Coin is the most common foreign body swallowed by pediatric age group. The multiple coin swallowing is extremely rare and very few cases had been reported in English literature. Most of them were present at different site and had different alignment in the esophagus. The location of the coin (trachea vs. esophagus) is commonly determined by the alignment of the coin on radiographic studies. A 4-year-girl was presented to us with history of coin ingestions one day back without any respiratory distress. On radiological study there was suspicion of two coins on same location and alignment. The diagnosis was confirmed after removal. The both coin was removed successfully by esophagoscopy. Unexpected second foreign bodies in pediatric esophageal coin ingestions are rare and it is mandatory to do post operative radiography after removal to exclude duplex coin or tracheal coin. We are presenting this case because of its rarity, difficulty in diagnosis especially when proper history is not available.
The Conditional by Inversion (COIN) method for engineering conditional alleles relies on an invertible optimized gene trap-like element, the COIN module, for imparting conditionality. The COIN module contains an optimized 3′ splice site-polyadenylation signal pair, but is inserted antisense to the target gene and therefore does not alter transcription, until it is inverted by Cre recombinase. In order to make COIN applicable to all protein-coding genes, the COIN module has been engineered within an artificial intron, enabling insertion into an exon.
Therefore, theoretically, the COIN method should be applicable to single exon genes, and to test this idea we engineered a COIN allele of Sox2. This single exon gene presents additional design challenges, in that its proximal promoter and coding region are entirely contained within a CpG island, and are also spanned by an overlapping transcript, Sox2Ot, which contains mmu-miR1897. Here, we show that despite disruption of the CpG island by the COIN module intron, the COIN allele of Sox2 (Sox2COIN) is phenotypically wild type, and also does not interfere with expression of Sox2Ot and miR1897. Furthermore, the inverted COIN allele of Sox2, Sox2INV is functionally null, as homozygotes recapitulate the phenotype of Sox2ßgeo/ßgeo mice, a well-characterized Sox2 null. Lastly, the benefit of the eGFP marker embedded in the COIN allele is demonstrated as it mirrors the expression pattern of Sox2.
Our results demonstrate the applicability of the COIN technology as a method of choice for targeting single exon genes.
Between 1982 and 1985 removal of a nonorganic, smooth, radiopaque foreign body in the esophagus with a Foley balloon catheter under fluoroscopic control without sedation was attempted in 38 children. An ultra-low-dose fluoroscopic unit was used. In 35 children the foreign body (a coin) was either easily removed (in 29 cases) or advanced into the stomach (in 6). No complications of the procedure were observed. In three children the foreign body could not be removed by this means; it was subsequently removed by endoscopy (in two cases, both of coins) or esophagotomy (in two cases, both of coins) or esophagotomy (in one, of a stone). When carefully performed, removal of blunt, recently ingested esophageal foreign bodies with a Foley catheter under fluoroscopic control is a safe mode of treatment.
Foreign body ingestion is a common emergency situation in children with one or a few objects having been ingested. Here we report our experience using endoscopic retrieval in a female centenarian with dyspnea and foreign bodies in the esophagus. She attempted suicide by swallowing 26 coins and two other foreign bodies. A gastroscope was used to remove all foreign bodies in the lower esophagus. In total, 26 coins, one ferrous ring and one cylindrical plastic object were retrieved. To our knowledge, this is the first clinical report on retrieval of so many foreign bodies in a single case.
Foreign body; Esophagus; Endoscopy; Coin; Gastroscope; Retrieval basket
Nanoparticle technologies are significantly impacting the development of both therapeutic and diagnostic agents. At the intersection between treatment and diagnosis, interest has grown in combining both paradigms into clinically effective formulations. This concept, recently coined as theranostics, is highly relevant to agents that target molecular biomarkers of disease and is expected to contribute to personalized medicine. Here we review state-of-the-art nanoparticles from a therapeutic and a diagnostic perspective and discuss challenges in bringing these fields together. Major classes of nanoparticles include, drug conjugates and complexes, dendrimers, vesicles, micelles, core–shell particles, microbubbles, and carbon nanotubes. Most of these formulations have been described as carriers of either drugs or contrast agents. To observe these formulations and their interactions with disease, a variety of contrast agents have been used, including optically active small molecules, metals and metal oxides, ultrasonic contrast agents, and radionuclides. The opportunity to rapidly assess and adjust treatment to the needs of the individual offers potential advantages that will spur the development of theranostic agents.
