Biomedical subjects
Publications and source records attributed to R G Williams.
Prophylactic treatment of Rocky Mountain spotted fever with a single dose of oxytetracycline was investigated in guinea pigs. Disease was prevented when treatment was administered shortly before expected onset. Relapses occurred when treatment preceded expected onset by 48 h or more.
Retroperitoneal fibrosis has been associated with a variety of sclerosing diseases. Among these is the variant known as retractile mesenteritis, which involves predominantly the mesentery of the small intestine and associated vessels; involvement of the mesocolon and the colon is less frequent. Two patients with a dominating clinical picture of colonic obstruction are described. The radiographic presentations were similar and should serve to remind radiologists and clinicians of this entity.
Commonly used surgical sponges and appliances all have standardized, readily recognized opaque markers visible on radiographs. When these markers are identified on postoperative radiographs, they should be assumed to represent retained surgical sponges or appliances. With the rare exception of thoracotomy dressings, these marked materials are seldom, if ever, used as external bandaging materials. AP and lateral radiographs should provide an immediate answer as to the location of any retained surgical device. The early recognition of these retained surgical sponges should eliminate most complications related to their presence.
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The Southern Illinois University School of Medicine has completed a five-year experience applying an objectives-based approach to an entire curriculum in a medical school setting. Approximately 250 students have worked and studied within the system, and three classes have been graduated. This paper describes the instructional system and the procedures for monitoring, maintaining, and improving it and provides available outcome data.
A review of medical records of unselected children in whom the otoscopic diagnosis of middle ear effusion was uncertain, showed that tympanometry resolved the diagnostic uncertainty with an accuracy of 88 per cent for the prediction of a dry middle ear and an accuracy of 85 per cent for predicting fluid in the middle ear. Tympanometry itself gave inconclusive findings in II per cent of cases. Tympanometry can greatly reduce the need for diagnostic aspiration of the middle ear.
Dogs inoculated with Rickettsia rickettsii developed a clinical syndrome ranging in severity from a mild febrile exanthema to death within six days after inoculation. The severity of the disease appeared to be dose-related, and the signs were comparable to R. rickettsii infection in humans on a clinical and hematological basis. Dogs were rickettsemic for 10 to 14 days after infection. In most animals the level of rickettsemia was greater than or equal to 10(2.5) guinea pig intraperitoneal 50% infectious doses (GPID50). Infected dogs responded serologically as determined by indirect fluorescent antibody methods and were protected when challenged six to 12 months later with 10(7.0) GPID50 of the homologous strain of R. rickettsii. The monocyte culture technique was successfully used for the detection of rickettsemia, and the results compared favorably with those obtained by the guinea pig inoculation method of isolation.
Beagle dogs inoculated with the agent of Rocky Mountain spotted fever, Rickettsia rickettsii, developed a clinical syndrome that extended from febrile exanthema to death and appeared to be dose related. Infected dogs were anorectic and lethargic and developed cutaneous lesions characteristic of Rocky Mountain spotted fever, including petechia, ecchymosis, edema, and necrosis. Hematologic changes after inoculation included anemia, leukopenia proceeding to leukocytosis, and thrombocytopenia. Changes in blood chemistry values included increases in serum alkaline phosphatase and cholesterol, and hyponatremia and hypochloremia. The prominent histopathologic change was necrotizing vasculitis. The canine disease is comparable with human Rocky Mountain spotted fever on a clinical, hematologic, biochemical, and pathologic basis, and may provide a model system for this disease in man. The results suggest the dog may be involved in the epidemiology of R rickettsii infections.
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Eight cases are presented in which the diagnosis of overriding of the tricuspid valve was made during life and the electrocardiographic, echocardiographic and angiographic features of the defect are presented. Four of the patients had dextrotransposition of the great arteries, three had normally related great arteries and one had corrected transposition. In each case there was hypoplasia of the right ventricle and a ventricular septal defect of the atrioventricular (A-V) canal type. The electrocardiogram in the cases with d-transposition was characterized by diminished right ventricular forces, left ventricular forces, left ventricular hypertrophy and a superior leftward frontal plane axis. The echocardiogram in seven cases demonstrated a septal leaflet of the tricuspid valve opening posterior to the septum into the left ventricle. In four cases the anterior leaflet of the tricuspid valve was shown crossing the plane of the interventricular septum as it opened in diastole. The diagnosis in five cases was made angiographically by a left ventricular injection in the left anterior oblique projection. In this view the septum was viewed tangentially and in diastole the negative silhouette of the tricuspid valve was seen straddling the interventricular septum. The presence of an overriding tricuspid valve can greatly complicate repair of intracardiac defects. The diagnosis of this A-V valve anomaly can be accurately made with the use of echocardiography and selective left ventricular angiography.
