Search PubMedSearch

Biomedical subjects

C Meyerowitz

Publications and source records attributed to C Meyerowitz.

At least 19 recordsLinked to original sources

Evaluation of myocardial ischemia using a rest metabolism/stress perfusion protocol with fluorine-18 deoxyglucose/technetium-99m MIBI and dual-isotope simultaneous-acquisition single-photon emission computed tomography.

OBJECTIVES: This study sought to develop a dual-isotope single-acquisition single-photon emission computed tomographic (SPECT) protocol using a multihead SPECT camera equipped with an ultra-high energy collimator to evaluate rest metabolism/stress perfusion simultaneously with fluorine-18 (F-18) deoxyglucose/technetium-99m (Tc-99m) 2-hexakis-2-methoxy-2-methylpropyl isonitrile (MIBI). BACKGROUND: The most accurate and logistic method of identifying injured but viable myocardium remains a diagnostic challenge. METHODS: Sixty-five patients were given 25 to 50 g of glucose and, after approximately 60 min, an injection of 370 MBq (10 mCi) of F-18 fluorodeoxyglucose. After a 35-min distribution phase, patients underwent exercise or pharmacologic stress followed by administration of 925 MBq (25 mCi) of Tc-99m MIBI. Five patients underwent F-18 fluorodeoxyglucose position emission tomography before dual-isotope SPECT: RESULTS: With a window of 20% for both photopeaks and a technetium-99m/fluorine-18 concentration of 3.2:1, the "spillover" from fluorine-18 into the technetium-99m window is < 6% of the total counts in the window in patients with a normal distribution of both radiopharmaceuticals. Phantom images clearly demonstrated cardiac defects measuring 2 x 1 and 2 x 0.5 cm. There was no significant difference in the images of the five patients who underwent both positron emission tomography and SPECT: Fifty-seven patients (mean [+/- SD] age 55 +/- 15 years, range 25 to 83; 38 men, 19 women) had satisfactory images and were included in the study. Twenty-one patients had normal study results; 15 had mismatched defects; 14 had matched defects; and 7 had both matched and mismatched defects. Twenty-three patients (mean age 54 +/- 6 years, range 30 to 83; 14 men, 9 women) underwent coronary angiography within 3 months of dual-isotope SPECT: There were seven normal studies, eight with mismatched defects, one with a matched defect and seven with matched and mismatched defects. When stenosis > 70% was used as the criterion for a diagnosis of coronary artery disease, dual-isotope SPECT had a sensitivity of 100%, specificity of 88%, positive predictive value of 93%, negative predictive value of 100% and an accuracy of 96%. CONCLUSIONS: Dual-isotope SPECT may provide an alternative, accurate, cost-effective method to nitrogen-13 ammonia/F-18 fluorodeoxyglucose positron emission tomography or thallium-201 reinjection for identifying injured or dysfunctional but viable myocardium.

Coronary Angiography

Optimal cutoff levels of F-18 fluorodeoxyglucose uptake in the differentiation of low-grade from high-grade brain tumors with PET.

PURPOSE: To determine the optimal cutoff level of fluorine-18-labeled fluorodeoxyglucose (FDG) uptake in the differentiation of low-grade from high-grade cerebral tumors at position emission tomography (PET). MATERIALS AND METHODS: The authors retrospectively reviewed images from PET, magnetic resonance imaging, and computed tomography performed in 58 consecutive patients with histologically proved brain tumors. There were 32 high-grade tumors (20 gliomas) and 26 low-grade tumors (18 gliomas). RESULTS: The best cutoff level of FDG uptake ratios in the differentiation of high-grade from low-grade tumors was 1.5 for tumor-to-white matter (T/WM) ratios and 0.6 for tumor-to-cortex (T/C) ratios. These levels were the same when only gliomas were analyzed and when all tumors were analyzed. When a T/WM ratio of more than 1.5 was considered indicative of a high-grade tumor, the sensitivity and specificity were 94% and 77%, respectively. The results were similar for the T/C ratio. CONCLUSION: Cutoff levels of 1.5 for the T/WM FDG uptake ratio and 0.6 for the T/C ratio are useful in the differentiation of low-grade from high-grade gliomas with PET.

