VTM--a new method of measuring ocular torsion using image-processing techniques.
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Biomedical subjects
Publications and source records attributed to S T Smith.
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OBJECTIVE: The objective of this study was to evaluate the usefulness of pretreatment assessment with ultrasonography in patients with endometrial carcinoma. STUDY DESIGN: Fifty patients with endometrial carcinoma diagnosed by endometrial biopsy or curettage were studied before hysterectomy, bilateral salpingo-oophorectomy, and selected lymph node sampling. Ultrasonographic criteria for determination of tumor grade, depth of myometrial invasion, uterine volume, and tumor volume were established. Tumor grade was compared with preoperative and postoperative pathologic diagnoses, depth of invasion was compared with postoperative pathologic evaluation, and uterine volume and tumor volume were compared with postoperative evaluation of tumor grade and depth of invasion. Data were analyzed by chi 2 testing, and, where appropriate, sensitivity, specificity, and accuracy of the ultrasonographic measurements were determined. RESULTS: The following statistically significant correlations (p less than or equal to 0.05) were found. Ultrasonography predicted tumor grade as accurately as preoperative pathologic evaluation did. Depth of invasion less than or equal to 50% or greater than 50% significantly correlated. Uterine volume less than or equal to 200 ml predicted less than or equal to 50% depth of invasion 28 of 32 times. Uterine volume greater than 500 ml was noted in six cases; five of these had grade 2 or 3 tumor and four had depth of invasion greater than 50%. Tumor volume less than or equal to 20 ml predicted a grade 1 tumor in 25 of 39 cases and depth of invasion less than or equal to 50% in 34 of 39 cases. Tumor volume greater than 20 ml correlated with a grade 2 or 3 tumor in 11 of 11 cases and a depth of invasion greater than 50% in seven of 11 cases. In 25 grade 1 tumors diagnosed postoperatively by pathologic study, none was associated with a tumor volume greater than 20 ml. CONCLUSION: Pretreatment ultrasonographic measurements should be of value in the management of patients with endometrial carcinoma.
OBJECTIVE: The purpose of this study was to examine the therapeutic effects of hyperbaric oxygen on radiation-induced soft tissue necrosis in patients who previously received treatment for a gynecologic malignancy. STUDY DESIGN: Fourteen patients whose necrotic wounds failed to heal after 3 months of conservative therapy were enrolled in a prospective observational study. Outcome of hyperbaric oxygen treatment was measured by resolution of necrosis. RESULTS: Fourteen patients underwent 15 courses of hyperbaric oxygen treatments. All those with radiation necrosis of the vagina alone or in association with rectovaginal fistula had complete resolution of necrosis with hyperbaric oxygen. Only one treatment failure occurred. CONCLUSION: Hyperbaric oxygen is a safe, effective, and well-tolerated treatment for radiation-induced soft tissue necrosis.
OBJECTIVE: To determine whether greater risk for anaphylactoid reaction from intravenous urographic contrast media exists in patients receiving beta-adrenergic blockers or in asthmatic patients. DESIGN: Case-control study. SETTING: Tertiary care, referral-based medical center. PATIENTS: Of 28,978 intravenous urographic contrast media procedures done from July 1987 to June 1988, 49 patients experienced moderate to severe anaphylactoid reaction. Medical records from these 49 reactors were compared with those from a control group matched for gender, age, and date and type of contrast study who received intravenous urographic contrast media without adverse reaction. MAIN RESULTS: Patients exposed to beta-adrenergic blockers or with asthma comprised 39% (19 of 49) of reactors, compared to 16% (13 of 83) of matched controls (odds ratio, 3.43; 95% CI, 1.45 to 8.15; P = 0.005). Exposure to beta-blockers was 27% among reactors and 12% in matched controls (odds ratio, 2.67; CI, 1.01 to 7.05; P = 0.036). Asthma was found in 12% of reactors and 4% of controls; after correction for beta-blocker use, asthma was also associated with increased risk for anaphylactoid reaction (odds ratio, 4.54; CI, 1.03 to 20.05; P = 0.046). Compared with nonasthmatic patients not taking beta-blockers, asthmatic patients were at greater risk for anaphylactoid reaction with bronchospasm (P = 0.02). Five of 13 reactors receiving beta-blockers became hypotensive, and three needed hospitalization. Compared with nonasthmatic patients not taking beta-blockers, patients exposed to beta-blocking drugs were almost nine times (odds ratio, 8.7; CI, 0.81 to 93.5; P = 0.075) more likely to be hospitalized after an anaphylactoid reaction. CONCLUSION: Increased risk for moderate to severe anaphylactoid reaction from intravenous urographic contrast media exists in patients receiving beta-adrenergic blockers or with asthma. These patients are appropriate target populations for efforts to reduce risk before intravenous urographic contrast media are administered.
