Biomedical subjects
Publications and source records attributed to B Jones.
An unusual case of delayed severe fibrosis of the soft tissues of the neck following radiation therapy for squamous cell carcinoma of the oropharynx resulting in dysphagia and recurrent aspiration is reported. The patient's case history, radiographic findings, and speech-language pathologic evaluation are presented.
Although they are delayed, progressive symptoms occurring after polio have recently received considerable attention, dysphagia in patients who have had polio has not been well-studied. The findings of historical, neurologic, and cineradiographic examinations in 13 patients with dysphagia who had had polio are presented. Historical evidence indicates that progressive dysphagia is among the worsening problems encountered by some patients several decades after their acute polio illness. Thorough evaluation of dysphagia symptoms in patients who have had polio is indicated to determine optimal feeding management and to search for treatable contributing factors.
Accidents occurring on congested urban freeways can have enormous impacts in terms of lost commuter time. This paper presents an appropriate statistical analysis of urban freeway accident frequency and duration and discusses how this analysis can be used to guide management strategies that seek to reduce the traffic-related impacts of accidents. The findings and demonstration of analysis procedures should be of considerable value to ongoing and future studies in this area.
Fifteen consecutive patients undergoing transhiatal esophagectomy for esophageal carcinoma were studied cineradiographically to evaluate postoperative pharyngeal function. Cinepharyngo-esophagograms were obtained preoperatively and 1 week (range: 6 to 10 days) and 1 month (range: 18 to 52 days) postoperatively. One week after transhiatal esophagectomy, new radiographic swallowing abnormalities were identified in 10 patients (67%). The most common abnormalities observed were laryngeal penetration or aspiration (seven patients, 47%) and incomplete laryngeal elevation (five patients, 33%). Abnormal epiglottic tilt was seen in only two patients (13%). No postoperative pharyngeal retention and no cricopharyngeal obstruction to swallowed contrast was observed. One month after transhiatal esophagectomy, all radiographic swallowing abnormalities had resolved or improved. Laryngeal penetration or aspiration is common after transhiatal esophagectomy and is a consequence of diminished airway protection with incomplete laryngeal elevation rather than a result of esophageal obstruction with "spill-over" aspiration. These changes resolve or improve within the first postoperative month.
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The Health Care Financing Administration (HCFA) uses information from hospital bills, such as age, sex, and diagnoses, to estimate statistical models for the probability, or risk, of death during and after hospital stays. The average risk estimates (expected death rates) are compared with the actual death rates to identify potentially poor quality of care. However, the methods have been criticized as inadequate and an often cited reason is the failure to incorporate risk factors for mortality that are known from clinical research. This hypothesis was tested using a stratified, random sample of 41,963 Medicare patients in 84 hospitals. Many clinical measurements were abstracted for testing as possible risk factors, and a few (26) were identified as useful predictors of death using logistic regression. The estimated regressions accounted for 39% of the variation in mortality, a standard severity classification accounted for 29%, and a relatively simple classification of patients into 17 groups, based on diagnoses, accounted for 17%. The logistic regressions yielded more accurate estimated mortality rates than the severity classification, which in turn was superior to the estimation methods used by HCFA. The HCFA methods were found to be biased in identifying outlier hospitals and this bias can be removed or ameliorated by using clinical risk factors to predict mortality. It is possible to estimate the risk of death more accurately using clinical risk factors and to measure the quality of care.
After a survey of the state of laminitis research the authors conclude that none of the present concepts of the pathogenesis of laminitis unequivocally explains the basic clinical and morphological observations in this disease. There is therefore reason to consider the advances that have been made during the last decades in respect to the influence of various substances on the differentiation of cultured skin keratinocytes. The technique is available for studying hoof keratinocytes in a comparable way. Relevant literature on cultured skin keratinocytes is surveyed. Some of the results from experimental studies on skin keratinocytes have an obvious connection with observations in laminitis, a fact which has led the authors to hypothesize that laminitis may be a "multifactorial" disease and that it may be provoked by agents stimulating multiplication of hoof keratinocytes with consequent reduction of differentiation.