Adult

Preliminary results of a pilot study using WR-2721 before fractionated irradiation of the head and neck to reduce salivary gland dysfunction.

PURPOSE: Based on in vivo evidence of radioprotection of the salivary glands using WR-2721, a pilot study was undertaken to determine the feasibility, toxicity, and salivary function of patients receiving WR-2721, while undergoing radiation therapy to the head and neck. METHODS AND MATERIALS: Patients undergoing radiation therapy for cancer of the head and neck were eligible if the major salivary glands received more than 45 Gy. WR-2721 was administered over 6 min IV, 10-15 min prior to each dose of radiation five times per week. Saliva was collected and measured prior to radiation therapy, weekly during radiation therapy, 1 month postradiation therapy, and every 3 months thereafter. Flow rates of unstimulated whole saliva, stimulated whole saliva, and stimulated parotid saliva were measured using standard techniques. 99mTc salivary scintiscans were performed prior to radiation therapy, 1 month postradiation therapy and every 3 months thereafter. Nine patients are presently enrolled on the first dose level (100 mg/m2) of this study. Eight completed per protocol, two with minor decreases of total WR-2721 doses. Two patients progressed with distant metastases soon after completion of therapy. All available data are included in the analysis. Median follow-up for all patients is 18 months. RESULTS: Flow rates of unstimulated whole saliva decreased significantly during radiation therapy reaching 5.6% of baseline at 9 months postradiation therapy, subsequently recovering to 20% of baseline, then remaining stable over time. Stimulated whole salivary flow rate similarly decreased during radiation therapy and reached its nadir (11% of baseline) at 3 months postradiation therapy, improving to 27% of baseline by 2 years. The stimulated parotid flow rate decreased during radiation therapy to 1.4% of pretreatment levels. Significant recovery took place 6 months postradiation therapy and by 18 months values had recovered to 54% of baseline. 99mTc salivary scintiscans confirmed this rebound of parotid function postradiation therapy. Toxicity was minimal with the exception of one patient who received only 27% of the planned total drug dose due to grade 3 hypotension after the eighth treatment. No recovery of salivary function has been seen in this patient; flow rates remain zero in all three areas tested 21 months after radiation. CONCLUSIONS: Administration of WR-2721 prior to each dose of radiation was feasible and without significant toxicity at 100 mg/m2. Salivary gland function improved over time after completion of radiation, particularly the parotid. Future directions include escalation of WR-2721 dose to 200 mg/m2 and then 300 mg/m2, and a Phase III randomized trial will be undertaken once the optimal dose is established.

Amifostine

Practice characteristics of graduates of postdoctoral general dentistry programs.

A mail questionnaire was sent to 900 dentists who completed a Postdoctoral General Dentistry (PGD) program in 1985 and 900 dentists who graduated from dental school in 1985 but did not participate in a PGD program. The response rate was 57 percent. Three-quarters of the PGD graduates trained in civilian programs with the remainder being equally divided between military and Veterans Administration (VA) programs. Graduates of military programs continued to be employed by the military five years after graduation in contrast to the VA where less than 2 percent of graduates were employed after five years. The percent of dentists who are specialists or are enrolled in specialty programs five years after graduation was approximately 13 percent and the rates were similar for PGD and non-PGD dentists. The patterns of care in private practice tended to be similar for both groups; however, in institutions GPR graduates provided more treatment for special care patients and patients who were economically disadvantaged. GPR graduates also were more involved in teaching and in hospital activities.

Community Health Centers

A case for early surgery in native left-sided endocarditis complicated by heart failure: results in 203 patients.

