Biomedical subjects
Publications and source records attributed to B Jones.
The successful repair of a crushed cervical trachea using a composite microvascular graft is presented. The patient has been without a tracheostomy for four years.
The purpose of this paper is to describe, illustrate, and compare a number of different approaches to the analysis of repeated binary and categorical data. These approaches include empirical generalized least squares and generalized estimating equations, as well as traditional log-linear modeling methods. It is shown that the interpretation of the parameters in the various models depends critically on the type of model fitted. In particular, we contrast the population-averaged and subject-specific models. Two example data sets are used to illustrate the approaches, and throughout we concentrate on methods that can be easily implemented.
Iron bioavailability from species-specific milk is assumed to be high for the offspring, possibly due to species-specific iron-binding proteins in the milk. To assess this bioavailability using radioisotopes, the validity of extrinsic labeling technique needs to be proven. Using the suckling piglet as an animal model, we have compared iron bioavailability from sow's milk labeled extrinsically and intrinsically. During intrinsic labeling transfer into milk of 59Fe given intramuscularly was slow and was found to be at maximum 14 h post-injection. Recovery of isotope in the milk was only 0.00014%. Extrinsic and intrinsic labels were distributed differently among milk fractions; intrinsic iron bound primarily to the fat fraction but the extrinsic iron bound primarily to the casein fraction. Iron retention from intrinsically labeled milk was considerably higher than from extrinsically labeled milk. These results show that the extrinsic tag method is not valid for studies on iron absorption from sow's milk and suggest that the situation may be the same for human milk.
Neuropathic (Charcot) arthropathy of the spine is a relatively rare problem that, nonetheless, must be considered in the differential diagnosis of any patient with degeneration of one or more levels of the spine associated with diminished or absent protective sensation. This study presents 15 patients in whom Charcot arthropathy of the spine developed after traumatic paraplegia. Eight were successfully treated with surgical fusion, and the remaining seven were treated nonoperatively. By the use of combined anterior and posterior fusion with extensive debridement, autogenous grafting, and posterior instrumentation, successful fusion can be achieved in patients with Charcot arthropathy of the spine. However, the surgical technique is demanding, the rehabilitation must be carefully supervised, and the postoperative complication rate remains high. The possibility of developing secondary levels of arthropathy below a previously successful fusion must be considered.
In the decade since the early 1980s, the increasing use of immunosuppressive therapy for cancer and autoimmune disease, as well as for organ transplantation, has combined with the acquired immunodeficiency syndrome epidemic to increase greatly the incidence of opportunistic infections and other complications of the gastrointestinal tract. Consequently, barium fluoroscopic and cross-sectional imaging studies tailored to address these problems are no longer uncommon. Although overlap exists, there are radiographic patterns that can direct the diagnosis to an opportunistic infection and sometimes to a specific pathogen. This article describes and illustrates the radiographic findings of gastrointestinal superinfection with Candida albicans, cytomegalovirus, Cryptosporidium spp, herpes simplex virus, Mycobacterium tuberculosis, M avium-intracellulare, and human immunodeficiency virus. Other gastrointestinal tract complications of immunosuppression are discussed, including graft-versus-host disease following bone marrow transplantation, typhlitis, and pseudomembranous colitis.
Few reports have described in detail the injuries that occur to the oral cavity, pharynx, and larynx following caustic ingestion. The role of dynamic radiographic studies to delineate the extent of damage has been minimized. In-depth radiographic analysis of such cases has not, to our knowledge, been previously reported. In order to examine the injuries and functional abnormalities of these sites following caustic ingestion, the records of The Johns Hopkins Swallowing Center were reviewed. Five patients were identified as having significant upper aerodigestive tract caustic injuries. All patients had dysphagia, epiglottis injuries, and incomplete laryngeal protection with aspiration. Four of five had sustained some degree of esophageal stenosis. Also noted were pharyngeal muscle dysfunction, nasopharyngeal regurgitation, tongue fixation, and hypopharyngeal stenosis. Roentgenographic findings are described and illustrated. The multidisciplinary approach to the management and rehabilitation of these patients is discussed.
