Endoluminal ultrasound in gastroenterology: application of new technology.
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Animals↗
Biomedical subjects
L S Miller
Publications and source records attributed to L S Miller.
Less frequent causes of lower gastrointestinal bleeding.
In the United States, four diseases account for the vast majority of cases of lower intestinal bleeding: arteriovenous malformation, diverticulosis, neoplasms, and internal hemorrhoids. In this article the authors discuss less frequent causes of gastrointestinal bleeding. "Common" less frequent causes of gastrointestinal bleeding include solitary rectal ulcer syndrome, colonic varices, mesenteric vascular insufficiency, small bowel diverticula, Meckel's diverticulum, aortoenteric fistula, vasculitis, small intestinal ulceration, endometriosis, radiation-induced injury, and intussusception. Less frequent causes of gastrointestinal bleeding that have been recently described include portal colopathy, diversion colitis, and gastrointestinal bleeding in runners.
Colon↗
Endoluminal ultrasonography of the distal esophagus in systemic sclerosis.
BACKGROUND: The aim of this study is to apply high-resolution endoluminal sonography (HRES) to the study of the esophageal disease in systemic sclerosis (SSc). METHODS: An HRES transducer was used to image the esophagus. Autopsy specimens of normal and SSc esophagi were imaged to define a hyperechoic abnormality in the normally hypoechoic muscularis propria. The presence or absence of this hyperechoic abnormality of the esophagus in SSc patients was compared with sonographic findings in normal volunteers. The degree of the hyperechoic abnormality was correlated with the results of functional esophageal studies including esophageal motility, lower esophageal sphincter pressure, and 24-hour pH monitoring in SSc patients. RESULTS: A hyperechoic abnormality in the normally hypoechoic muscularis propria on HRES seemed to correspond with the presence of fibrosis on histological sections from the distal esophagus in SSc autopsy specimens. A significant difference was found in the presence of this hyperechoic abnormality in patients with SSc when compared with normal controls (P < 0.001). Finally, there were strong positive correlations between the degree of this hyperechoic abnormality and esophageal manometric abnormalities (r = 0.89; P < 0.001) and supine (r = 0.74; P < 0.01) and total (r = 0.70; P < 0.02) acid reflux on 24-hour pH monitoring. CONCLUSIONS: HRES is a sensitive new method to determine the presence or absence of hyperechoic abnormalities in the muscularis propria and to predict functional abnormalities of the esophagus in patients with SSc.
Adult↗
Gastric and esophageal varices: 20-MHz transnasal endoluminal US.
To image esophageal and gastric varices qualitatively and to measure esophageal varices quantitatively, 29 patients with portal hypertension underwent transnasal esophageal and gastric ultrasonography (US). Twenty-three patients underwent standard endoscopy. Endoluminal US demonstrated the varices as anechoic areas with communications in the submucosal, periesophageal, and perigastric regions, as well as ascites visualized through the gastric wall. Interobserver variation between two investigators for measurements of the largest esophageal varix in each patient was r value of .99 for diameter, r value of .99 for cross-sectional surface area, and r value of .98 for circumference. Endoscopy for evaluation of gastric varices had a sensitivity of 48% and a specificity of 50% and for evaluation of esophageal varices had a sensitivity of 94% and a specificity of 17%. Periesophageal and perigastric varices could not be visualized at endoscopy. Transnasal esophageal US, a new imaging technique with which to detect and measure esophageal varices, is a more sensitive modality than endoscopy for the detection of gastric varices.
Adolescent↗
Sonographically guided laparoscopy and mediastinoscopy using miniature catheter-based transducers.
Miniature ultrasound transducers (12.5 MHz) housed in 9 Fr catheters were passed through a laparoscope or mediastinoscope to image a variety of normal and abnormal structures within the peritoneal cavity and mediastinum in 20 patients. These transducers made it possible to visualize the gallbladder and bile ducts and evaluate for the presence of stones, to detect masses and provide guidance for their aspiration or biopsy, and to image the internal structures of the ovary and fallopian tube. In addition, these miniature transducers were used to locate such normal vital structures as blood vessels, thereby allowing the surgeon to decide on the best approach for dissection during mediastinoscopy. During conventional surgery, the surgeon or gynecologist can palpate an area of abnormality not directly visualized. However, during laparoscopy and mediastinoscopy direct palpation is not possible. Therefore, it is important to find another method to determine what structures lie beneath the visualized surface. These miniature ultrasound transducers appear to offer a means for making such determinations.
Adult↗
High-frequency endoluminal ultrasonography of the esophagus in human autopsy specimens.
