probably will have to meet certain criteria of size and tumor cell content. Using a COPAS Plus flow cytometer, histoids containing fluorescent tumor cells were analyzed successfully and sorted using such criteria.

Standardization in immunohistochemistry: the role of antigen retrieval in molecular morphology

Molecular morphology seeks to integrate the traditional morphologic criteria of surgical pathology with immunohistochemical and in situ hybridization techniques that allow demonstration of a variety of molecules, proteins, RNA and DNA in a tissue section. While immunohistochemistry has proven to be successful for demonstrating lineage related biomarkers of value for diagnosis and classification of tumors, concerns have been raised periodically about validation of reagents, overall reproducibility of the staining method, and interpretation of results. These concerns have been heightened by the burgeoning interest in prognostic markers, where the question extends beyond a relatively simple positive or negative result to an absolute need for quantification of the staining result; not only is it positive, but how much is there? In this presentation at the Annual Meeting of the Biological Stain Commission in June, 2005, I advocate a total test approach that requires systematic attention to pre-analytic, analytic, and post-analytic issues. The approach encompasses all aspects of test performance from specimen acquisition, through fixation, antigen retrieval, processing, staining, interpretation, and reporting of results. A similar systematic approach also may be adopted for in situ hybridization methods, which have performance requirements that in many ways parallel immunohistochemistry.

Quantification of immunohistochemistry--issues concerning methods, utility and semiquantitative assessment II

Immunohistochemistry is entering its fourth decade of use on formalin-fixed paraffin-embedded tissues. Over this period the method has evolved to become a major part of the practice of diagnostic surgical pathology worldwide. From the beginning immunohistochemistry has been adapted to provide a range of markers of cell lineage and tissue type, with particular application to the diagnosis and classification of tumours. In this modality immunohistochemical methods were employed simply as 'special stains', the results of which were evaluated qualitatively by the pathologist, as for any other stain. More recently, attention has shifted to the demonstration of prognostic markers in tumour cells, driven by the advent of molecular biology and the discovery of numerous regulatory molecules, coupled with manufacture of the corresponding specific antibodies. Immunohistochemistry has rapidly adapted to this new use, but in so doing the demand for quantification has become paramount; it is no longer enough that the 'stain' is there; rather it is a question of 'How much is there?'. This review explores the limitations of immunohistochemistry when employed in a semiquantitative mode, and explores the possibility of fulfilling the full potential of immunohistochemistry, as a true quantitative immunoassay applied in a tissue section environment.

The circadian rhythm of angina pectoris

Analysis of diary card data from 33,999 angina attacks recorded in 1,022 patients with chronic stable angina showed a clear circadian pattern to the frequency of angina that resembles patterns previously described for myocardial infarction and sudden cardiac death, with a peak in the morning. The majority of angina attacks were preceded by physical exertion and the circadian pattern was more pronounced for exertional angina than nonexertional angina. In this study, treatment with beta-blockers did not prevent the morning peak of angina attacks.

Assessment of the elution of charcoal, cellulose acetate, and other particles from cigarettes with charcoal and activated charcoal/resin filters

This experiment was designed to study the release of cellulose acetate fibers, charcoal, and other particles from cigarettes with charcoal and activated charcoal/resin filters. For the first time in such studies, efforts were made to identify the particles that were eluted using other analytical techniques in addition to light microscopy. Other corrective measures were also implemented. During the studies it was found that trimming of larger filters to fit smaller filter housings introduced cellulose acetate-like particles from the fibers of the filter material. Special, custom made-to-fit filters were used instead. Tools such as forceps that were used to retrieve filters from their housings were also found to introduce fragments onto the filters. It is believed that introduction of such debris may have accounted for the very large number of cellulose acetate and charcoal particles that had been reported in the literature. Use of computerized particle-counting microscopes appeared to result in excessive number of particles. This could be because the filter or smoke pads used for such work do not have the flat and level surfaces ideal for computerized particle-counting microscopes. At the high magnifications that the pads were viewed for particles, constant focusing of the microscope would be essential. It was also found that determination of total particles by using extrapolation of particle count by grid population usually gave extremely high particle counts compared to the actual number of particles present. This could be because particle distributions during smoking are not uniform. Lastly, a less complex estimation of the thickness of the particles was adopted. This and the use of a simple mathematical conversion coupled with the Cox equation were utilized to assess the aerodynamic diameters of the particles. Our findings showed that compared to numbers quoted in the literature, only a small amount of charcoal, cellulose acetate shards, and other particles are released. It was also shown that those particles would have a low likelihood of reaching the lung.

