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Biomedical subjects

S Friedman

Publications and source records attributed to S Friedman.

At least 91 records · Page 5Linked to original sources
PubMed1999

The shear bond strength of glass ionomer cement sealers to bovine dentine conditioned with common endodontic irrigants.

AIM: The aim of this in vitro study was to evaluate the shear bond strength of commercially available and experimental glass ionomer cement (GIC) sealers to dentine exposed to common endodontic irrigants. METHODOLOGY: The enamel of 90 bovine incisor crowns, randomly divided into nine equal groups, was ground to expose the superficial dentine layer. The exposed surface was conditioned with either: (i) distilled H2O; (ii) 2.6% NaOCl; or (iii) 17% EDTA followed by 2.6% NaOCl. Five cc of each irrigant was applied over a 30-second period. The following GIC sealers were tested: (i) Ketac-Endo; (ii) KT-308, an experimental sealer; and (iii) ZUT, a combination of KT-308 and an antibacterial agent (0.2% by weight). The test sealers were applied to form cylinders with a standardized contact surface area (17.8 mm2) on the conditioned dentine surfaces. Specimens were bench set for 90 min and stored in distilled water at 37 degrees C for 48 h, then tested to failure for shear bond strength (MPa) in an Instron machine. RESULTS: KT-308 and ZUT had significantly higher MPa values than Ketac-Endo (two-factor ANOVA, P < 0.0001), regardless of the dentine conditioning. All specimens conditioned with 17% EDTA and 2.6% NaOCl combined had significantly lower MPa values than those conditioned with water or 2.6% NaOCl alone (P < 0.02). CONCLUSIONS: It was concluded that the experimental sealers KT-308 and ZUT bonded better to bovine dentine than Ketac-Endo, and that the bond of all three GIC sealers was better with the smear layer present.

Adhesiveness↗
PubMed1999

Management of coexisting coronary artery and asymptomatic carotid artery disease: report of a series of patients treated with coronary bypass alone.

BACKGROUND: A retrospective chart review of 94 patients with asymptomatic high-grade carotid stenosis undergoing coronary bypass (and valve replacement in some cases) was performed to determine whether significant carotid lesions can be safely ignored in patients undergoing cardiac surgical procedures. These operations were performed during a 2-year period. PATIENTS AND METHODS: There were 55 men and 39 women, with an age range of 37-89 years. Seventy-one patients had unilateral high-grade carotid stenosis, 17 patients had bilateral high-grade lesions, and six patients had unilateral high-grade stenosis and contralateral occlusion. Associated medical problems were recorded and short-term follow-up was obtained. RESULTS: There was one perioperative stroke and no deaths in this group of patients. CONCLUSIONS: Although these data indicate that high-grade carotid stenoses may be safely ignored during cardiac surgical procedures, a multicentre prospective randomized trial is needed to determine the appropriate treatment of the patient with coexisting carotid and coronary artery disease.

Aged↗
PubMed1999

Clinical and sociocultural differences in African American and European American patients with panic disorder and agoraphobia.

Much attention has been paid to the study of panic disorder symptomatology among primarily European American populations. However, such research has not adequately generalized to include minority groups. The present study examined phenomenological differences between African American and European American patients with panic disorder with or without agoraphobia. African American (N = 48) and European American (N = 33) patients with panic disorder were assessed by structured interview and self-report questionnaires upon presentation to an anxiety disorders clinic for treatment. African Americans evidenced a higher rate of comorbid posttraumatic stress disorder (16% vs. 0%). European Americans reported having their initial panic attack at an earlier age than African Americans (21 vs. 29). In terms of discrete panic attack symptoms, African Americans reported more intense levels of numbing/tingling in extremities (4.3 vs. 2.5) as well as greater fear of dying (6.3 vs. 4) or going crazy (4.6 vs. 3) than European Americans. African Americans evidenced less satisfaction with social support (2.7 vs. 3.2), especially financial support (2.3 vs. 3.2), than European Americans. African Americans employed coping strategies such as counting one's blessings (1.9 vs. 1.4) and religiosity (1.9 vs. 1.2) more often than European Americans but evidenced less self blame (1.7 vs. 2). This study extends previous findings by showing that African Americans have a later age of onset as well as different coping strategies than European American patients with panic disorder.