Molecular imaging; Theranostic; Cancer; Chemotherapy; Drug conjugates; Drug complexes; Dendrimers; Vesicles; Micelles; Core–shell; Microbubbles; Carbon nanotubes
Ciliopathies are a group of clinically and genetically overlapping disorders whose etiologies lie in defective cilia. These are antenna-like organelles on the apical surface of numerous cell types in a variety of tissues and organs, the kidney included. Cilia play essential roles during development and tissue homeostasis, and their dysfunction in the kidney has been associated with renal cyst formation and renal failure. Recently, the term “renal ciliopathies” was coined for those human genetic disorders that are characterized by nephronophthisis, cystic kidneys or renal cystic dysplasia. This review focuses on renal ciliopathies from a human genetics perspective. We survey the newest insights with respect to gene identification and genotype–phenotype correlations, and we reflect on candidate ciliopathies. The opportunities and challenges of next-generation sequencing (NGS) for genetic renal research and clinical DNA diagnostics are also reviewed, and we discuss the contribution of NGS to the development of personalized therapy for patients with renal ciliopathies.
Cilia; Renal ciliopathies; Renal cysts; Genotype–phenotype correlations; Next-generation sequencing; Personalized medicine
Anaphylaxis is a source of anxiety for patients and healthcare providers. It is
a medical emergency that presents with a broad array of symptoms and signs,
many of which can be deceptively similar to other diseases such as myocardial
infarction, asthma, or panic attacks. In addition to these diagnostic challenges,
anaphylaxis presents management difficulties due to rapid onset and
progression, lack of appropriate self-treatment education and implementation by
patients, severity of the allergic response, exacerbating medications or concurrent
disease, and unpredictability. The most common causes of anaphylaxis are food
allergies, stinging insects and immunotherapy (allergy shots) but idiopathic
anaphylaxis, latex allergy and drug hypersensitive all contribute to the
epidemiology. Reactions to IVP and other dyes are coined anaphylactoid reactions
but have identical pathophysiology and treatment, once the mast cell has been
degranulated. As many antigens can be the trigger for fatal anaphylaxis, it is useful
to examine the features of each etiology individually, highlighting factors common
to all fatal anaphylaxis and some specific to certain etiologies. Generally what
distinguishes a fatal from non fatal reaction is often just the rapidity to apply correct
therapy. Prevention is clearly the key and should identify high-risk patients in
an attempt to minimize the likely of
a severe reaction. Although fatal anaphylaxis is rare, it is likely underreported.
Aluminum phosphide is a systemic lethal poison. Fistulous communication between esophagus and airway tract (esophagorespiratory fistula) has rarely been reported in the survivors of aluminum phosphide poisoning. We report a case of benign esophagobronchial fistula secondary to aluminum phosphide poisoning, which to best of our knowledge has not been reported in the medical literature.
Aluminum phosphide; esophagobronchial fistula; poisoning
Barrett esophageal cancer has the fastest growing incidence of any cancer in Western countries. In Asian countries, most cases of esophageal cancer consist of squamous cell carcinomas, not adenocarcinomas. Recently, however, the increase in the number of Barrett esophagus cases with subsequent Barrett cancer has become worrisome in Asian countries, as the number of patients with gastro-esophageal reflux disease has been increasing in these countries. In this review, recent reports regarding Barrett esophagus in Asian countries have been collected and this problem is discussed from various perspectives. In Asia, long-segment Barrett esophagus is much less prevalent than in Western countries, whereas short-segment Barrett esophagus is frequently found. In epidemiologic studies, evaluation of the prevalence of Barrett esophagus is limited by poor interob-server diagnostic agreement. Standard criteria for the endoscopic diagnosis of Barrett esophagus in Asian patients, especially of the short-segment type, should be established as soon as possible. A high prevalence of hiatal hernia and a decreasing prevalence of Helico-bacter pylori infection may increase the number of Barrett esophagus cases and subsequent Barrett cancer in Asian countries in the near future. Therefore, a strategy for the clinical management of Barrett esophagus in Asian countries should be devised.
Barrett esophagus; Asian population; endoscopic diagnosis; Helicobacter pylori infection
Foreign bodies in the aerodigestive tract continue to be a common problem that contributes significantly to high morbidity and mortality worldwide. This study was conducted to describe our own experience with endoscopic procedures for removal of foreign bodies in the aerodigestive tract, in our local setting and compare with what is described in literature.
