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Biomedical subjects

T Q Miller

Publications and source records attributed to T Q Miller.

33 records · Page 2Linked to original sources
PubMed1993

Imaging the hepatic lymphatics: experimental studies in swine.

Magnetic resonance (MR) imaging augmented with 3-D MR reconstruction provides an excellent display of the soft tissues and surface anatomy of the human body. The excellent anatomical detail of MR images makes this radiographic modality an ideal tool to teach anatomy to all health-care professionals. Previous studies of the lung and liver in swine revealed that the hepatic lymphatics communicated with the visceral pleural lymphatics via the so-called pulmonary ligament, which appears as a sheet of visceral pleura containing lymphatics and small blood vessels in the swine model. A review of the surgical operative reports at the UCLA School of Medicine revealed that the hepatic lymphatics are not connected or even ligated during hepatic resections and transplantations. Therefore, the authors hypothesized that the unattached lymphatics may be a cause of postoperative complications and that interruption of these important lymphatic pathways may specifically result in immediate ascites and right pleural effusions. Cannulation of the hepatic lymphatics is proposed as a method to reduce postoperative complications. The purpose of this research is to demonstrate the visual and radiographic display of the hepatic lymphatics in a swine model and to provide a means to teach anatomical-pathological correlation.

Animals↗
PubMed1993

Atypical desmoid tumor of the abdomen: a case report.

Desmoids are rare lesions that are histologically benign but locally aggressive. These lesions should be considered in patients who present with abdominal masses, particularly if there is a prior history of familial polyposis. This case report describes a patient with an abdominal desmoid that demonstrated atypical features on computed tomography and correlative magnetic resonance images.

Abdominal Neoplasms↗
PubMed1992

Prevalence of oesophagitis in asthmatics.

The exact relation between gastro-oesophageal reflux and asthma remains poorly understood. To determine whether gastro-oesophageal reflux in asthmatics results in oesophagitis, endoscopy and oesophageal biopsy were performed on 186 consecutive adult asthmatics. The presence or absence of reflux symptoms was not used as a selection criterion for asthmatics. Endoscopy was performed by two endoscopists using predefined criteria. All asthmatics had discrete wheezing and either a previous diagnosis of asthma or documented reversible airways obstruction of at least 20%. The oesophageal mucosa was graded as normal if no erosions or ulcerations were present in the tubular oesophagus; as oesophagitis if a mucosal break with exudate (erosions and/or ulcerations) was present; and as Barrett's if specialised (intestinal) columnar epithelium was present. A hiatal hernia was diagnosed if greater than or equal to 2 cm of gastric mucosa appeared above the diaphragm during endoscopy. Thirty nine per cent of the patients with asthma had oesophagitis or Barrett's oesophagus, or both. There was no difference in the oesophageal mucosal status between asthmatics who required and those who did not require bronchodilators. Fifty eight per cent of asthmatics had a hiatal hernia. It is concluded that oesophagitis is common and independent of the use of bronchodilator therapy in asthmatics.

Adult↗
PubMed1992

Fluoroscopic chest tube insertion and patient care.

Catheters and chest tubes may be placed under fluoroscopic control to reduce pleural effusions. This procedure has been adopted as a routine procedure at the UCLA School of Medicine in Los Angeles, California to improve patient care. This technique was modified for the placement of large chest tubes, which can be placed by a radiologist without multiple attempts or complications. Our experience with 2234 patients who underwent this procedure between 1977 and 1990 is described.

Catheterization↗
PubMed1991

Reasons for the trend toward null findings in research on Type A behavior.

The findings of many studies conducted before 1978 suggest that Type A behavior (TAB) contributes to the development of coronary heart disease (CHD). In contrast, many recent studies have found no association between these variables. Through meta-analysis, several reasons for null findings are identified. First, a type of range restriction bias, disease-based spectrum (DBS) bias, produced many null findings. A study is vulnerable to DBS bias when researchers select only high-risk or diseased Ss for study. Second, self-report measures of TAB were often associated with null findings. Finally, null results were found for all studies that used fatal myocardial infarction as a disease criterion. In addition to identifying the reasons for null findings, this research suggests that TAB, as assessed by the structured interview, is associated with CHD. More Type As (70%) were found in diseased populations of middle-aged men than in healthy populations of middle-aged men (46%).

Coronary Artery Disease↗
PubMed1991

The importance of hiatal hernia in reflux esophagitis compared with lower esophageal sphincter pressure or smoking.