Adaptation, Psychological↗
PubMed1999

Quality of life assessment in patients undergoing head and neck surgery as evaluated by lay caregivers.

OBJECTIVES/HYPOTHESIS: Rehabilitation following head and neck cancer surgery has steadily moved into the outpatient realm and become dependent on caregivers with no formal medical background (lay caregivers.) Satisfactory rehabilitation and quality of life (QOL) depend on successful relationships between patients and the lay caregivers. This study evaluates the QOL assessments of patients by themselves and their primary lay caregivers before head and neck surgery. STUDY DESIGN: Institutional Review Board-approved study using validated QOL assessment instrument. MATERIALS AND METHODS: The preoperative QOL status in 50 patients undergoing extensive head and neck surgery was evaluated using the self-administered Medical Outcomes Survey Short Form 36 (SF-36). The patient's primary lay caregiver (spouse, child, or friend) completed a similar questionnaire evaluating the patient's status. RESULTS: Thirty-three (66%) questionnaires were returned. Twenty-five (50%) questionnaire sets were successfully completed by both parties and employable for comparison. Sixty percent of the caregivers were within the 90% confidence interval of the patient's assessment for six or more of the eight parameters evaluated by the SF-36. Likewise, caregiver assessments for specific parameters were consistently congruent with patient evaluation, except for the parameters of bodily pain and general health, for which caregivers demonstrated a trend for overrating pain and underestimating general health. Caregivers of the same generation as the patient demonstrated significantly higher congruence (P = .007). Similarly, a trend for higher congruence was noted in patients with recurrent disease. CONCLUSIONS: The importance of the lay caregiver has increased in the era of greater outpatient rehabilitation. This pilot study indicates that QOL assessment by lay caregivers may be examined with existing instruments and highlights QOL parameters critical to both the head and neck surgery patient and his or her primary lay caregiver.

Adolescent↗
PubMed1999

Molecular phylogenetic and biogeochemical studies of sulfate-reducing bacteria in the rhizosphere of spartina alterniflora

The population composition and biogeochemistry of sulfate-reducing bacteria (SRB) in the rhizosphere of the marsh grass Spartina alterniflora was investigated over two growing seasons by molecular probing, enumerations of culturable SRB, and measurements of SO42- reduction rates and geochemical parameters. SO42- reduction was rapid in marsh sediments with rates up to 3.5 &mgr;mol ml-1 day-1. Rates increased greatly when plant growth began in April and decreased again when plants flowered in late July. Results with nucleic acid probes revealed that SRB rRNA accounted for up to 43% of the rRNA from members of the domain Bacteria in marsh sediments, with the highest percentages occurring in bacteria physically associated with root surfaces. The relative abundance (RA) of SRB rRNA in whole-sediment samples compared to that of Bacteria rRNA did not vary greatly throughout the year, despite large temporal changes in SO42- reduction activity. However, the RA of root-associated SRB did increase from <10 to >30% when plants were actively growing. rRNA from members of the family Desulfobacteriaceae comprised the majority of the SRB rRNA at 3 to 34% of Bacteria rRNA, with Desulfobulbus spp. accounting for 1 to 16%. The RA of Desulfovibrio rRNA generally comprised from <1 to 3% of the Bacteria rRNA. The highest Desulfobacteriaceae RA in whole sediments was 26% and was found in the deepest sediment samples (6 to 8 cm). Culturable SRB abundance, determined by most-probable-number analyses, was high at >10(7) ml-1. Ethanol utilizers were most abundant, followed by acetate utilizers. The high numbers of culturable SRB and the high RA of SRB rRNA compared to that of Bacteria rRNA may be due to the release of SRB substrates in plant root exudates, creating a microbial food web that circumvents fermentation.