This was a prospective descriptive study which was conducted at Bugando Medical Centre between January 2008 and December 2009. Data were collected using a structured questionnaire and analyzed using SPSS computer software version 15.
A total of 98 patients were studied. Males outnumbered females by a ratio of 1.1:1. Patients aged 2 years and below were the majority (75.9%). The commonest type of foreign bodies in airways was groundnuts (72.7%) and in esophagus was coins (72.7%). The trachea (52.2%) was the most common site of foreign body's lodgment in the airways, whereas cricopharyngeal sphincter (68.5%) was the commonest site in the esophagus. Rigid endoscopy with forceps removal under general anesthesia was the main treatment modality performed in 87.8% of patients. The foreign bodies were successfully removed without complications in 90.8% of cases. Complication rate was 7.1% and bronchopneumonia was the most common complication accounting for 42.8% of cases. The mean duration of hospital stay was 3.4 days and mortality rate was 4.1%.
Aerodigestive tract foreign bodies continue to be a significant cause of childhood morbidity and mortality in our setting. Rigid endoscopic procedures under general anesthesia are the main treatment modalities performed. Prevention is highly recommended whereby parents should be educated to keep a close eye on their children and keep objects which can be foreign bodies away from children's reach.
The term synovioma was coined by Smith in 1927, and later in 1936 Knox suggested the name synovial sarcoma. It occurs primarily in the paraarticular regions, usually in close association with tendon sheaths, bursae, and joint capsules. On rare occasions it may be seen in areas without any apparent relationship to synovial structures as in parapharyngeal region or the abdominal cavity. The first description of synovial sarcoma in the head and neck region was by Pack and Ariel in 1950. The majority of these tumors seem to take origin from paravertebral connective tissue spaces and manifest as solitary retropharyngeal or parapharyngeal masses near the carotid bifurcation. Synovial sarcoma has been reported in soft palate, tongue, maxillofacial region, angle of mandible, sternoclavicular region, scapular region, and the esophagus. We report a case of 28-year-old male patient with synovial sarcoma in mandibular region with biphasic pattern.
Biphasic pattern; head and neck; synovial sarcoma
Foreign body in the esophagus is not an unusual finding. Coin in children and bone fragments in adults are commonly observed foreign bodies. Usually foreign bodies are removed within few hours to few days. Forgotten or unattended foreign bodies are seen in either mentally retarded patients or in children. We are reporting here a case, having unusual foreign body in oesophagus, i.e. a thorn of babul tree since one month, presented as perioeso-phagitis with dysphagea in a mentally retarded child of 12 years.
Foreign body; oesophagus
Functional dyspepsia is a common disorder which imposes significant diagnostic and treatment challenges for patients and physicians. The most recent update of the diagnostic criteria subdivides functional dyspepsia into two subcategories based on the main symptom of epigastric pain or postmeal fullness. As we discuss in this review, several studies have shown significant overlap in symptoms and pathophysiology between functional dyspepsia, irritable bowel syndrome, and the spectrum of reflux disorders. This overlap in symptoms can be informative in helping us to understand the underlying pathophysiology, diagnostic approaches, and treatment strategies. The addition of diagnostic testing such as pH impedance manometry of the distal esophagus to the current common diagnostic tests might be helpful in distinguishing between functional dyspepsia and reflux disease. Importantly, various treatment modalities may be more effective than others if the main symptom is burning rather than pain or postmeal fullness rather than early satiation.
Leiomyomas of esophagus, although rare, are the most frequent benign tumors of esophagus. Aim of this study is the presentation of 7 patients with esophageal leiomyomas who underwent surgical treatment during a 9-year period.
Epidemiological data (sex, age), the presenting symptoms, diagnostic examinations, tumor location, histopathological findings and the safety and efficacy of surgical resection are analyzed and assessed.
5 men and 2 women with mean age of 56.9 years were operated. In 3 cases the tumor was located at the lower esophagus, while in the other 4 cases, the leiomyoma was found at the median third of esophagus. 4 patients had severe symptoms related to the leiomyoma, such as dysphagia and epigastric pain. All patients underwent a right postolateral thoracotomy with enucleation of the lesion. None of them received resection of part of the esophagus. The mean diameter of the resected tumors was 4.3 cm. The dimensions of leiomyomas were immediately associated with the symptoms. In no case was detected malignancy or recurrence. All patients were relieved from their symptoms, while postoperative morbidity and mortality did not occur.