A 20 MHz ultrasound transducer housed in a 6.2 Fr catheter was used to image human esophageal autopsy specimens from six cadavers. Histologic sections taken from the areas imaged were correlated with cross-sectional sonographic images. Six echo layers were seen in the non-fluid-filled esophagus whereas seven echo layers were seen in the fluid-filled esophagus. These seven layers correspond to the following histologic structures: first hyperechoic layer--mucosa (including squamous epithelium and lamina propria); second thin hypoechoic layer--muscularis mucosae; third very bright hyperechoic layer--submucosa; fourth hypoechoic layer--circular smooth muscle; fifth thin hyperechoic layer--intermuscular connective tissue; sixth hypoechoic layer--longitudinal smooth muscle; seventh hyperechoic layer--adventitia.
Adult↗
The pharmacist as an active member of the institutional review board.
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Clinical Protocols↗
The economic burden of affective disorders.
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Adolescent↗
Therapeutic efficacy of a high-affinity anticarcinoembryonic antigen monoclonal antibody (COL-1).
COL-1 is a murine IgG2a monoclonal antibody (MAb) with a high affinity (1.4 x 10(9) M-1) for carcinoembryonic antigen (CEA) and no detectable reactivity for CEA-related antigens, such as nonspecific cross-reacting antigen (NCA) and normal fecal antigen (NFA). 125I-labeled COL-1 IgG was shown to efficiently and specifically target the LS-174T human colon carcinoma xenograft in athymic mice. Dose titration studies in this same model with 131I-labeled COL-1 demonstrated reduction of tumor growth rate when 300 microCi of the immunoconjugate was used (0.005 > p > 0.001). Administration of higher levels as a single dose led to increased toxicity. Dose fractionation experiments with 131I-COL-1 demonstrated the ability to administer much higher levels of the immunoconjugate with little or no toxicity, which resulted in a greater therapeutic efficacy. For example, three fractions of 200 microCi of 131I-COL-1 given at weekly intervals (for a total of 600 microCi) resulted in the substantial reduction (p < 0.0005) of the growth of established tumors in 100% (7/7) of mice, and in no evidence of tumor growth in 71% (5/7) of mice, at the end of the 63-day observation period. These results thus demonstrate the potential therapeutic efficacy for radiolabeled COL-1 in clinical trials and demonstrate the principle of the advantage of dose fractionation protocols for this immunoconjugate.
Adenocarcinoma, Mucinous↗
Career ladder for pharmacy interns.
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Career Mobility↗
Therapeutic advantage of high-affinity anticarcinoma radioimmunoconjugates.
The effect of the relative affinity (Ka) on the antitumor efficacy of monoclonal antibodies (MAbs) has been questioned. It has previously been shown in experimental models that the use of MAbs with higher relative Kas manifests itself in a higher percentage of injected dose of MAb bound to tumor. On the other hand, mathematical models have proposed that the use of higher affinity MAbs may be disadvantageous for antitumor effects, since higher Ka MAbs would bind more antigen and prevent penetration of MAb through tumor. To test this hypothesis, three MAbs reacting to the human pancarcinoma antigen TAG-72 were used as radioimmunoconjugates for therapeutic efficacy versus the LS-174T human colon carcinoma xenograft. MAbs B72.3, CC49, and CC83 have all been shown by depletion studies to react to the same molecule and to all react with overlapping epitopes. While the relative Ka of B72.3 is 2.5 x 10(9) M-1, the relative Kas of CC49 and CC83 are 16.2 and 27.7 x 10(9) M-1, respectively. Each MAb was radiolabeled with 131I, and each radioimmunoconjugate was assayed at five dose levels for therapeutic efficacy using the human xenograft model. The results of these studies demonstrate substantial therapeutic advantage of the higher affinity MAbs CC49 and CC83 versus B72.3 at every dose level. While 500 microCi of B72.3 were required to reduce tumor growth in only a minority of tumor-bearing animals, the use of the same amount or less of the radioimmunoconjugates of CC49 or CC83 resulted in strong antitumor effects in 80 to 100% of tumor-bearing animals. Thus, stronger antitumor effects were seen using as little as 2.5- to 3-fold less of the higher Ka immunoconjugates CC49 and CC83 as compared with B72.3. While we acknowledge the potential disadvantages of higher Ka MAbs in some situations, at least the experimental studies and model system described here show that a distinct therapeutic advantage exists with the use of higher affinity immunoconjugates.
Adenocarcinoma, Mucinous↗
Help-seeking behavior and attitude of Chinese Americans regarding psychological problems.
Investigated the help-seeking behavior and attitude regarding psychological problems as mediated by mental health status, acculturation level, and sociodemographic characteristics in a community sample of Chinese Americans. Of the 128 respondents, 17 (13.3%) had consulted professional help for a nervous or emotional problem. Compared to the others, they reported significantly poorer mental health status (i.e., had more physical symptoms, had once come close to experiencing a "nervous breakdown," and had a relative who had been in treatment), and were more likely to be American-born. For those who had not previously sought help, attitude toward help seeking was examined. A positive attitude was mediated by superior English ability, being younger, married, and from a lower SES background. The findings suggested help-seeking behavior is primarily mediated by presence of need, whereas attitude reflected a general propensity. Acculturation was an important predictor of both behavior and attitude, with the less acculturated most in need of education about the utility of mental health service.