Different localization of dendritic cell reservoirs in human immunodeficiency virus-1 subtype B versus subtype E-infected lymph nodes

The presence of p24 protein was studied in lymph nodes from human immunodeficiency virus (HIV)-positive patients affected by persistent generalized lymphadenopathy. Paraffin-embedded lymph node sections from 50 HIV-1 subtype E-infected lymph nodes from patients in Thailand and 25 HIV-1 presumably subtype B-infected lymph nodes from patients in the United States were immunostained with p24 HIV major core and capsid monoclonal antibodies using the streptavidin-biotin immunoperoxidase technique. Positivity for HIV p24 protein was detected in 20 of 22 HIV-1 subtype B infected nodes in which lymphoid follicles were present, with p24 staining demonstrating a reticular pattern within the germinal centers. Interestingly, no case from 50 clade E-infected lymph nodes containing lymphoid follicles had such a reticular pattern in the germinal centers. This difference could be explained by differential infection of subsets of dendritic cells by the two HIV-1 clades, or perhaps by different routes of initial HIV-1 transmission.

Molecular morphology of Hodgkin lymphoma

No other disease entity has provided greater impetus for the development of the concept of "molecular morphology" than Hodgkin lymphoma. Efforts to understand the etiology of this enigmatic disease have stimulated the application and refinement of almost every mode of biomedical scientific exploration. Notwithstanding the vast amount of data generated, much is still unknown about this remarkable disease, serving as an ongoing inducement to the development and application of new technologies for the analysis of cells and molecules in a morphologic environment.

Antigen retrieval techniques: current perspectives

Development of the antigen retrieval (AR) technique, a simple method of boiling archival paraffin-embedded tissue sections in water to enhance the signal of immunohistochemistry (IHC), was the fruit of pioneering efforts guided by the philosophy of rendering IHC applicable to routine formalin-fixed, paraffin-embedded tissues for wide application of IHC in research and clinical pathology. On the basis of thousands of articles and many reviews, a book has recently been published that summarizes basic principles for practice and further development of the AR technique. Major topics with respect to several critical issues, such as the definition, application, technical principles, and further studies of the AR technique, are highlighted in this article. In particular, a further application of the heat-induced retrieval approach for sufficient extraction of nucleic acids in addition to proteins, and standardization of routine IHC based on the AR technique in terms of a test battery approach, are also addressed. Furthermore, understanding the mechanism of the AR technique may shed light on facilitating the development of molecular morphology.

Antigen retrieval immunohistochemistry and molecular morphology in the year 2001

The impact of the antigen retrieval (AR) technique upon diagnostic immunohistochemistry (IHC) and upon research has been demonstrated by numerous of articles and more than a dozen major reviews. The specific aim of this survey of the field is to examine potential new approaches to retrieval of nucleic acid and protein from archival paraffin-embedded tissue for molecular biology-based diagnostic procedures that form the basis of the emerging field of molecular morphology. Any new approach must incorporate the principles of standardization and improved reproducibility. The ultimate goal will be to understand the mechanisms of fixation (by formalin) and "unfixation" (by AR). In the interim, the diligent application of practical procedures that have been shown to be tried and true is the least that we must demand from ourselves and our laboratories.

Evaluation of JPEG and wavelet compression of body CT images for direct digital teleradiologic transmission

PURPOSE

To determine acceptable levels of JPEG (Joint Photographic Experts Group) and wavelet compression for teleradiologic transmission of body computed tomographic (CT) images.

MATERIALS AND METHODS

A digital test pattern (Society of Motion Picture and Television Engineers, 512 x 512 matrix) was transmitted after JPEG or wavelet compression by using point-to-point and Web-based teleradiology, respectively. Lossless, 10:1 lossy, and 20:1 lossy ratios were tested. Images were evaluated for high- and low-contrast resolution, sensitivity to small signal differences, and misregistration artifacts. Three independent observers who were blinded to the compression scheme evaluated these image quality measures in 20 clinical cases with similar levels of compression.

RESULTS

High-contrast resolution was not diminished with any tested level of JPEG or wavelet compression. With JPEG compression, low-contrast resolution was not lost with 10:1 lossy compression but was lost at 3% modulation with 20:1 lossy compression. With wavelet compression, there was loss of 1% modulation with 10:1 lossy compression and loss of 5% modulation with 20:1 lossy compression. Sensitivity to small signal differences (5% and 95% of the maximal signal) diminished only with 20:1 lossy wavelet compression. With 10:1 lossy compression, misregistration artifacts were mild and were equivalent with JPEG and wavelet compression. Qualitative clinical findings supported these findings.

CONCLUSION

Lossy 10:1 compression is suitable for on-call electronic transmission of body CT images as long as original images are subsequently reviewed.

Kimura's disease with oral ulcers: response to pentoxifylline

We describe a man with Kimura's disease whose presentation included lymphadenopathy and cutaneous nodules, but was most distinctive for painful oral ulcerations. His lesions showed an initially moderate, but ultimately minimal response to monthly triamcinolone injections. With oral pentoxyifylline, he showed resolution of all of his lesions for 14 months. On cessation of his treatment, his disease flared for 3 months. When pentoxyifylline was restarted, his lesions regressed again within 4 weeks. We review the literature on Kimura's disease.