The characteristics of gastroesophageal reflux disease have not been adequately defined. To determine the influence on the esophageal mucosa of hiatal hernia, lower esophageal sphincter pressure, acid reflux, and cigarettes and alcohol, we studied the reflux parameters, smoking habits, and alcohol consumption of 184 healthy, ambulatory outpatients who received endoscopy as the initial diagnostic procedure for workup of gastroesophageal reflux. Patients received endoscopic and histologic evaluations of the esophageal mucosa, prolonged ambulatory esophageal pH monitoring, and esophageal manometric determinations. Structural analysis was used to test the plausibility of various clinical theories concerning the most important factors contributing to the development of esophagitis. Statistical analyses revealed the following: (a) the lower esophageal sphincter pressure, acid contact time, and frequency of reflux episodes were highly associated with the presence of a hiatal hernia (p less than 0.003 for all parameters); (b) individuals with esophagitis had 16.5 times as many hiatal hernias as found in normal, healthy people; (c) cigarette smoking was not correlated with esophagitis but was significantly associated with increased lower esophageal sphincter pressure (r = 0.18; p less than 0.03); and (d) smoking was also not associated with increased acid contact time or increased frequency of reflux episodes. We conclude that (a) the presence of a hiatal hernia, not the pressure of the lower esophageal sphincter, is the most important predictor of reflux frequency, acid contact time, and esophagitis; (b) a decreased lower esophageal sphincter pressure, as suggested by structural analysis, is unlikely to be the cause of increased reflux episodes or esophagitis; and (c) if smoking and lower esophageal sphincter pressure are factors in the development of esophagitis, they damage the esophageal mucosa by mechanisms other than increased frequency of reflux episodes or increased acid contact time.

Computer Simulation↗
PubMed1989

Why is high resolution computerized tomography scanning used in evaluating the lungs?

High resolution computerized tomography scans have been used for medical and legal purposes to evaluate patients with a history of exposure to asbestos. Some investigators argue that high resolution scanning provides a better image of the lungs than routine computerized tomography. A review of the literature shows that although high resolution scanning displays the lymphatics in the lung, it offers no new useful diagnostic information. The authors conclude that no real advantage is attained with high resolution scanning of the lung and that pathology of disease can be determined decisively only by histology.

Evaluation Studies as Topic↗
PubMed1988

Disease based spectrum bias in referred samples and the relationship between type A behavior and coronary artery disease.

Using referred samples to study predictors of disease produces statistical problems that reduce the likelihood of obtaining statistically significant results even when a substantial relationship is present between a risk factor and a disease. The present paper refers to these problems as disease based spectrum (DBS) bias. DBS bias is present when subjects are directed into or excluded from the study sample according to their disease status. For example, healthy individuals are excluded from and diseased individuals are directed into referred samples. Therefore, DBS bias is present in referred samples. Examples from the literature on Type A behavior and coronary artery disease (CAD) are presented to illustrate how DBS bias reduces statistical associations. The results of the current research indicate DBS bias has reduced the association between Type A behavior and CAD in a number of studies reported in recent years. In addition, the present article discusses techniques for assessing and controlling for DBS bias.

Age Factors↗
PubMed1987

Neonatal pharyngeal perforation diagnosed by xenon 133 imaging.

A premature male infant developed bilateral pneumothorax and generalized subcutaneous emphysema following difficult intubation. Xenon 133 imaging revealed accumulation of radionuclide in those areas of subcutaneous emphysema indicating a large air leak from the upper respiratory tract. Pharyngeal injury was confirmed at endoscopy. Imaging with (133)Xe may offer a means of rapid diagnosis of airway injury.

Emphysema↗
PubMed1982

The role of the radiologist on the child abuse team.

Physicians in most jurisdictions are mandated to report all suspected cases of child abuse to the appropriate authorities. Often in a position to initially suspect child abuse, the radiologist must be aware of the roentgenographic manifestations of the various forms of child abuse. In recognition of the difficulty for an individual to maintain expertise in all aspects of child abuse, multidisciplinary teams have evolved to share responsibility in the diagnosis and treatment of child abuse as well as aid in prosecution of the perpetrator and in family therapy when applicable.

Child↗
PubMedDate not supplied

A test of alternative explanations for the stage-like progression of adolescent substance use in four national samples.