Twenty patients with a remote history of poliomyelitis and recent or progressive dysphagia were evaluated with cinefluorography. Radiographic abnormalities were present in the pharynx in varying degrees in all but one of the patients. Findings included atrophy of the prevertebral soft tissues, unilateral or bilateral weakness of the tongue or soft palate, paresis or paralysis of the pharyngeal constrictor muscle, incomplete or absent epiglottic tilt, poor laryngeal elevation, poor laryngeal closure with laryngeal penetration, aspiration (often without a cough), and luminal narrowing at the cricopharyngeal level. Other structural lesions included a Zenker diverticulum in one patient, bilateral pharyngeal pouches in five, and a unilateral pouch in one. Additional structural lesions contributing to dysphagia were found in two other patients, including a focal stricture in the cervical esophagus in one patient and two stenotic rings in the distal esophagus in another. In four patients (one of whom had the Zenker diverticulum), the inferior constrictor muscle contracted forcibly above a prominent cricopharyngeus muscle, perhaps contributing to the formation of the diverticulum. It is important to examine postpolio patients with dysphagia carefully with dynamic imaging to assess the severity of decompensation and to detect other lesions that may be treatable. The information derived can be used to guide management.
OBJECTIVE: Our objective was to study the imaging findings in patients who had gastric and duodenal obstruction as a long-term complication of cholangiocarcinoma and to determine if the obstruction was associated with radiation therapy. MATERIALS AND METHODS: Between 1973 and 1989, 96 patients had either curative resection or palliative stenting for cholangiocarcinoma involving the hepatic duct bifurcation. Sixty-three (66%) also received adjuvant radiation therapy ranging from 4960 to 7220 rad (cGy). Gastric outlet or duodenal obstruction or both developed subsequently in seven of the 63 patients treated with radiation therapy. Radiographic studies, including upper gastrointestinal series and CT, and medical and surgical records for these seven patients were retrospectively reviewed. RESULTS: Upper gastrointestinal series in the seven patients with obstruction showed narrowing of the lumen, deformity and enlargement of gastric and duodenal mucosal folds, and delayed gastric emptying. CT performed in five of the seven patients showed thickening of the wall of the gastric antrum and small bowel and retained food and fluid within the stomach. All seven patients required gastrojejunostomy; at surgery, dense adhesions and fibrosis were found, and it was not evident whether the obstruction was due to the tumor or to radiation fibrosis. However, because this complication was seen only after radiotherapy, it was presumed to be radiation fibrosis. CONCLUSION: Our experience suggests that radiation therapy increases the risk of postoperative gastric and duodenal obstruction in patients undergoing surgery for cholangiocarcinoma.
Modern interest in craniosynostosis began when clinicians, regardless of their individual specialty but united in their interest in the problems raised by patients with this condition, first realised that if treatment was confined simply to opening up the fused sutures of the skull vault, success in terms of both function and the restoration of a more normal appearance was likely to be limited. Indeed, the grouping together of such specialists into formal craniofacial units was tacit recognition of this, as was the acceptance that many affected children had evidence of clinical problems that could not be explained on simple mechanical grounds alone. It is not surprising, therefore, that the advent of any new method of investigation has been welcomed by craniofacial surgeons eager to learn anything that might lead to an improvement in management, particularly of the more complex syndromes.
A nursing case management system was implemented on the medical-surgical unit of an 86-bed community hospital using a four-phase process. The development and implementation processes are described. Program evaluation indicated that the application of the model resulted in benefits for patients, care providers, and the institution.
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Gastrointestinal disease in two groups of immunocompromised patients, namely the AIDS patient and the post-bone marrow transplant patient, are discussed. Disease entities include opportunistic infections, Kaposi's sarcoma, lymphoma and other B cell proliferative disorders, cancer following transplantation, typhlitis, and pseudomembranous colitis.