Prognostic factors in colorectal cancer. College of American Pathologists Consensus Statement 1999

BACKGROUND

Under the auspices of the College of American Pathologists, the current state of knowledge regarding pathologic prognostic factors (factors linked to outcome) and predictive factors (factors predicting response to therapy) in colorectal carcinoma was evaluated. A multidisciplinary group of clinical (including the disciplines of medical oncology, surgical oncology, and radiation oncology), pathologic, and statistical experts in colorectal cancer reviewed all relevant medical literature and stratified the reported prognostic factors into categories that reflected the strength of the published evidence demonstrating their prognostic value. Accordingly, the following categories of prognostic factors were defined. Category I includes factors definitively proven to be of prognostic import based on evidence from multiple statistically robust published trials and generally used in patient management. Category IIA includes factors extensively studied biologically and/or clinically and repeatedly shown to have prognostic value for outcome and/or predictive value for therapy that is of sufficient import to be included in the pathology report but that remains to be validated in statistically robust studies. Category IIB includes factors shown to be promising in multiple studies but lacking sufficient data for inclusion in category I or IIA. Category III includes factors not yet sufficiently studied to determine their prognostic value. Category IV includes factors well studied and shown to have no prognostic significance.

MATERIALS AND METHODS

The medical literature was critically reviewed, and the analysis revealed specific points of variability in approach that prevented direct comparisons among published studies and compromised the quality of the collective data. Categories of variability recognized included the following: (1) methods of analysis, (2) interpretation of findings, (3) reporting of data, and (4) statistical evaluation. Additional points of variability within these categories were defined from the collective experience of the group. Reasons for the assignment of an individual prognostic factor to category I, II, III, or IV (categories defined by the level of scientific validation) were outlined with reference to the specific types of variability associated with the supportive data. For each factor and category of variability related to that factor, detailed recommendations for improvement were made. The recommendations were based on the following aims: (1) to increase the uniformity and completeness of pathologic evaluation of tumor specimens, (2) to enhance the quality of the data needed for definitive evaluation of the prognostic value of individual prognostic factors, and (3) ultimately, to improve patient care.

RESULTS AND CONCLUSIONS

Factors that were determined to merit inclusion in category I were as follows: the local extent of tumor assessed pathologically (the pT category of the TNM staging system of the American Joint Committee on Cancer and the Union Internationale Contre le Cancer [AJCC/UICC]); regional lymph node metastasis (the pN category of the TNM staging system); blood or lymphatic vessel invasion; residual tumor following surgery with curative intent (the R classification of the AJCC/UICC staging system), especially as it relates to positive surgical margins; and preoperative elevation of carcinoembryonic antigen elevation (a factor established by laboratory medicine methods rather than anatomic pathology). Factors in category IIA included the following: tumor grade, radial margin status (for resection specimens with nonperitonealized surfaces), and residual tumor in the resection specimen following neoadjuvant therapy (the ypTNM category of the TNM staging system of the AJCC/UICC). (ABSTRACT TRUNCATED)

Topical ALA-photodynamic therapy for the treatment of acne vulgaris

Topical aminolevulinic acid is converted into a potent photosensitizer, protoporphyrin, in human hair follicles and sebaceous glands. Photodynamic therapy with topical aminolevulinic acid was tested for the treatment of acne vulgaris, in an open-label prospective human study. Each of 22 subjects with acne on the back was treated in four sites with aminolevulinic acid plus red light, aminolevulinic acid alone, light alone, and untreated control. Half of the subjects were treated once; half were treated four times. Twenty percent topical aminolevulinic acid was applied with 3 h occlusion, and 150 J per cm2 broad-band light (550-700 nm) was given. Sebum excretion rate and auto-fluorescence from follicular bacteria were measured before, and 2, 3, 10, and 20 wk after, treatment. Histologic changes and protoporphyrin synthesis in pilosebaceous units were observed from skin biopsies. Aminolevulinic acid plus red light caused a transient acne-like folliculitis. Sebum excretion was eliminated for several weeks, and decreased for 20 wk after photodynamic therapy; multiple treatments caused greater suppression of sebum. Bacterial porphyrin fluorescence was also suppressed by photodynamic therapy. On histology, sebaceous glands showed acute damage and were smaller 20 wk after photodynamic therapy. There was clinical and statistically significant clearance of inflammatory acne by aminolevulinic acid plus red light, for at least 20 wk after multiple treatments and 10 wk after a single treatment. Transient hyperpigmentation, superficial exfoliation, and crusting were observed, which cleared without scarring. Topical aminolevulinic acid plus red light is an effective treatment of acne vulgaris, associated with significant side-effects. Aminolevulinic acid plus red light causes phototoxicity to sebaceous follicles, prolonged suppression of sebaceous gland function, and apparent decrease in follicular bacteria after photodynamic therapy. Potentially, aminolevulinic acid plus red light may be useful for some patients with acne.