Journal Article↗
PubMed1999

The impact of physician bonuses, enhanced fees, and feedback on childhood immunization coverage rates.

OBJECTIVES: The purpose of this study was to examine the effects on immunization coverage of 3 incentives for physicians--a cash bonus for practice--wide increases, enhanced fee for service, and feedback. METHODS: Incentives were applied at 4-month intervals over 1 year among 60 inner-city office-based pediatricians. At each interval, charts of 50 randomly selected children between 3 and 35 months of age were reviewed per physician. RESULTS: The percentage of children who were up to date for diphtheria, tetanus, and pertussis and Haemophilus influenzae type b; polio; and measles-mumps-rubella immunization in the study's bonus group improved by 25.3 percentage points (P < .01). No significant changes occurred in the other groups. However, percentage of immunizations received outside the participating practice also increased significantly in the bonus group (P < .01). Levels of missed opportunities to immunize were high in all groups and did not change over time. Physicians' knowledge of contraindications was low. CONCLUSIONS: Bonuses sharply and rapidly increased immunization cover-age in medical records. However, much of the increase was the result of better documentation. A bonus is a powerful incentive, but more structure or education may be necessary to achieve the desired results.

Child, Preschool↗
PubMed1999

Apexification & apexogenesis.

When there is pulpal involvement of permanent teeth with incompletely formed roots, techniques for the induction of apical closure should be completed before endodontic therapy is begun. Apexification is a method of inducing a calcified barrier at the apex of a nonvital tooth with incomplete root formation. Apexogenesis refers to a vital pulp therapy procedure performed to encourage physiological development and formation of the root end.

Adolescent↗
PubMed1999

Perforation repairs.

Management of instrument perforations in the periodontal ligament space during endodontic or restorative procedures is an ongoing problem in dentistry. The introduction of microscopes, new instruments and materials has resulted in more controllable and predictable surgical and nonsurgical outcomes. This paper discusses some of the newer techniques and materials used to manage perforations effectively.

Aluminum Compounds↗
PubMed1999

Post removal techniques used in nonsurgical endodontic retreatment.

Removal of posts from root canals is often a tedious and difficult procedure. Factors such as type of post, cement used, interradicular relation of post to canal walls and accessibility of post affects the eventual success. It is necessary, therefore, for the clinician to evaluate his or her ability to remove posts when contemplating retreating endodontic cases. This paper discusses and evaluates a new technique and instruments used to facilitate post removal in nonsurgical endodontics.

Dental Cements↗
PubMed1999

Applications for guided bone regeneration in endodontic surgery.

Regeneration of apical bony defects remains a significant problem in endodontic surgery. When a resorbable membrane is placed over a defect, it acts as a barrier between the defect and the overlying gingival tissue. This barrier membrane provides sufficient time for bone to regenerate while preventing the faster growing connective tissue from invaginating into the area. When new tissue replicates the structure and function of the lost tissue, then apical regeneration has occurred.

Absorbable Implants↗
PubMed1998

Systemic amyloidosis and the gastrointestinal tract.

Systemic amyloidosis is caused by a variety of different diseases and frequently involves the gastrointestinal tract. Each type of amyloid affects the gastrointestinal tract differently. This article reviews the unique pathogenesis, pattern of gastrointestinal disposition, diagnosis, and treatment of the five systemic amyloidoses, and discusses the gastrointestinal diseases that cause systemic amyloidosis: inflammatory bowel disease and familial Mediterranean fever.

Amyloidosis↗
PubMed1998

Apical extent of rotary canal instrumentation with an apex-locating handpiece in vitro.