From January 1982 to December 1988, 203 consecutive patients were selected for early valve replacement (mean 10 days from time of admission) if they had clinical evidence of native valve endocarditis with 1) vegetations on echocardiography, 2) severe valvular lesions, and 3) heart failure. Surgery was performed within 7 days of admission in 56% of patients and was done urgently because of hemodynamic deterioration in 108 (53%). All vegetations were identified by echocardiography and confirmed macroscopically at surgery. One hundred ten patients had isolated aortic valve infection, 50 had isolated mitral valve infection (p less than 0.05 for aortic vs. mitral) and 43 had double-valve infection. Mean aortic cross-clamp time was 57, 38 and 67 min, respectively. Sixty-four patients (32%) had extensive infection involving the anulus or adjacent tissues, or both; such infection more frequently involved the aortic than the mitral valve (p less than 0.05). Thirty-eight patients (35%) with aortic valve infection had abscess formation compared with 1 patient (2%) with mitral valve infection (p less than 0.05). Only eight patients (4%) died in the hospital. There were seven patients (3%) with a periprosthetic leak and five patients (3%) with early prosthetic valve endocarditis. Long-term follow-up, available in 174 hospital survivors (89%), revealed 10 deaths and two new ring leaks at 38 +/- 22 months. In conclusion, among patients with endocarditis who need surgery for heart failure, aortic valve infection is more prevalent than mitral valve infection and is more often associated with extensive infection, including abscess formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Use of an intra-oral model to evaluate 0.05% sodium fluoride mouthrinse in radiation-induced hyposalivation.

The present study was undertaken to evaluate the effect of a twice-daily topical application of a 0.05% NaF mouthrinse on de- and remineralization in the oral cavities of subjects suffering from radiation-induced hyposalivation. Six subjects each wore a bonded intra-oral appliance containing a sound and a demineralized human enamel slab for four weeks. During that period, the subjects used 0.05% NaF rinses, twice daily, instead of the 1.1% NaF gel that had previously been a part of their preventive regimen. Salivary flow rates, plaque pH profiles following a 10% sucrose rinse, S. mutans and lactobacillus counts, fluoride clearance, and enamel microhardness were determined during the study. Sound enamel samples displayed no evidence of demineralization, and the previously demineralized enamel showed remineralization in the outer 50 microns in three of the six subjects. The results suggest that a twice-daily oral rinse with 0.05% NaF can prevent demineralization and enhance remineralization in subjects with radiation-induced hyposalivation.

Bacteria

Geriatric dentistry and prevention: research and public policy (reaction paper).

The population of older adults is heterogeneous and can be divided into many subgroups: the young-old, the old-old, the healthy, the sick, the frail, the mentally and physically handicapped, the ambulatory, the chair-bound, house-bound or institution-bound, and the economically advantaged and disadvantaged. This diversity is extremely important to the discussion of the oral health needs, preventive health strategies, and research agenda for the elderly. As life expectancy increases, more attention is being paid to disease prevention so that the quality of life in old age can be improved. However, the link among oral health, systemic disease, and quality of life in the elderly needs to be better-defined. There is some evidence in the literature that indicates that coronal and root caries appear to be major health problems for the elderly. This needs to be corroborated in longitudinal studies. Although periodontal disease prevalence and severity are high in some subgroups of the elderly, these appear to be in decline in the general population. Dental health-care workers must be cognizant of the oral conditions associated with systemic disease and the use of medication, a major concern in older adults. Prevention of oral disease in the elderly requires early intervention, education of the dental health team, and innovative uses of well-established preventive agents such as fluoride. An extensive research effort is needed to answer basic and applied questions regarding the oral health needs of the elderly. Federal and private funding will be necessary. The dental profession will have to demonstrate and be persuasive that money spent on research and care for the elderly is money well spent.

Aged

Extraction of the third molar and patient satisfaction.