Prognostic factors in colorectal cancer. College of American Pathologists Consensus Statement 1999

BACKGROUND

Under the auspices of the College of American Pathologists, the current state of knowledge regarding pathologic prognostic factors (factors linked to outcome) and predictive factors (factors predicting response to therapy) in colorectal carcinoma was evaluated. A multidisciplinary group of clinical (including the disciplines of medical oncology, surgical oncology, and radiation oncology), pathologic, and statistical experts in colorectal cancer reviewed all relevant medical literature and stratified the reported prognostic factors into categories that reflected the strength of the published evidence demonstrating their prognostic value. Accordingly, the following categories of prognostic factors were defined. Category I includes factors definitively proven to be of prognostic import based on evidence from multiple statistically robust published trials and generally used in patient management. Category IIA includes factors extensively studied biologically and/or clinically and repeatedly shown to have prognostic value for outcome and/or predictive value for therapy that is of sufficient import to be included in the pathology report but that remains to be validated in statistically robust studies. Category IIB includes factors shown to be promising in multiple studies but lacking sufficient data for inclusion in category I or IIA. Category III includes factors not yet sufficiently studied to determine their prognostic value. Category IV includes factors well studied and shown to have no prognostic significance.

MATERIALS AND METHODS

The medical literature was critically reviewed, and the analysis revealed specific points of variability in approach that prevented direct comparisons among published studies and compromised the quality of the collective data. Categories of variability recognized included the following: (1) methods of analysis, (2) interpretation of findings, (3) reporting of data, and (4) statistical evaluation. Additional points of variability within these categories were defined from the collective experience of the group. Reasons for the assignment of an individual prognostic factor to category I, II, III, or IV (categories defined by the level of scientific validation) were outlined with reference to the specific types of variability associated with the supportive data. For each factor and category of variability related to that factor, detailed recommendations for improvement were made. The recommendations were based on the following aims: (1) to increase the uniformity and completeness of pathologic evaluation of tumor specimens, (2) to enhance the quality of the data needed for definitive evaluation of the prognostic value of individual prognostic factors, and (3) ultimately, to improve patient care.

RESULTS AND CONCLUSIONS

Factors that were determined to merit inclusion in category I were as follows: the local extent of tumor assessed pathologically (the pT category of the TNM staging system of the American Joint Committee on Cancer and the Union Internationale Contre le Cancer [AJCC/UICC]); regional lymph node metastasis (the pN category of the TNM staging system); blood or lymphatic vessel invasion; residual tumor following surgery with curative intent (the R classification of the AJCC/UICC staging system), especially as it relates to positive surgical margins; and preoperative elevation of carcinoembryonic antigen elevation (a factor established by laboratory medicine methods rather than anatomic pathology). Factors in category IIA included the following: tumor grade, radial margin status (for resection specimens with nonperitonealized surfaces), and residual tumor in the resection specimen following neoadjuvant therapy (the ypTNM category of the TNM staging system of the AJCC/UICC). (ABSTRACT TRUNCATED)

Laser ignition of traumatically embedded firework debris

BACKGROUND AND OBJECTIVE

The Q-switched ruby laser (QSRL) has a good track record for traumatic tattoo removal. An unusual case of QSRL-treatment of a traumatic tattoo composed of firework debris is presented.

STUDY DESIGN/PATIENT AND METHOD

A young man's traumatic tattoo, composed of firework debris, underwent QSRL ablation at 4-7 J/cm2 (pulse width 5 mm; duration 20 ns).

RESULTS

Each test pulse produced visible sparks and focal projectile ejection of skin with pox-like scar formation.

CONCLUSION

Caution is advised when using the QSRL for the treatment of traumatic tattoos composed of potentially combustible debris.

CO2 laser resurfacing of psoriatic plaques: a pilot study

BACKGROUND AND OBJECTIVE

Laser resurfacing can precisely remove epidermis and papillary dermis, sites pivotal to the pathogenesis of psoriasis. Our objective was to determine the efficacy and safety of superficially ablating carbon dioxide (CO2) lasers for treating isolated, recalcitrant psoriatic plaques.

MATERIALS AND METHODS

Twelve adult subjects with stable, plaque-type psoriasis were recruited. In six volunteers, the quadrants received different numbers of passes with a 60 microsec pulsed CO2 (Tru-Pulse) laser. In the remaining patients, one quadrant underwent curettage prior to resurfacing, the second resurfacing with a scanned continuous wave (Sharplan Silktouch) CO2 laser and the last curettage alone.