Injuries were recorded during and up to 12 days after a maximal effort road march. Light infantry soldiers (N = 335) carried a total load of 46 kg over a 20 km course. Twenty-four percent of the soldiers suffered one or more injuries, resulting in 44 days of limited duty. All injuries involved the lower extremities and/or the back. Foot blisters and back problems were the most common complaints (35% and 23%, respectively, of the total injuries). These data indicate that units without recent road marching training can expect a high incidence of injuries as a result of a single demanding road march.
In 1971, Cancer and Leukemia Group B (CALGB) mounted a study of acute lymphocytic leukemia (ALL) that compared the effects of the two steroid hormones dexamethasone and prednisone. Six-hundred-forty-six children and adolescents with ALL were randomized to receive either prednisone or dexamethasone as part of their remission induction therapy. The 493 evaluable patients who achieved complete remission received the same steroid as pulses throughout remission. Specific central nervous system (CNS) therapy was randomized to either six injections of intrathecal methotrexate (IT MTX) alone or to six injections of IT MTX with cranial radiation (2,400 cGy). Both cranial radiation and dexamethasone offered increased protection against CNS relapse as the first site of failure over IT MTX alone. There were 30 CNS relapses among 238 patients (12.6%) receiving cranial radiation plus IT MTX, whereas there were 70 CNS relapses among 225 (P less than 0.001) (22.5%) in those who received IT MTX alone. Similarly, there were 33 CNS relapses among 231 (14.3%) children treated with dexamethasone, whereas there were 67 CNS relapses among 262 (25.6%) treated with prednisone (P = 0.017). Both steroids appeared equal in protecting the bone marrow. Recent national studies have shown significant improvements in preventing CNS relapse over the results in the present report. However, this finding warrants further investigation and, with further documentation, could lead to the substitution of prednisone by dexamethasone to aid further in preventing CNS relapse. This may be particularly important in patients at higher risk for CNS relapse.
A latent variable model for categorical data is described. The nuisance parameters in the model can be eliminated from the analysis through the use of a conditional likelihood and this leads to an analysis based on a log-linear model. It is shown how the structure of a cross-over trial allows considerable simplification in the formulation of this model and routine application of well-known statistical packages. The method is illustrated by data from a three-period cross-over trial on the relief of primary dysmenorrhea using the GLIM and SAS packages.
Radiographic features of the duodenal mucosa were analyzed in a series of 26 patients in whom the diagnosis of Brunner gland hyperplasis (BGH) had been established by endoscopic biopsies. The observed mucosal patterns could be classified into five categories: (1) focal BGH causing a solitary submucosal adenoma or a cluster of sessile polyps in the otherwise smooth duodenal bulb surface (five cases); (2) diffuse BGH manifested by a myriad of small and uniform mucosal elevations (six cases); (3) multifocal BGH producing large and well-demarcated polygonal masses (six cases); (4) BGH with concomitant acute and/or chronic duodenitis showing marked thickening and nodularity of duodenal folds (four cases); or (5) BGH with predominant erosive duodenitis, leading to ulcerations (five cases). These radiographic findings showed a good correlation with the endoscopic and histopathologic manifestations of BGH and the frequently coexistent duodenitis.
Review of the English literature revealed 21 cases describing abnormalities on barium enema secondary to amyloidosis of the colon. These cases were categorized as to frequency of specific barium enema findings and distribution within the colon. The most common radiologic findings were luminal narrowing (11 of 21), loss of haustrations (10 of 21), thickened mucosal folds (8 of 21), mucosal nodularity (8 of 21), and ulceration (6 of 21). The most frequent locations of disease within the colon were the descending and rectosigmoid portions (13 of 21). We present a case of primary amyloidosis that demonstrates the findings of bowel wall thickening and luminal narrowing on double-contrast barium enema and computed tomography (CT). Pathologic examination in our case, in addition to similar observations from the literature, suggests that at least a part of the radiologic changes of colonic amyloid can be attributed to bowel ischemia.