An asymptomatic patient was discovered to have a large right atrial myxoma by transthoracic echocardiography. Preoperative considerations included the possibility of satellite lesions, left atrial origin, and a question of tricuspid valve involvement. Subsequent operative transesophageal echocardiography demonstrated single-stalk attachment in the right atrial septal wall and no satellite lesions. Doppler and color flow examination immediately following tumor removal aided in the decision not to perform tricuspid annuloplasty as there was no significant tricuspid regurgitation. The combined use of transthoracic and transesophageal echocardiography with Doppler and color flow imaging aids in the preoperative and intraoperative diagnosis and surgical management of right atrial tumors.
Peak acceleration of blood in the ascending aorta, an index of global systolic left ventricular (LV) function, can be measured noninvasively using a continuous wave Doppler velocimeter applied suprasternally. The feasibility of this approach as a tool for detecting improvement of LV function was studied in 16 patients with congestive heart failure (CHF). Measurements were made daily for 6 consecutive days. The daily variability of peak acceleration examined in 11 normal subjects was +/- 2 m/s/s. In 11 of 16 patients with CHF, peak acceleration increased more than 2 m/s/s by day 6 compared with day 1 (group 1). In 5 of 16 patients, peak acceleration remained unchanged (group 2). In group 1, peak acceleration was 11 +/- 1 m/s/s on day 1 and increased to 16 +/- 1 m/s/s on day 6 (p less than 0.001). In this group, CHF resolved by day 6 in 9 of 11 patients. In group 2, peak acceleration was 9 +/- 1 m/s/s on day 1 and remained unchanged through day 6. In these 5 patients, the signs and symptoms of CHF persisted through day 6. The results suggest that peak acceleration measured noninvasively with continuous wave Doppler can detect improvement of LV function in patients with CHF. The approach provides a simple and reliable bedside means for serial evaluation of LV systolic function.
In a multicenter study, 77 edentulous patients had mandibular augmentation with implants of purified fibrillar collagen combined with dense hydroxylapatite (Alveoform Biograft); 22 of these patients also had maxillary augmentation. Most patients had Class III or IV mandibular atrophy, and had outpatient surgery with the subperiosteal tunneling technique. Temporary splints were worn for 24 hours post-surgery. Mean ridge height was 15.3 mm before surgery and 19.5 mm after 12 months, an augmentation of 4.2 mm. Predictable compaction occurred largely in the first few months after denture loading. Most patients, surgeons, and prosthodontists assessed the results of the procedure as good to excellent at 1 year following implantation. Adverse experiences, largely dehiscence and paresthesia, tended to resolve over time. Sera from ten patients demonstrated antibodies to bovine collagen that were not clinically significant. Alveolar augmentation with collagen/hydroxylapatite achieved clinically significant results that compared favorably with those achieved with other types of ceramic implants.
Survival of three strains of Escherichia coli K12 was studied with respect to radiation protection by dithiothreitol (DTT). The three strains compared were AB2462 recA, AB2470 rec21 and their DNA repair-competent prototype, AB1157. The strains were incubated in 10 mmol dm-3 DTT for 60 min and allowed an expression period for SOS functions to appear which may have been induced by DTT. Following the expression period the DTT-incubated cells and incubated control cells were irradiated. When AB1157 cells were pretreated with chloramphenicol (200 micrograms cm-3) for a period of 30 min prior to addition of the induction media no increase in survival was seen. When catalase (0.1 mg cm-3) was added to the AB1157 cells prior to the induction media a decrease in the degree of induction was noted with an enhancement ratio (ER) of 0.893 (ER-1 = 1.12). Furthermore, DTT-treated AB2462 and AB2470 demonstrated no increase in survival when compared to control cells. In radiation experiments on either strain of E. coli with or without DTT present during irradiation, the following were observed: (1) survival of AB1157 was enhanced with a dose modification factor (DMF) of 1.7 with DTT present and 1.3 with pretreatment; (2) the rec mutants showed no change in survival at any dose with a DMF of approximately 1.0. Results indicate that, using our protocol, inducible repair is of more importance than free radical scavenging by DTT. Furthermore, DTT-treated AB2462 demonstrated no increase in survival when compared to control cells. In radiation experiments on either strain of E. coli with and without DTT present during irradiation, the following were observed: (1) survival of AB1157 was enhanced with a DMF of 1.7 with DTT present during irradiation and 1.3 with only pretreatment; (2) the recA and recB mutants showed no change in cell survival at any dose with a DMF of approximately 1.0. Results indicate that, using our pretreatment protocol, inducible repair is of more importance in protection than free radical scavenging by DTT.