RESULTS

Despite clinical and histological evidence of complete ablation of the epidermis and papillary dermis, most quadrants recurred within 8 weeks. Surprisingly, two patients showed no recurrence after 4 months.

CONCLUSION

Ablation of the entire epidermis and papillary dermis with either pulsed or scanned CO2 lasers appears generally ineffective in treating recalcitrant psoriatic plaques, although the clearing seen in two patients suggests potentially successful future research directions.

LEA.135 expression: an independent and favorable prognostic biomarker for patients with primary invasive breast cancer

The prognostic significance of LEA.135 expression, detected by immunohistochemistry in formalin-fixed and paraffin-embedded tissue sections, was evaluated and compared with the widely utilized clinicopathological parameters for patients with primary invasive breast carcinomas. Pathological parameters such as tumor size, histological tumor type, histological grade, nuclear grade, lymph node (LN) status, bone marrow (BM) status, as well as age of patient at initial diagnosis together with follow-up in years were available for this group of patients (n = 178). Among these parameters, tumor size, histological tumor type, histological grade, LN status, and BM status were individually and significantly associated with increased probability of recurrence by univariate analysis. By multivariate analysis, however, only tumor size, LN status, and BM status remained statistically significant. LEA.135-positive patients showed a statistically significant probability of not recurring (77 +/- 5% at 5 years after surgery) compared with patients who were LEA. 135-negative (49 +/- 6% at 5 years after surgery) (log-rank p < 0. 001). Furthermore, the association remained statistically significant by multivariate analysis (log-rank p = 0.019), demonstrating that LEA.135 expression independently and significantly identified breast cancer patients with favorable clinical outcome. In addition, there was a statistically significant association between loss of LEA.135 expression and poor prognosis when patients were stratified by pathological parameters. Furthermore, a subgroup of patients who were LEA. 135-positive/LN-negative experienced a decreased rate of recurrence compared with those who were LEA.135-negative/LN-negative (16% vs. 27%, respectively). A similar result was also obtained when BM-negative patients were stratified on the basis of LEA. 135-positive or LEA.135-negative subgroups for recurrence (18% vs. 43%, respectively). Most interestingly, the patients whose cancer cells were LEA.135-positive/LN-positive experienced a much lower rate of recurrence than those whose cells were LEA. 135-negative/LN-positive (29% vs. 57%, respectively). The results clearly demonstrate that LEA.135 expression was a significantly independent and favorable prognostic marker for patients with primary invasive breast carcinoma by both univariate and multivariate analyses.

308-nm excimer laser for the treatment of psoriasis: a dose-response study

OBJECTIVE

To determine the dose-response relationship of excimer laser-generated 308-nm UV-B radiation for treating psoriasis.

DESIGN

Pilot study with a before-after design.

SETTING

A university dermatology service.

PATIENTS

Thirteen consecutive patients with at least 4 large, stable psoriasis plaques.

INTERVENTIONS

Excimer laser-generated 308-nm UV-B radiation was given to each of 4 plaques, which received 1, 2, 4, and 20 treatments, respectively. Untreated areas within each plaque served as controls. Within each plaque, 8 doses based on multiples of a predetermined minimal erythema dose (MED) were tested in distinct sites. The multiples were 0.5 and 1 (low dose); 2, 3, 4, and 6 (medium dose); and 8 and 16 (high dose). At every treatment, the dose for each site remained fixed at the same MED multiple. A psoriasis severity index score was determined for each area before, every 2 weeks during, and 2 and 4 months after treatment.

RESULTS

The mean+/-SD MED was 203.03+/-57.84 mJ/ cm2. Treatment with high fluences produced significantly better results than that with medium and low fluences at weeks 4, 6, 8, and 10 (P<.05). At 4 months' follow-up, all sites that received low or medium fluences had recurrences, whereas those that underwent a single treatment at 8 and 16 MED multiples remained in remission.

CONCLUSIONS

With 308-nm UV-B radiation generated by an excimer laser, it is possible to clear psoriasis with as little as 1 treatment with moderately long remission. In contrast to traditional phototherapy techniques, this handheld excimer laser UV-B therapy is selectively directed toward lesional skin, thus sparing the surrounding normal skin from unnecessary radiation exposure. Treatment of other inflammatory diseases and limited psoriasis seems reasonable to pursue with this modality.