Previous research has established that there is a stage-like phenomenon of adolescent substance use such that alcohol use usually precedes marijuana use, and marijuana use usually precedes hard drug use. The current study tests three potential explanations for this stage-like phenomenon using nonstandard log-linear models. In four national surveys dating from 1974 to 1988, the results were consistent for both sexes, ages ranging from 12 through 18, and for Whites, Blacks, and Hispanics. The results suggest that adolescents are more likely to use alcohol before marijuana, and marijuana before hard drugs because these substances are more widely used and are used at early ages. An additional reason for the stage-like phenomenon is that there is also a group of adolescents who are willing to try all types of substances and a second group who are unwilling to use any substances. Implications for future longitudinal studies are discussed.

Adolescent↗
PubMedDate not supplied

A test of socioeconomic status as a predictor of initial marijuana use.

The current study examined the effects of socioeconomic status (SES) on adolescent marijuana use using data from a national longitudinal survey of subjects aged 11 to 17 (N = 1,725). Both direct and indirect measures of SES (e.g., Hollingshead's measure of SES, predicts marijuana use among adolescents. For males, our study found a nonlinear relationship between the Hollingshead measure and marijuana use that had not been identified in previous research. For females, the Hollingshead measure was nonsignificant when alcohol use and having friends who use marijuana were added to the model. This finding suggests that the effects of SES on marijuana use may be mediated by alcohol use and friends' use of marijuana. Weekly alcohol users were much more likely than nonusers to initiate marijuana use for both males (Odds ratio [OR] = 18.28, Confidence interval [CI] = 4.93-67.81) and females (OR = 11.75, CI = 3.22-42.86). Other significant variables for both sexes included having a job, having friends who use marijuana, and having used some alcohol in the past year. For males, grade point average (GPA), commitment to friends, urbanicity, time spent with friends, and peer strain were also significant predictors of initial marijuana use. For females, prior victimization and low school aspirations were significant. In sum, our findings suggest that psychosocial risk factors for marijuana use are substantially different for males than for females and that future researchers need to test for nonlinear relationships between SES and adolescent substance use.

Adolescent↗
PubMedDate not supplied

A test of the psychosocial vulnerability and health behavior models of hostility: results from an 11-year follow-up study of Mexican Americans.

Previous research has shown that interpersonal conflict and depression are cross-sectionally associated with hostility. Our objective was to determine whether hostility is longitudinally predictive of interpersonal distress and depression and to replicate previous research that suggests that hostility is a risk factor for other health behaviors (e.g., smoking and excessive alcohol use) and psychosocial health problems. We use data from the youngest generation of a three-generation, 11-year follow-up study of Mexican Americans, that represent 251 Mexican Americans between the ages of 18 and 42 years. Our indicator of hostility was the irritability subscale from the Buss-Durkee Hostility Inventory. After statistically controlling for marital status, language acculturation, education, age, and sex, irritability was found to predict subsequent heavy drinking, somatic symptoms associated with depression, psychosomatic symptoms, infectious disease, divorce, marital separation, ending a serious nonmarital relationship, not being married at the follow-up, and more negative feelings associated with divorce, marital separation, and ending a serious relationship. Our research supports theory and research suggesting that hostility is predictive of physical symptoms, poor health habits, and interpersonal conflict.

Adolescent↗
PubMedDate not supplied

Physical and psychosocial consequences of stroke in elderly Mexican Americans.

OBJECTIVE: The current study examines the psychosocial and physical predictors and consequences of stroke among elderly non-institutionalized Mexican Americans. DESIGN: A cross-sectional cohort study design was used. SETTING: The sampling frame included the Southwestern United States (Arizona, California, Colorado, New Mexico and Texas) where subjects were interviewed in their homes. PARTICIPANTS: A probability sample consisted of 3,050 Mexican Americans aged 65 or older. MAIN OUTCOME MEASURE: The main outcome measure was self-report of being diagnosed by a physician as having a stroke that required hospitalization. RESULTS: Those who ever had a stroke (N=159) were less likely to be able to perform activities of daily living than persons who never had a stroke (N=2,869). Rates of disability and prevalence of stroke appear to be higher in elderly Mexican Americans than in the general elderly population. Greater education and language acculturation were risk factors for having a stroke. CONCLUSIONS: The finding that Mexican Americans who are less acculturated are more healthy suggests that acculturation may increase morbidity and, potentially, mortality from stroke.

Acculturation↗