Acculturation↗
Acetylator genotype-dependent N-acetylation of arylamines in vivo and in vitro by hepatic and extrahepatic organ cytosols of Syrian hamsters congenic at the polymorphic acetyltransferase locus.
Our laboratory recently reported the successful construction of homozygous rapid (Bio. 82.73/H-Patr) and homozygous slow (Bio. 82.73/H-Pat(s)) acetylator congenic Syrian hamsters. These hamsters are isogenic except for the polymorphic acetylator gene locus (Pat) and perhaps other closely linked loci. The purpose of the present investigation was to assess the expression of acetylator genotype both in vivo and in vitro in a variety of hepatic and extrahepatic organ cytosols. Levels of arylamine N-acetyl-transferase were generally high and in the relative order: liver greater than colon greater than kidney greater than pancreas greater than prostate, urinary bladder, and lung. However, an acetylator gene dose-response was clearly expressed in each tissue, with highest levels in homozygous Patr acetylators, intermediate levels in heterozygous Patr/Pat(s) acetylators, and lowest levels in homozygous Pat(s) acetylators. The magnitude of the acetylator genotype-dependent differences in N-acetyltransferase activity were substrate specific, wherein p-aminobenzoic acid showed the largest differences and p-aminophenol the smallest. The N-acetylation of p-aminobenzoic acid in vivo also reflected acetylator genotype in the congenic hamsters. These results further document the successful construction of rapid and slow acetylator congenic hamsters which should prove very valuable in future studies to assess the role of acetylator genotype in the toxicity and carcinogenicity of arylamine chemicals.
Acetylation↗
The endoscopic Doppler and ulcer rebleeding risk: probing the source.
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Endoscopy, Digestive System↗
Acute esophageal hemorrhage from a vagal neurilemoma.
A man with known systemic neurofibromatosis developed an acute upper gastrointestinal hemorrhage while hospitalized after a neurosurgical procedure. Endoscopic evaluation showed a vascular lesion with an appearance consistent with a Dieulafoy-type lesion in the distal esophagus. Despite multiple endoscopic procedures with attempted coagulation of the bleeding lesion, the patient continued to have life-threatening hemorrhaging. At thoractomy, a tumor was found to arise from the vagus nerve at the site of bleeding. This tumor was resected and histologically determined to be a neurilemoma. Acute bleeding into the esophagus associated with this type of tumor has not been previously reported.
Cranial Nerve Neoplasms↗
Time of day effects on a human force discrimination task.
Although numerous studies have demonstrated reliable relationships between various human performance measures and time of day, disagreement exists concerning the shape of these relationships and their dependence on task variables. Most perceptual-motor tasks emphasize responsiveness to exteroceptive stimuli. We used a multiple force-band discrimination task that requires responsiveness to both exteroceptive and proprioceptive information. Results for a response duration measure showed a quadratic time of day trend similar to previously reported performance tasks. Response latency to the force emission cue and number of correct inband force emissions showed cubic time of day trends not typically reported in the time of day and performance literature. These results have implications for time-of-day effects on real world perceptual performance.
Body Temperature↗
Transnasal US of the esophagus: preliminary morphologic and function studies.
High-frequency catheter-based ultrasound (US) transducers can be inserted into the esophagus transnasally to evaluate esophageal wall structures. Studies were performed in two sheep esophagus specimens in vitro, in 17 healthy human subjects, and in 16 patients with esophageal abnormalities (eight with achalasia, four with scleroderma, three with esophageal carcinoma, and one with esophagitis). In the sheep specimens, endoluminal US delineated seven layers of the esophageal wall; these results correlated closely with histologic findings. Real-time US of the normal esophageal wall was performed during resting and swallowing. Muscles at the lower esophageal sphincter (LES) were shown to be thicker than muscles in the body of the esophagus. Thickening of the muscular layers at the LES in achalasia, dilated blood vessels within the submucosa in esophagitis, and fibrotic changes within the muscular layers in scleroderma were demonstrated. Extramural structures adjacent to the esophagus were also seen. These preliminary results suggest that transnasal esophageal US may become an important diagnostic tool in evaluation of the esophagus.
Adult↗
The economic burden of mental illness.
Mental illness imposes a substantial burden on individuals and society. Using data from national surveys and a newly developed methodology for calculating costs, the authors estimate that in 1985 the total economic costs of mental illness were $103.7 billion. Of this total, direct treatment and support costs were $42.5 billion, or 11.5 percent of total personal health care spending for all illnesses. Morbidity costs--the value of reduced or lost productivity--amounted to $47.4 billion. Mortality costs--the lost value of productivity due to premature death resulting from mental illness--were estimated to be $9.3 billion, or 5.1 percent of total productivity losses for all deaths. Other related costs, including the cost of caregiver services, amounted to $4.5 billion.
Activities of Daily Living↗