LEA.135 expression: its comparison with other prognostic biomarkers for patients with primary breast carcinoma

The purpose of this retrospective study was to examine the prognostic value of expression of luminal epithelial antigen (LEA.135) for recurrence and overall survival of patients with primary invasive breast carcinoma by both univariate and multivariate analyses. The possible prognostic value of LEA.135 was also compared with some widely utilized prognostic biomarkers such as c-erbB 2, topoisomerase II.alpha (TPII.alpha), MIB 1, estrogen receptor (ER) and progesterone receptor (PR), as well as age of the patients and clinicopathologic parameters. The study was carried out by immunohistochemical methods on formalin-fixed/paraffin-embedded tissue sections in a series of 225 patients with median follow-up of 8.5 years. Prognostic significance of the biomarkers was determined by two-sided p value. In this series of patients, among the age and clinicopathologic parameters, only age, was significantly associated with a decreased overall survival (logrank p = 0.027). Among the prognostic biomarkers, TPII a expression at high (> 50% positive cells) or moderate (6-50% positive cells) level was associated with an increased rate of recurrence (logrank p < 0.001). However, the association of TPII.alpha expression with a decreased overall survival failed to reach a statistically significance. Expression of c-erbB 2 showed a trend of being associated with an increased probability of recurrence, but the association did not reach statistical significance. The remaining biomarkers were not associated with either the probability of recurrence or overall survival. LEA.135 expression was observed in 163 (72.4%) of the 225 patients. The patients with high (> 50% positive cells) or moderate (6-50% positive cells) level of LEA.135-positive cancer cells showed a significantly decreased probability of recurrence (logrank p < 0.001) and an increased overall survival (logrank p < 0.001) compared with those with LEA.135-negative cancer cells. The association remained significant by multivariate analysis for recurrence (likelihood ratio test p < 0.001) and overall survival (likelihood ratio test p < 0.001) when assessed with other prognostic parameters. Furthermore, the combination of LEA.135 with other prognostic biomarkers stratified four subgroups of patients with distinct clinical outcome. The subgroup of patients who were LEA.135+/TPII.alpha- showed the lowest probability of recurrence and the longest overall survival compared with those who were LEA.135-/TPII.alpha+ (logrank p < 0.001). Interestingly, the patients whose cancer cells were LEA.135+/TPII.alpha+, LEA.135+ MIB.1+ or LEA.135+/c-erbB 2+ experienced a decreased probability of recurrence and an increased overall survival compared with those with LEA.135-/TPII.alpha+, LEA.135- MIB.1+ or LEA.135-/c-erbB 2+ (logrank p < 0.001). The results demonstrated that LEA.135 is an independent and favorable prognostic biomarker for patients with primary invasive breast carcinoma, that the loss of LEA.135 expression is associated with aggressive phenotype of cancer cells during the breast cancer progression, and that its continued expression seems to override the adverse effects of expression of an oncogene or cell proliferation-associated molecules.

Pendulaser carbon dioxide resurfacing laser versus electrodesiccation with curettage in the treatment of isolated, recalcitrant psoriatic plaques

BACKGROUND

Treatment of recalcitrant psoriatic plaques located on certain areas of the body remains problematic despite the many therapeutic options available.

OBJECTIVE

This study was conducted to determine the efficacy of Pendulaser carbon dioxide (CO(2)) resurfacing laser to that of electrodesiccation with curettage in the treatment of recalcitrant psoriatic plaques.

METHODS

A single psoriatic plaque was divided into thirds, one part treated with CO(2) resurfacing laser, another with electrodesiccation and curettage, and the third left untreated. The psoriatic epidermis and papillary dermis were removed by the two treatment modalities.

RESULTS

CO(2) resurfacing laser and electrodesiccation with curettage produced similar therapeutic effects in terms of improvement of psoriasis and were significantly better than the control 4 months later, but not at 6 months.

CONCLUSION

For limited recalcitrant psoriatic plaques, CO(2) resurfacing laser and electrodesiccation with curettage may provide an alternative short-term treatment; however, caution must be exercised and the moderately high risk of scarring carefully weighed against the potential benefits.

Hand and foot PUVA soaks: an audit of the Massachusetts General Hospital's experience from 1994 to 1998

Palmoplantar psoriasis and eczema can be chronic recalcitrant dermatoses. Oral psoralen plus ultraviolet A (PUVA) has proven effective for these, but has a number of unwanted side effects. Previous studies have shown that regional PUVA therapy using the 8-methoxypsoralen (8-MOP) soak method followed by immediate UVA irradiation is also beneficial and well tolerated. The purpose of this audit was to determine the efficacy of hand and foot PUVA soaks by reviewing the experience of the Massachusetts General Hospital's Phototherapy Unit with this treatment modality. Phototherapy records of all patients who underwent hand and foot PUVA soaks from 1994 to 1998 were reviewed. Details regarding the treatment procedure, patient compliance, patient response and incidence of side effects were noted and summarized. Of the 56 patients who underwent at least 20 treatments, 29% had excellent response, 42% had minimal to moderate response, and 29% had poor response. The average number of treatments to induce clearing was 41. The average maximum treatment dose at clearing was 5.85 J/cm2, while the average cumulative dose to achieve clearing was 267.17 J/cm2. 8-MOP PUVA soak therapy is quite useful for chronic hand and foot dermatoses. Patient compliance must be emphasized to obtain favorable results.