Esophageal leiomyoma is a benign tumor, which causes symptoms only if its size becomes large. Surgical enucleation is considered to be safe and effective, without complications.
Background and study aim
The establishment of precise and valid diagnostic criteria is the first step towards understanding the pathogenesis of Barrett’s esophagus in Asia. The present study determined the interobserver reliability in the endoscopic diagnosis and grading of Barrett’s esophagus among Asian endoscopists.
Patients and methods
Video clips of endoscopy in 21 patients with and without Barrett’s esophagus were used for training (n=3) and standardized diagnosis and grading (n=18) of Barrett’s esophagus by endoscopists from seven hospitals in different Asian regions/countries. Barrett’s esophagus, where present, was graded using the Prague C & M Criteria whereby the circumferential extent of Barrett’s segment (C value), maximum extent of Barrett’s segment (M value), location of the gastroesophageal junction, and location of the diaphragmatic hiatus were scored. The intraclass correlation coefficients (ICC) were calculated as a measure of interobserver reliability.
A total of 34 endoscopists participated. The ICC values for the scores of C value, M value, location of the gastroesophageal junction, and location of the diaphragmatic hiatus were 0.92 (95% CI, 0.88–0.97), 0.94 (0.90–0.98), 0.86 (0.78–0.94), and 0.81 (0.71–0.92), respectively, indicating excellent interobserver reliability. The differences in region/country, experience of endoscopists, volume of participating center, or the primary practice type did not have significant effect on the reliability. The ICC values for recognition of Barrett’s esophagus with an extent ≥1 cm were 0.90 (0.80–1.00) and 0.92 (0.87–0.98) for the C and M values, respectively, whereas the corresponding ICC values for Barrett’s segment <1 cm were 0.18 (0.03–0.32) and 0.21 (0.00–0.51), respectively.
Despite the relatively uncommon occurrence of Barrett’s esophagus in Asia, endoscopists in our study exhibited excellent consistency in the endoscopic diagnosis and grading of Barrett’s esophagus using the Prague C & M Criteria. In view of the low interobserver reliability in recognizing Barrett’s esophagus segments of <1 cm, future studies in Asia should take this into account in their selection strategies as to recruit as homogeneous a population for study as possible.
In 1997, highly pathogenic avian influenza (HPAI) viruses caused outbreaks of disease in domestic poultry markets in Hong Kong. The virus has also been detected in infected poultry in Europe and Africa.
The objective of this study was to determine the efficacy of a heterologous vaccine administered with and without the aluminum hydroxide adjuvant in ferrets challenged with HPAI (A/Vietnam/1203/04).
Animals in four of the five groups were vaccinated twice 21 days apart, with two doses of a heterologous monovalent subvirion vaccine with or without an aluminum hydroxide adjuvant and challenged with a lethal target dose of A/Vietnam/1203/04.
All animals vaccinated with the heterologous vaccine in combination with the aluminum hydroxide adjuvant survived a lethal challenge of A/Vietnam/1203/04. Four of the eight animals vaccinated with 30 µg of the vaccine without the adjuvant survived, while two of the eight animals vaccinated with 15 µg of the vaccine without the adjuvant survived. None of the unvaccinated control animals survived challenge. Additionally, changes in virus recovered from nasal washes and post-mortem tissues and serology suggest vaccine efficacy.
Altogether, the data suggest that the heterologous vaccine in combination with the aluminum hydroxide adjuvant offers maximum protection against challenge with A/Vietnam/1203/04 when compared to the unvaccinated control animals or animals vaccinated without any adjuvant.
Highly Pathogenic Avian Influenza; H5N1; heterologous vaccine
The detection of high grade dysplasia and cancer in Barrett’s esophagus (BE) can be challenging. Confocal laser endomicroscopy (CLE) allows in vivo visualization of mucosal histology during endoscopy.
To determine if CLE with optical biopsy and targeted mucosal biopsy (CLE-TB) improves the diagnostic yield of endoscopically inapparent BE-associated neoplasia compared to standard endoscopy with a 4-quadrant random biopsy (SE-RB) protocol
Prospective, double-blind, randomized crossover study
Single tertiary care academic center
Patients with BE undergoing routine surveillance or non-localized endoscopically inapparent BE-associated neoplasia referred for treatment
All participants underwent both a confocal endomicroscopy with targeted biopsy procedure and standard endoscopy with 4-quadrant biopsy procedure in a randomized order.