Radiologic findings in a patient with gastric antral vascular ectasia are described on computed tomographic scans, upper gastrointestinal series, and specimen radiographs. Findings include prominent, scalloped antral folds radiating to the pylorus and thickening of the gastric antrum. Pathognomonic red vascular folds, likened to stripes on a watermelon, can be seen endoscopically.
A method was developed to estimate tissue doses from the upper gastrointestinal fluoroscopy examination. It involved measuring the technical parameters of the clinical examination, partitioning the dynamic examination into a set of discrete x-ray fields, and generating corresponding tissue does tables with an existing computer program. Knowledge of the radiation exposures associated with each of the fields enabled the calculation of tissue doses for the entire dynamic examination. In this limited sample (eight patients), fluoroscopy times ranged from 108 to 183 seconds. Radiation exposures ranged from 2.3 to 7.2 mC/kg (9.1-28 R), thyroid doses from 0.15 to 3.5 mGy (15-350 mrad), uterine doses from 0.16 to 1.0 mGy (16-100 mrad), lung doses from 0.90 to 4.2 mGy (90-420 mrad), and active bone marrow doses from 0.81 to 5.4 mGy (81-540 mrad).
Pseudomembranous colitis (PMC) is an infectious colitis usually occurring as a complication of antibiotic use. The computed tomographic (CT) appearances of 26 patients with PMC were reviewed. Twenty-three patients demonstrated an abnormal bowel wall, with an average wall thickness of 14.7 mm (range, 3-32 mm); in three patients, bowel wall thickness was normal. Contrast material trapped between thickened folds corresponded to the broad transverse bands described on plain radiographs. Pancolonic involvement was seen in 13 cases, while seven patients had right-sided involvement only; three patients had bowel wall thickening limited to the rectosigmoid only. Although the CT appearance of PMC is not highly specific, the diagnosis may be suggested in the proper clinical setting.
Whole body leucine kinetics were examined in seven healthy young men while in a 14-h postabsorptive state (PAS) and after a 3.5-day fast (FS). Subjects received a primed constant intravenous infusion of L-[1-13C]leucine while resting for 3 h and then while exercising on a cycle ergometer at 45% maximal O2 uptake to exhaustion. Blood samples drawn during isotopic steady state were analyzed for 13C enrichment of leucine and alpha-ketoisocaproic acid, and expired gas samples were analyzed for 13CO2. Resting leucine flux was higher in the FS, and there was a slight increase in leucine oxidation. During exercise, leucine flux did not differ between PAS and FS but leucine oxidation rose markedly. In the FS, leucine oxidation was 25 +/- 7 (SD) mumol.kg-1.h-1 at rest and rose to 75 +/- 21 mumol.kg-1.h-1 during exercise; in the PAS, oxidation was 20 +/- 5 mumol.kg-1.h-1 at rest and 52 +/- 17 mumol.kg-1.h-1 during exercise. These data indicate that the high rate of leucine oxidation previously found during exercise was increased further by a 3.5-day fast.
Clinical, developmental and environmental factors were retrospectively studied in 14 adolescent murderers who had been referred to a forensic psychiatric clinic over an 11 year period. Results of these analyses were compared with findings from previous reports. The majority of subjects came from split families. There was a greater than expected degree of psychiatric illness in the adolescents. Previous psychiatric contact, antisocial behaviour and substance abuse were common among these adolescents. A tentative profile of adolescents who are likely to commit murder can therefore be drawn up, which may suggest direction for preventive action and rehabilitation.
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The authors were members of the first group of medical students to participate in a newly modified third-year surgery clerkship at the University of Kentucky College of Medicine. The primary teaching methodology of this clerkship is problem-based learning (PBL). In this type of learning experience, students work with paper cases as though they were actual patients, using a method similar to that which they will later use as residents or practising physicians. The students make the decisions themselves, formulating differential diagnoses, eliciting relevant items from a history and physical examination, proceeding with a diagnostic work-up, and creating a treatment plan. This problem-based method increases students' use of resources, improves their retention of information, and helps them develop time management skills. Although the students believe that the clerkship as a whole should offer more opportunities for hands-on experience, they found the PBL component of the clerkship highly motivating, intellectually stimulating, and experimentally satisfying.
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