Temperatures reached inside stand-up ultraviolet treatment boxes

Heat generated within ultraviolet treatment units can exacerbate eczema. To document the actual temperature changes within the treatment units, we measured the air temperatures in standard stand-up psoralen plus ultraviolet A (PUVA), narrowband ultraviolet B (UVB), broadband UVB, and combination UVA/UVB cabinets using a thermocouple thermometer. For the latter unit, we also measured the air temperatures with and without ventilation systems, and actual skin temperatures on individuals undergoing light treatment. The air temperatures rose significantly in all the treatment units, more so with PUVA and narrowband UVB boxes, and were highest with the ventilation systems shut off. Skin temperatures also rose significantly, but less dramatically. Ventilation is essential in maintaining comfortable temperatures within ultraviolet treatment units.

Analysis of telomerase activity in ovarian cystadenomas, low-malignant-potential tumors, and invasive carcinomas

OBJECTIVE

Inappropriate telomerase expression has been reported to be associated with the development and/or progression of malignancies. Therefore, the purpose of the study was to determine and evaluate the levels of telomerase activity in normal ovary, cystadenomas, low-malignant-potential tumors, and carcinomas of the ovary.

METHODS

In the present study, telomerase activity was examined in frozen tissue specimens of normal ovary (n = 6), ovarian cystadenomas (n = 13), ovarian low-malignant-potential (LMP) tumors (n = 12), and ovarian invasive carcinomas (n = 81). Clinicopathological information including age at diagnosis, histological grade, FIGO stage, presence of distant metastasis at diagnosis, and residual disease was available for all patients with ovarian carcinomas (n = 81). Telomerase activity was assessed by the telomeric repeat amplification protocol (TRAP). Arbitrary values were assigned to processivity of telomerase activities based on the molecular weights of the telomeric repeat DNA ladders, and were graded as "negative," "moderate" (< or =99 bp), or "high" (>100 bp) activities. The specificity of telomerase activity was determined by the pretreatment of telomerase-positive control or tumor samples with RNase that led to the abolition of the activity. In addition, to determine the possibility of false negativity due to the presence of telomerase inhibitors, TRAP assay was performed on each of the telomerase-negative specimens by mixing them individually with the telomerase-positive control.

RESULTS

Telomerase activity in the progression of ovarian carcinogenesis was evaluated. In comparison with normal ovary/cystadenoma (32%), a much higher frequency of the moderate activity was observed in LMP tumors (67%) or invasive carcinomas (57%), suggesting a close association between the latter two categories. The results reflect a subpopulation of telomerase-positive LMP tumor cells with the potential to develop invasive carcinomas. None of the specimens of the benign or LMP tumors exhibited high activity. In contrast, 18% of ovarian invasive carcinomas showed high telomerase activity (P = 0.013, Fisher exact test) and further 57%, moderate activity (75% in all). A statistically significant difference was observed in the expression of telomerase activity between normal ovary/benign cystadenomas and ovarian invasive carcinomas (P = 0.001, chi(2) test).

CONCLUSIONS

The study showed a high prevalence of telomerase activity in LMP tumors or invasive carcinomas, the high levels of telomerase activity being associated exclusively with the invasive ovarian carcinomas. Therefore, the levels of processivity of telomerase activity and evidence of its statistically significant association with ovarian carcinoma suggest its role in the progression of ovarian carcinogenesis.

Characterization of photosensitivity in the Smith-Lemli-Opitz syndrome: a new congenital photosensitivity syndrome

Photosensitivity has recently been reported as a feature of the Smith-Lemli-Opitz syndrome (SLO). The aim of this study was to establish the photobiological features of this disorder and to examine the hypothesis that the photosensitivity is caused by the high levels of 7-dehydrocholesterol found in SLO. All known cases of SLO in the U.K. were reviewed and clinical details of photosensitivity were recorded in detail. The action spectrum of the photosensitive eruption was defined by monochromator light testing. Thirteen of the 23 subjects (57%) had severe photosensitivity, and in 10 there was no photosensitivity. No correlation was identified between levels of 7-dehydrocholesterol and severity of photosensitivity, suggesting that the photosensitivity in SLO is not caused by a direct phototoxic effect mediated by 7-dehydrocholesterol. A novel pattern of photosensitivity was observed, with onset of a sunburn-like erythema on sun-exposed skin within minutes of sun exposure, which persisted in most cases for up to 24-48 h before fading. Monochromator light testing in three subjects showed an ultraviolet (UV) A-mediated photosensitivity eruption with greatest photosensitivity at 350 nm. Photosensitivity is a common and prominent feature of SLO and appears to be UVA-mediated. Elucidation of its biochemical basis may provide insight into normal cutaneous protective mechanisms against UVA-induced photodamage, and also sun sensitivity in general.