PROBLEM: The Tri Auto ZX (J. Morita Co., Kyoto, Japan) is a cordless endodontic handpiece with a built-in apex locator that is programmed to reverse the direction of rotation when the file reaches a predetermined apical level or when torque becomes excessive. OBJECTIVE: The purpose of this investigation was to examine the apical extent of rotary canal instrumentation and the ability to maintain apical constriction with the Tri Auto ZX at different automated settings. STUDY DESIGN: In 60 extracted teeth, canals were measured to the apical constriction, first visually and then electronically with the Tri Auto ZX; then they were instrumented with nickel titanium rotary files. For the instrumentation, the automatic apical reverse mechanism of the handpiece was set to 1, 1.5, or 2; these settings correspond to different distances from the apical foramen. Instrumentation was carried out apically until rotation was reversed by the automatic apical reverse function; the instrumented length was then measured, and the canal was filled with gutta-percha and sealer. The integrity of the apical constriction was assessed by exposing the apical 4 mm of the canal and observing the dentin-cementum junction. Paired t-tests were used to compare the visually measured length, the electronically measured length, and the instrumented length for each tooth. RESULTS: On average, the electronically measured length was 0.54 mm shorter than the visually measured length (p < 0.05). When the automatic apical reverse mechanism's setting was 1, the instrumented length was 0.1 mm shorter than the electronically measured length; when the setting was 1.5, the instrumented length was 0.36 mm shorter than the electronically measured length (p < 0.01). Results were inconsistent when the setting was 2. CONCLUSION: Instrumentation with the automatic apical reverse feature set at 1 consistently approximated the apical constriction; however, the constriction was frequently enlarged.

Dental Alloys↗
PubMed1998

Ultrasonic root end cavity preparation assessed by an in situ impression technique.

PROBLEM: In vitro studies have demonstrated microfractures in resected roots after root end cavity preparation with ultrasonic tips. Such microfractures are of concern; however, they may be artifacts. OBJECTIVES: To assess the incidence of microfractures after ultrasonic root end cavity preparation in situ. STUDY DESIGN: Fifty-two roots in two cadavers were endodontically treated, the soft tissues excised, and the root ends exposed and resected. The resected root surfaces were replicated with polyvinylsiloxane impressions. Root end cavities were prepared with ultrasonic tips, then impressed a second time. The roots were retrieved; 25 were processed for direct SEM examination as were both the impressions of each root. The specimens were examined by stereomicroscope and scanning electron microscope. RESULTS: In the impressions, the resected and prepared surfaces appeared irregular, but none demonstrated microfractures. In contrast, 15 retrieved roots showed microfractures. CONCLUSIONS: Ultrasonic root end cavity preparation in situ did not cause root microfractures, and the impression technique could be clinically usable with minor modifications.

Artifacts↗
PubMed1998

The transition from Medicaid fee-for-service to managed care among private practitioners in New York City: effect on immunization and screening rates.

OBJECTIVES: This study examined the association between participation in Medicaid managed care and up-to-date coverage for childhood immunizations and screenings among private practice physicians serving New York City's poorest neighborhoods. METHOD: A random sample of 2174 children 3-35 months of age was drawn from 60 physician practices in 1995, and a cross-sectional analysis was used to compare up-to-date status for immunizations, and lead and anemia screening tests, for children cared for by managed care and nonmanaged care physicians. In 1996, an independent sample of 2380 children from the same practices was used to compare up-to-date status for individual children enrolled in Medicaid managed care and children predominantly enrolled in traditional fee-for-service Medicaid. Information from physician interviews augmented chart review data. Chi-square analysis and logistic regression were used. RESULTS: Physicians who participate in Medicaid managed care and those who do not had equal up-to-date coverage for immunizations (41.0 vs. 36.9%, p = .527), and lead (46.8 vs. 38.7%, p = .199) and anemia screening (63.2 vs. 56.5%, p = .272). Measures of the process of care were also similar for the two groups of physicians. Children themselves enrolled in Medicaid managed care appeared significantly more likely to be up-to-date than their nonmanaged care counterparts for immunizations (OR = 1.53, p = .027) and anemia screening (OR = 2.95, p = .000). CONCLUSIONS: Participation in managed care does not seem to change physicians' overall preventive care practice behavior. Available data did not reveal major differences in demographics or health status between individual children enrolled in managed care and those not enrolled. That children enrolled in managed care were better immunized and screened than those in fee-for-service Medicaid suggests that physicians receiving compensation under two payment systems may treat children differently depending on each child's mode of reimbursement.