The early clinical recognition and assessment of cor pulmonale are frequently difficult. To evaluate the usefulness of echocardiographic measurement of right ventricular dimension and septal motion in assessing cor pulmonale, we studied 94 patients with cystic fibrosis of varying severity. There was a significant relationship between increasing right ventricular dimension index (RVDI) and (1) decreasing clinical score, vital capacity, forced expiratory volume in one second (FEV1), and maximal midexpiratory flow rate (MMFR); and (2) increasing residual volume and thoracic gas volume. There was no correlation between right ventricular dimension index and PaO2. These findings were supported by electrocardiogram and pathologic evidence of right ventricular involvement. Abnormal septal motion was observed more frequently in patients with severe obstructive airway disease as measured by decreased vital capacity, FEV1, and MMFR. The data show that there is echocardiographic evidence of mild right ventricular enlargement and/or hypertrophy much earlier in the course of cystic fibrosis than previously suspected and that the echocardiogram is a useful tool in the evaluation of cor pulmonale in patients with cystic fibrosis.
A study of all patients with cancer of the larynx in a population of 449,430 over ten years shows that supraglottic and epilaryngeal cancer has an almost equal incidence to glottic cancer. There is a relationship between urbanization and the incidence of cancer of the larynx, and between cancer of the larynx and bronchogenic carcinoma. A policy of radiotherapy with surgery held in reserve for supraglottic and epilaryngeal cancer failed at a general hospital, for reasons that have been discussed. Primary surgery is required for most cases of supraglottic and epilaryngeal cancer. Radiotherapy with surgery held in reserve is the most appropriate treatment for the great majority of glottic cancers. When radiotherapy failed to cure the disease palliation was achieved in only a small minority of the cases.
Current methods of ranking or scoring disability tend to be arbitrary. A new method is put forward on the hypothesis that disability progresses in regular, cumulative patterns. A model of disability is defined and tested with the use of Guttman scale analysis. Its validity is indicated on data from a survey in the community and from postsurgical patients, and some factors involved in scale variation are identified. The model provides a simple measurement technique and has implications for the assessment of individual disadvantage, for the prediction of progress in recovery or deterioration, and for evaluation of the outcome of treatment regimes.
The echocardiographic features of congenital left ventricular inflow obstruction are described in six patients. The echocardiograms in two patients with cor triatriatum were distinguished by normal mitral valve motion and an abnormal echo within the left atrium. In two patients with supravalvar mitral ring, in addition to abnormal mitral valve motion, an abnormal echo, presumably originating from the obstructive membrane, was located between the anterior and posterior mitral leaflets. In two cases of parachute mitral valve, mitral valve motion was abnormal. In one of these cases there were multiple mitral valve echoes similar to those found in supravalvar mitral ring. The echocardiographic identification of an obstructive membrane within the left atrium is difficult because of the occurrence of artifacts. However, membranes may be identified if careful scanning techniques are employed in patients in whom left ventricular inflow obstruction is suspected. The echocardiogram is useful in detecting mitral valve abnormalities in these patients and is valuable in cases where mitral valve replacement is contemplated.
Xenon-133 ventilation-perfusion scans and technetium-99m angiocardiograms were performed 47 times in 34 patients. All patients had ventricular septal defect (VSD), 17 with pulmonary artery band (PAB), 6 with isolated VSD, 4 with pulmonary valvar stenosis (PS), and 7 with transposition of the great arteries (d-TGA), VSD, and PAB. Patients with VSD had slightly depressed ventilation fraction of the left lung and slightly elevated perfusion fraction of the left lung, both before and after closure of the VSD. Patients with VSD and PAB had slightly depressed ventilation fraction of the left lung but perfusion fraction of the left lung that was either markedly elevated or markedly depressed. After closure of VSD and removal of PAB the perfusion abnormality returned toward normal in some patients but remained abnormal in most. The findings were similar in most patients with d-TGA. Ventilation-perfusion ratio was nearly normal in patients with VSD alone, both before and after closure of VSD. In patients with VSD with PAB the severe abnormality of ventilation-perfusion ratio returned toward normal after corrective operation but did not reach normal. There was no abnormality of distribution of perfusion along the cephalocaudal axis of the lung with the patient supine.
The separation of clindamycin 2-phosphate from clindamycin 3-phosphate, clindamycin 4-phosphate, clindamycin B 2-phosphate, and lincomycin 2-phosphate was achieved by liquid chromatography on triethylaminoethyl cellulose using a 254-nm monitor. The compounds have low molar absorptivities at 254 nm (smaller than 17), and UV detection is made possible by the high capacity support triethylaminoethyl cellulose. Linear peak height response versus concentration allows rapid quantitation of clindamycin 2-phosphate.
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