Patient satisfaction is an important outcome measure of health care. This study was designed to evaluate patient satisfaction with extraction of the third molar in relation to certain criteria involving structure, process, and outcome. A 16-item patient-satisfaction questionnaire was developed and mailed to 262 patients who had third molars extracted in a university-based clinical department during an 18-month period. The returned questionnaires were subjected to a factor analysis by means of the varimax method; the analysis yielded three "clusters" that we labeled "general satisfaction," "interpersonal satisfaction," and "satisfaction with cost." Two-tailed Student's t tests were used to relate the clinical data to each area of satisfaction. There were a total of six statistically significant interactions in the data matrix at the 0.05 level. Three of these pertained to general satisfaction and three to interpersonal satisfaction. The methods used in this study can be used to relate components of patient satisfaction to elements of dental care.

Consumer Behavior

Retention of topical fluoride in the mouths of xerostomic subjects.

The total fluoride concentration in unstimulated whole saliva was measured before and at selected intervals after a self-applied 1.1% neutral NaF topical fluoride gel or use of a 0.05% neutral NaF fluoride mouthrinse in both normal individuals and patients with radiation-induced xerostomia. As expected, the gel resulted in higher peak fluoride values than the rinse and was retained in the mouth for longer periods of time in both groups. The xerostomic group expressed a mean oral fluoride concentration of 575 micrograms fluoride per gram of saliva within 1 min after the gel application and 150 micrograms/g following use of the mouthrinse, whereas the normal group exhibited peak concentrations of 112 and 71 micrograms/g, respectively, within 1 min after the same two treatments. The initial high levels of fluoride observed in normal subjects following the gel application decreased rapidly to less than 1 microgram/g within 2 h, whereas fluoride levels in the xerostomic subjects remained elevated above 12 micrograms/g for longer than 2 h. Similarly, following use of the mouthrinse, normal subjects' saliva fluoride levels decreased to less than 1 microgram/g within 1 h, whereas xerostomic subjects' saliva fluoride levels remained above 4 micrograms/g for longer than 2 h.

Adult

An educational consultative model for general practice training programs.

A behavioral science consultant has been retained by two hospital-based general practice residency (GPR) programs and one advanced program in general dentistry at the University of Rochester, and Eastman Dental Center, NY. This consultant is available throughout the year and serves as an external consultant who knows the programs well, and can be used as a source of information on various existing and potential issues and problems. The model used by the consultant has been inductive and is based on the expressed needs of faculty members, trainees, and directors. A number of issues or problems were identified, including faculty member morale, evaluation of residents' growth, resident and supporting staff relations, curriculum development, cooperation with other departments and institutions, and dealing with patients' anxiety to dental treatment. For each, a specific plan was developed. Various types of experiential techniques were used, including brainstorming, role playing, and taping and feedback. Didactic activities included minicourses and workshops in which standard teaching methods were used, such as lectures, seminar discussions, literature study, and demonstration. The model has evolved, and as each activity has succeeded, more faculty members have sought help from the consultant.

Consultants

The growth of postdoctoral general dentistry programs.

From 1972 to 1990, the number of Postdoctoral General Dentistry (PGD) programs increased by 57% and enrollment increased by 57% and enrollment increased by 131% for a total of 118 PGD programs and 1,367 positions. Although there has been some increase in military and Veterans Affairs (VA) programs, the major increase was in civilian programs. From 1972-78, the major impetus for growth was hospital sponsorship of General Practice Residency (GPR) programs. With federal funding of PGD programs, civilian GPR programs continued to be the main source of growth until the accreditation of Advanced Education in General Dentistry (AEGD) programs in 1981. Subsequently, almost all increases were in AEGD programs. Over the 12-year period of federal funding (1978-90), there was an increase of 406 civilian PGD positions to make a total of 925 positions. The increase in enrollment directly attributable to federal funding was 242. The "unmet demand" for PGD programs was estimated to be approximately 300 positions for 1990, from data derived from the Survey of Dental Seniors and the Matching Program. Assuming that the number of PGD positions continues to increase by 35 positions a year, as it has in the past 12 years, the unmet demand would be met in slightly less than 10 years. If, however, a postdoctoral year was mandated for licensure, the increase in the number of positions would be far short of projected need.

Education, Dental, Graduate