Anemia↗
PubMed1998

Career trajectories and older men's retirement.

The idea of a long and stable career rewarded by retirement is a fixture of the American social ethos and political economy. The paradox is that many Americans' careers do not fit this image. Here, we examined how the structure of the career, as compared to only those circumstances proximate to retirement, is important for understanding career endings. Based on labor force histories drawn from the National Longitudinal Survey of Older Men, we observed that the occupational roles held through the mid and late career combine additively to influence retirement and disability experiences, with different conditions of work coming into play depending on the career stage. Occupational roles in the mid career also have long-term, indirect effects, operating through the onset of health problems and the adequacy of pension benefits. Although retirement and disability are not hinged to occupational mobility per se, these career endings are sensitive to major discontinuities in the career and work role in terms of unemployment and labor force mobility.

Aged↗
PubMed1998

Eating disorders and insulin-dependent diabetes mellitus (IDDM): relationships with glycaemic control and somatic complications.

This study was designed to assess (by means of a diagnostic interview based on DSM-III-R criteria) the prevalence of eating disorders in 69 insulin-dependent diabetic (IDDM) out-patients, and the relationship with somatic risks. We found no cases of anorexia nervosa or bulimia nervosa, current or lifetime, in male patients with IDDM. No female patients with IDDM had anorexia, and 4.8% had current and lifetime bulimia. Eating disorders not otherwise specified (bulimic type) were significantly more frequent in women than in men (lifetime incidence 43% vs. 21%; current incidence 33% vs. 5%), and generally occurred after the onset of IDDM. Self-reports of bulimic behaviours according to the Bulimic Investigatory Test of Edinburgh (BITE) were associated with high levels of glycosylated haemoglobin. There was no association between eating disorders (current or lifetime), with somatic complications being more likely to be explained by a long duration of illness and impaired glycaemic control.

Adult↗
PubMed1998

Susceptibility of Nd:YAG laser-irradiated root surfaces in replanted teeth to external inflammatory resorption.

Nd:YAG laser-induced modification of the root surface may inhibit development of external inflammatory resorption in replanted teeth. This study tested this hypothesis in vivo. The pulp chambers of six mandibular premolars in each of two dogs were accessed, inoculated with plaque, and sealed (Groups 1, 2). Two additional premolars in each dog were endodontically treated without inoculation (Groups 3, 4). After 2 weeks, teeth were hemisected and extracted. Each root had a 2 x 3 mm surface area denuded of cementum on the buccal and lingual surface. In Groups 1 (n = 12 roots) and 3 (n = 4), the denuded surfaces were wiped with 15% EDTA, coated with black ink, and irradiated with Nd:YAG laser (0.75 W, 15 pps, 300 microns tip, 20 s). In Groups 2 (n = 12) and 4 (n = 4), the surfaces were wiped with 15% EDTA, and rinsed with sterile saline for 20 s. Roots were replanted within 5 min. The dogs were perfusion-euthanised 10 weeks after replantation. Block specimens were removed, decalcified, embedded and horizontally sectioned (6 microns) at 180-microns intervals, resulting in 10 to 14 cross-sections of each root. From these, the middle five consecutive sections were stained with hematoxylin and eosin, and observed by light microscopy for occurrence of surface, inflammatory and replacement resorption on the denuded surfaces. No obvious differences were noted between the laser-irradiated and non-irradiated surfaces. Inflammatory resorption was frequent in Groups 1 and 2, and absent in Groups 3 and 4. Replacement resorption was minimal in Groups 1 and 2, and frequent in Groups 3 and 4. Differences between Groups 1 and 2, and between Groups 3 and 4 were not significant, whereas the differences between the two pairs of groups were statistically significant (chi-square and two-way ANOVA, P < 0.006). These results did not support the hypothesis, and questioned the clinical validity of the surface modification in Nd:YAG laser-irradiated dentin. Therefore, the clinical application of Nd:YAG laser to the root surfaces of replanted teeth is not warranted.

Analysis of Variance↗