Main outcome measurements
Increase in diagnostic yield for neoplasia, reduction in mucosal biopsy number, final pathologic diagnosis.
CLE with targeted biopsy almost doubled the diagnostic yield for neoplasia and was equivalent to the standard protocol for the final diagnosis of neoplasia. 2/3 of patients in the surveillance group did not need any mucosal biopsies at all.
Single center study
CLE with targeted biopsy significantly improves the diagnostic yield for endoscopically inapparent BE neoplasia compared to a standard endoscopy with random biopsy protocol. CLE with targeted biopsy also greatly reduces the number of biopsies needed per patient and allows some patients without neoplasia to completely forgo mucosal biopsy.
confocal endomicroscopy; Barrett’s esophagus
Objectives: This study investigated whether coins of the new European currency (€) corrode when they are exposed to gastric acid, and whether this change can be detected radiographically.
Methods: The eight different denominations of € coins were immersed for seven days in 0.15 N hydrochloride acid (HCl), which corresponds to the level of post-prandial gastric acid. A Swedish crown coin and three different Austrian schilling coins were used as controls. The coins were weighed and radiographed daily to evaluate visible corrosions and HCl was analysed daily for possible dissolved substances.
Results: All coins lost weight within 24 hours after exposure to HCl. The 1, 2, and 5 € cent coins developed changes that were visible on radiographs. The weights of all coins decreased by 0.43% to 11.30% during one week. The dissolved substances measured in the HCl corresponded to the different metals and alloys of the coins, except for copper, which does not dissolve in HCl. The highest absolute weight loss was observed in the Swedish crown coin (0.67 g), and the highest relative weight loss in the 1 Austrian schilling coin (11.30%). The two € coins that showed the highest absolute and relative weight losses were the 2 € (0.54 g or 6.35%) and the 1 € (0.48 g or 6.39%) coin.
Conclusions: A higher rate of toxicity for the new European coins compared with coins of other currencies is not expected, unless a massive coin ingestion occurs.
Purpose of review
Our article discusses the current understanding of screening and surveillance options for Barrett’s esophagus and emerging concepts that have the potential to improve the effectiveness and cost-effectiveness of surveillance.
Although endoscopic surveillance of patients with Barrett’s esophagus is commonly practiced in order to detect high-grade dysplasia and early esophageal adenocarcinoma (EAC), the reported incidence of EAC in Barrett’s esophagus patients varies widely. Recent studies found the risk of progression from Barrett’s esophagus to EAC to be significantly lower than previously reported, raising concerns regarding the limitations of current surveillance strategies. Advances in imaging techniques and their enhanced diagnostic accuracy may improve the value of endoscopic surveillance. Additionally, various efforts are ongoing to identify biomarkers that identify individuals at higher risk of cancer, possibly allowing for individual risk stratification.
These new data highlight some of the opportunities to revise and improve surveillance in patients with Barrett’s esophagus. The incorporation of new advances such as imaging techniques and biomarkers has the potential to improve the effectiveness and cost-effectiveness of new surveillance regimens.
Barrett’s esophagus; cost-effectiveness; esophageal adenocarcinoma; surveillance
Gastrointestinal melanosis is observed most frequently in the colon it also can develop in the ileum, duodenum and esophagus very rarely. Melanosis ilei was thought that causative materials such as aluminum, magnesium, silicate, titanium and other compounds entered the body through the ingestion of agents. We experienced a case of melanosis in the terminal ileum that a 65-year-old female patient ingested 10 g edible charcoal everyday for 3 years to address symptoms of chronic abdominal pain. In Korea, edible charcoal has been considered to be an effective folk remedy for patients with diarrhea or chronic abdominal pain. In our case, a follow up colonoscopy was performed 3.5 years after the termination of the ingestion of edible charcoal, at which point pigmentation was faded color intensity. In conclusion, it is thought that melanosis ilei is a rare disease by ingestion of causative materials and is discontinuous, local and reversible disease.