Telomerase activity: comparison between fine-needle aspiration and biopsy specimens for the detection of tumor cells

BACKGROUND

The purpose of the current study was to determine telomerase activity as a sensitive biomarker for the detection of malignant cells in fine-needle aspiration (FNA) specimens.

METHODS

FNA specimens with parallel samples of fresh tumor tissue were obtained from surgical specimens after surgical excision. Using a polymerase chain reaction-based telomeric repeat amplification protocol (TRAP) assay, telomerase activity was determined systematically in FNA specimens (n = 21) and corresponding available tissue biopsy specimens (n = 16) containing malignant cells. In addition to a case of myelolipoma, normal counterparts for 3 of 16 cancer cases, including both biopsy and FNA specimens, also were available for the determination of telomerase activity.

RESULTS

Telomerase activity was observed in 14 of 16 of the FNA specimens (88%) and 15 of 16 of the corresponding biopsy specimens (94%). Telomerase activity was detected in both the biopsy specimen and the corresponding FNA specimen, with one exception (a case of mucinous adenocarcinoma of the cecum). In contrast, specimens from three normal tissue biopsies and FNA specimens of normal tissue adjacent to the malignant lesions, as well as the myelolipoma, exhibited no telomerase activity. It is interesting to note that both tissue biopsy specimens and FNA specimens from a patient with high grade sarcoma were negative for telomerase activity. The examination of hematoxylin and eosin-stained adjacent tissue biopsy sections or FNA smears revealed similar low populations of lymphocytes, including those cases that were negative for telomerase activity. There was agreement in the detection of telomerase activity between tissue biopsies and their corresponding FNA specimens in 15 of the 16 patients, indicating a 94% concordance rate (95% confidence interval, 70%, 98%).

CONCLUSIONS

The results of the current study clearly suggest that the telomerase activity in FNA specimens was comparable to that of their corresponding biopsy specimens, and that this activity was associated with the presence of malignant cells. The TRAP assay has potential for use in the detection of malignant cells in FNA specimens, particularly cases in which the cytology is not characteristically malignant and/or is present in insufficient numbers. Cancer (Cancer Cytopathol)

Photosensitivity in the Smith-Lemli-Opitz syndrome: the US experience of a new congenital photosensitivity syndrome

Photosensitivity has been briefly mentioned in several publications on the Smith-Lemli-Opitz (SLO) syndrome, an autosomal recessive mental retardation syndrome. We conducted a questionnaire-based survey to determine the incidence and main features of photosensitivity in SLO. We confirmed a high incidence, and initial evidence suggests that SLO may be the first example of an inherited photosensitivity disorder in which sensitivity to UVA is common.

Purification and characterization of a Hodgkin's and B cell-associated glycoprotein

A glycoprotein (BLA.36), expressed on the plasma membrane of Hodgkin's cells and also on normal and malignant B lymphocytes and histiocytes, was identified by reaction with a monoclonal antibody. BLA.36 was not detectable on other hematopoietic, carcinoma or melanoma cell lines. BLA.36 was purified to homogeneity by extracting proteins from a Hodgkin's cell line (HDLM-3), followed by immunoaffinity chromatography, utilizing immobilized anti-BLA.36 antibody, and gel filtration on Sephacryl S-100 in the presence of protein dissociating agents. The purified component yielded a single band on sodium dodecyl sulphate/polyacrylamide gel electrophoresis under both non-reducing and reducing conditions, and closely related three isotypes of similar molecular weight and with the apparent isoelectric points that ranged from 5.0 to 5.2 on two-dimensional gel electrophoresis. The purified BLA.36 reacted with the original specific antibody, on both one- or two-dimensional gel electrophoresis, suggesting that antigenic determinant was not adversely affected during purification procedure. Competitive immunoprecipitation analyses and the determination of N-terminus sequence of the first 13 amino acid residues suggest that BLA.36 is unrelated to other known Hodgkin's or hematopoietic cell antigens. Finally, significance of BLA.36 expression on the growth of BLA.36-positive cell lines was studied. Blocking of BLA.36 with anti-BLA.36 antibody led to the in vitro growth-inhibition of BLA.36-positive cell lines. The antibody pre-absorbed with the purified BLA.36 was unable to exert growth-inhibition, demonstrating the specificity of reaction. In addition, the treatment of the BLA.36-positive cell lines with differentiation-inducing agent, alpha-interferon (alpha-IFN), down-regulated BLA.36 expression and also showed in vitro growth-inhibition of BLA.36-positive cell lines. Taken together, these results suggest a growth-related function of BLA.36.