Little information is available concerning the metabolic fate of radiation-induced thymine base damage products once they have been excised from DNA. The present study was an attempt to determine whether or not thymine-requiring mutants of Escherichia coli could grow on dihydrothymine (DHT) and thymine glycol (TG) by "salvaging" the altered thymines. A second test of thymine product utilization was prevention of thymineless radiosensitization. Results showed that very low growth of Thy- cells on DHT or TG could be explained by the presence of less than or equal to 1% contaminating thymine in the mixtures. Radiation dose-modification factors (DMFs) for thyA cells fed DHT or TG for 3 h were 1.38 +/- 0.28 and 1.26 +/- 0.24, respectively, whereas the DMF for 3 h thymine-starved cells was 1.63 +/- 0.05. The small (approximately 25%) amelioration of thymineless radiosensitization observed in DHT- or TG-fed cells could probably be explained by contaminating thymine in the medium. Although DHT is a normal metabolite in some cells, neither DHT nor TG could be used efficiently by thymine-requiring cells in the protocol presented.
To determine the rate and extent of recovery of left ventricular (LV) performance following acute myocardial infarction (MI), peak aortic blood acceleration was measured serially in 26 patients and in 11 normal volunteers with a continuous wave Doppler placed suprasternally. In patients, Doppler measurements were made 20 +/- 2 hours after the acute onset of chest discomfort and were repeated daily for 6 consecutive days. Infarction patients were divided into two groups. Group I consisted of 15 patients who did not have a previous MI and whose present course was not complicated by congestive heart failure (CHF). Group II consisted of 11 patients who had either a previous MI or developed CHF during the present admission. Peak acceleration in the normal volunteers showed minimal daily variations over a period of 6 days. Peak acceleration in the entire group of 26 MI patients increased from 13 +/- 3 m/sec/sec on the day of admission (day 1) to 18 +/- 6 m/sec/sec on day 6 (p less than 0.001). In group I, peak acceleration increased from 13 +/- 4 to 20 +/- 6 m/sec/sec between day 1 and day 6 (p less than 0.001). In group II, however, peak acceleration was 12 +/- 2 m/sec/sec on day 1 and increased to only 15 +/- 4 m/sec/sec on day 6 (NS). These results indicate that LV performance, based upon peak acceleration of blood in the ascending aorta, improves markedly within 6 days in patients suffering their first MI uncomplicated by CHF.(ABSTRACT TRUNCATED AT 250 WORDS)
A multicenter study was undertaken to evaluate a new alveolar ridge augmentation material composed of purified fibrillar collagen and particulate hydroxylapatite (PFC/HA). In a study of 77 patients and 99 reconstructed ridges, this material provided superior handling properties over HA alone as evidenced by its ease of surgical placement and manipulation, and the rarity of particle migration or displacement. Moreover, the rapid development of ridge firmness and stability allowed for the loading of dentures within three to six weeks. Prosthodontist evaluations and surveys of patient satisfaction showed great satisfaction with denture fit, comfort, esthetics, speech, and ability to masticate.
