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The luminol test has been used for over 60 years by forensic investigators for presumptive identification of blood and visualization of blood splatter patterns. Multiple studies have estimated the limit of detection (LD) for bloodstains when luminol is employed, with results ranging from 100× to 5,000,000× dilute. However, these studies typically have not identified and controlled important experimental variables which may affect the luminol LD for bloodstains. Without control of experimental parameters in the laboratory, variables which affect the potential of presumptive bloodstain test methods remain largely unknown, and comparisons required to establish new, more powerful detection methods are simply impossible. We have developed a quantitative method to determine the relationship between the amount of blood present and its reaction with luminol by measuring, under controlled conditions, the resulting chemiluminescent intensity with a video camera, combined with processing of the digital intensity data. The method resulted in an estimated LD for bloodstains on cotton fabric at ∼200,000× diluted blood with a specific luminol formulation. Although luminol is the focus of this study, the experimental protocol used could be modified to study effects of variables using other blood detection reagents., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: The term primary lymph node gastrinoma was first used to describe a group of patients with gastrin-producing tumors present in lymph nodes located in a well-defined anatomic region. The patients had no known primary tumors in the pancreas or gastrointestinal tract and had disease-free survival for up to 18 years. The anatomic region in question has a triangular shape that extends from the cystic and common bile ducts to the second and third portion of the duodenum and the neck and body of the pancreas. The term gastrinoma triangle was coined to identify the area; in addition, it was postulated that lymph nodes located in the gastrinoma triangle normally contained neuroendocrine cells capable of secreting gastrin and other neuropeptides. From its inception, the postulate became the subject of controversy., Design: To extend previous observations, we examined the lymph nodes located in the gastrinoma triangle of 20 autopsy cases for the presence of neuroendocrine cells, as determined by immunohistochemistry, using antibodies to a panneuroendocrine substance (eg, synaptophysin) and a specific neuropeptide (eg, gastrin). Scanning for positive cells was performed by 2 observers (M.E.H. and M.C.C.). We compared the findings in these lymph nodes with lymph nodes obtained from axillary and inguinal dissections during surgical procedures., Results: In all, 417 lymph nodes were studied. Five of the 20 gastrinoma triangle cases contained synaptophysin reactive cells, whereas 3 had gastrin reactive cells. None of the axillary and inguinal lymph nodes contained neuroendocrine cells., Conclusion: Our findings support the hypothesis of entrapment of neuroendocrine cells during development and the presence of primary nodal gastrinomas.