Melanosis; Ileum; Charcoal; Capsule endoscopy; Electron microscopy
Hemangiomas that arise in cervical esophagus are extremely rare, representing 3.3% of all benign esophageal tumors. Although endoscopic mucosal resection (EMR) and potassium titanyl phosphate/yttrium aluminum garnet (KTP/YAG) laser therapy have been used with success for small tumors, the safety and efficacy in the case of large tumors remains uncertain. We report the successful resection of cervical esophageal hemangioma through a cervical esophagotomy in a patient with thyroid cancer who needed a cervical collar incision.
Esophageal neoplasms; Hemangioma; Thyroid neoplasm
Comprehensive microscopy of distal esophagus could greatly improve the screening and surveillance of esophageal diseases such as Barrett’s esophagus by providing histomorphologic information over the entire region at risk. Spectrally encoded confocal microscopy (SECM) is a high-speed reflectance confocal microscopy technology that can be configured to image the entire distal esophagus by helically scanning the beam using optics within a balloon-centering probe. It is challenging to image the human esophagus in vivo with balloon-based SECM, however, because patient motion and anatomic tissue surface irregularities decenter the optics, making it difficult to keep the focus at a predetermined location within the tissue as the beam is scanned. In this paper, we present a SECM probe equipped with an adaptive focusing mechanism that can compensate for tissue surface irregularity and dynamic focal variation. A tilted arrangement of the objective lens is employed in the SECM probe to provide feedback signals to an adaptive focusing mechanism. The tilted configuration also allows the probe to obtain reflectance confocal data from multiple depth levels, enabling the acquisition of three-dimensional volumetric data during a single scan of the probe. A tissue phantom with a surface area of 12.6 cm2 was imaged using the new SECM probe, and 8 large-area reflectance confocal microscopy images were acquired over the depth range of 56 μm in 20 minutes. Large-area SECM images of excised swine small intestine tissue were also acquired, enabling the visualization of villous architecture, epithelium, and lamina propria. The adaptive focusing mechanism was demonstrated to enable acquisition of in-focus images even when the probe was not centered and the tissue surface was irregular.
(170.1790) Confocal microscopy; (170.2150) Endoscopic imaging; (170.2680) Gastrointestinal
For radiotherapy planning, contouring of target volume and healthy structures at risk in CT volumes is essential. To automate this process, one of the available segmentation techniques can be used for many thoracic organs except the esophagus, which is very hard to segment due to low contrast. In this work we propose to initialize our previously introduced model based 3D level set esophagus segmentation method with a principal curve tracing (PCT) algorithm, which we adapted to solve the esophagus centerline detection problem. To address challenges due to low intensity contrast, we enhanced the PCT algorithm by learning spatial and intensity priors from a small set of annotated CT volumes. To locate the esophageal wall, the model based 3D level set algorithm including a shape model that represents the variance of esophagus wall around the estimated centerline is utilized. Our results show improvement in esophagus segmentation when initialized by PCT compared to our previous work, where an ad hoc centerline initialization was performed. Unlike previous approaches, this work does not need a very large set of annotated training images and has similar performance.
Curve Tracing; Level Sets; CT; 3D Image Segmentation; Spatial; Shape Model; Radiation Oncology
A procedure to teach four mild and moderately retarded persons to sum the value of coin combinations was tested. Subjects were first taught to count a single target coin, and then to sum that coin in combination with coins previously trained. Five American coins and various combinations were trained. Modelling, modelling with subject participation, and independent counting by the subject constituted the training sequence. The subjects improved from a mean pretest score of 29% to 92% correct at posttest. A four-week followup score showed a mean of 79% correct. A multiple-baseline design suggested that improvement in coin-counting performance occurred only after the coin was trained. The results indicate that this procedure has potential for teaching the retarded to sum combinations of coinds in 5 to 6 hr of instruction.
A program was designed to teach coin equivalence to mentally retarded adolescents. Coin equivalence was defined as choosing several different combinations of coins to equal specified target values. A pretest-posttest matched-groups design was employed with an experimental group receiving the monetary training, and a no-training control group. A multiple baseline across coin-counting responses was also incorporated in the experimental group. Training was divided into six stages, each teaching one specific method of combining coins to equal 10 target values from 5 cents through 50 cents. A three-component response chain was used, requiring (a) naming, (b) selecting and counting, and (c) depositing target monetary values into a coin machine. Experimental subjects improved significantly in coin equivalence performance and maintained their skill on follow up tests; control subjects did not.