Since its commercial release, Zyderm collagen implant has been used to treat more than 200,000 subjects in the United States for soft-tissue contour defects and more than 250,000 patients internationally (including the United States). Approximately 3 percent of subjects' skin tested with Zyderm collagen experience localized hypersensitivity reactions to collagen, whereas approximately 1 percent of treated patients demonstrate symptoms of hypersensitivity at treatment sites. Of the latter treatment responses reported since the conclusion of clinical trials with Zyderm, 56 percent occurred following the first treatment, 28 percent following the second, 10 percent following the third, and 6 percent following subsequent exposures. The data indicate that most patients receive a median of three treatments (mean = 4.4) with Zyderm collagen, but most patients who are likely to develop sensitivity to Zyderm collagen appear to respond immunologically to the test implant or first treatment exposure. Examining these treatment responses, 45 percent of the patients reported an onset of symptoms within 10 days and 22 percent at more than 30 days following the last treatment with Zyderm collagen. Erythema was the sole symptom in 24 percent of cases, whereas erythema plus induration comprised an additional 42 percent. Antibodies against Zyderm collagen were detected in the sera of 88 percent of these subjects using an ELISA, but no reactivity was observed against human collagen. Sera from patients reporting only systemic symptoms were not found to have anticollagen antibodies. These data suggest that the relative risk of a hypersensitivity reaction to Zyderm collagen does not increase with multiple exposures, since patients who are going to develop an immune response to bovine collagen react with greatest frequency to initial injections of collagen. In animal models, Zyderm collagen was shown to be less immunogenic than other medical devices which are composed of bovine collagen. Specifically, comparative studies were conducted in which Zyderm collagen and hemostatic agents were implanted in the guinea pig subcutaneum: sera from animals treated with collagen-derived hemostatic devices possessed significant levels of anti-implant antibodies (titers greater than 640), whereas animals treated with Zyderm collagen mounted minimal responses (titers less than 40). Additional studies were conducted in which implant materials were compared in a guinea pig parietal (bony defect) model and in a rabbit hemostasis model: in both, Zyderm collagen demonstrated lower immunogenicity than commercial bovine collagen hemostatic agents. Histologic results from these studies showed Zyderm
A visual half-field presentation technique was used to assess hemispheric asymmetries in young, language-deficient, retarded children who had been taught a nonspeech graphic symbol system. Unlike most tachistoscopic and dichotic listening methods, the present method did not require verbal instruction or verbal responses. In addition, the subjects' explicit understanding of the need to fixate visually prior to stimulus presentation was not necessary. Meaningful graphic symbols were recognized more accurately when presented to the hemisphere associated with the dominant eye and hand. Recognition of meaningless symbols was best when they were presented to the nondominant hemisphere. There was a significant hemispheric specialization effect similar to what would be expected in older, normal subjects using traditional methods.
Good and poor readers in the third grade (age nine years) were examined on a test of immediate memory for word strings and on a version of the Token Test (De Renzi and Faglioni, 1978) to assess sentence comprehension. The poor readers made more errors than the good readers in recall of word strings and on some Token Test items. Those Token Test items that impose the greatest burden on short-term memory were the most sensitive to reader group differences; syntactic complexity alone did not distinguish the groups. The findings support other indications that poor readers make less effective use of working memory in processing spoken sentences than good readers; they do not indicate a syntactic deficit on the part of the poor readers.
Seventy-seven patients, presenting with radiation small bowel injuries at the University of Texas M. D. Anderson Hospital and Tumor Institute at Houston between 1962 and 1978, were analyzed retrospectively. The patients were divided into two categories: bowel bypass without resection, and resection of irradiated bowel. Each group was then analyzed for its short- and long-term complications. Ileocolectomy with end-to-end anastomosis was the surgical procedure of choice in those people undergoing resection. There was no difference in short-term complications noted between the two groups. The long-term complications of fistula formation and continued small bowel necrosis could be prevented by resection, as a primary procedure. The surgical details of ileocolectomy with end-to-end anastomosis are presented, along with an analysis of the complications encountered in both groups.
The language problems of reading-disabled elementary school children are not confined to written language alone. These children often exhibit problems of ordered recall of verbal materials that are equally severe whether the materials are presented in printed or in spoken form. Sentences that pose problems of pronoun reference might be expected to place a special burden on short-term memory because close grammatical relationships obtain between words that are distant from one another. With this logic in mind, third-grade children with specific reading disability and classmates matched for age and IQ were tested on five sentence types, each of which poses a problem in assigning pronoun reference. On one occasion the children were tested for comprehension of the sentences by a forced-choice picture verification task. On a later occasion they received the same sentences as a repetition test. Good and poor readers differed significantly in immediate recall of the reflexive sentences, but not in comprehension of them as assessed by picture choice. It was suggested that the pictures provided cues which lightened the memory load, a possibility that could explain why the poor readers were not demonstrably inferior in comprehension of the sentences even though they made significantly more errors than the good readers in recalling them.
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Fifteen patients with childhood onset of Hodgkin's disease were studied for prevalence and quantity of Epstein-Barr virus (EBV) antibody to learn about the relationship between infection with EBV and Hodgkin's disease. Findings indicated that, compared with normal child control subjects, prevalence of EBV antibody is not increased in Hodgkin's disease, but the quantity of antibody increases as the duration of Hodgkin's disease increases. It seems that EBV plays no role in the cause of Hodgkin's disease and that production of greater amounts of antibody relates to immunoregulatory defects associated with Hodgkin's disease.