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Biomedical subjects

S Friedman

Publications and source records attributed to S Friedman.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1997

A carboxyl-terminal domain in fibroblast growth factor (FGF)-2 inhibits FGF-1 release in response to heat shock in vitro.

The fibroblast growth factor (FGF) prototypes, FGF-1 and FGF-2, lack a signal sequence, but both contain a nuclear localization sequence. We prepared a series of FGF-1 deletion mutants fused to the reporter gene, beta-galactosidase (beta-gal) and determined that a domain between residues 83 and 154 is responsible for FGF-1 cytosol retention in NIH 3T3 cells. Using a series of FGF-beta-gal chimeric proteins prepared by the shuffling of cassette-formatted synthetic FGF prototype genes, we were able to demonstrate that the nuclear localization sequence from the 5'-CUG region of FGF-2 is not able to direct the nuclear association of FGF-1 due to its inability to repress the function of the FGF-1 cytosol retention domain. We also observed that while the FGF-1:beta-gal chimera was released in response to heat shock, the FGF-2:beta-gal protein was not. Further, replacement of the FGF-1 cytosol retention domain with the corresponding domain from FGF-2 repressed the release of the chimeric protein. These data suggest that the specificity of the stress-induced secretion pathway for FGF-1 involves a carboxyl-terminal domain that is absent in FGF-2 and that the FGF-1 secretion pathway does not restrict the release of high molecular weight forms of FGF-1.

3T3 Cells↗
PubMed1997

Comparison of injury during cadet basic training by gender.

OBJECTIVES: To describe the rate and distribution of injuries during basic training in male and female cadets and to assess the contribution of pretraining conditioning and height to the male-female differential in injuries. DESIGN: Cohort study. SETTING: The US Military Academy, West Point, NY. PARTICIPANTS: A total of 558 cadets from the class of 1995 at the US Military Academy. MAIN OUTCOME MEASURES: The rate of injuries resulting in 1 or more days excused from physical activities per 100 cadets and the rate of injuries resulting in hospitalization of 1 night or longer per 100 cadets. RESULTS: Women had 2.5 times the rate of injuries as men and 3.9 times the rate of injuries resulting in hospitalization. Women had significantly more stress fractures and stress reactions than men. The median number of days excused from physical activities for women's injuries was significantly higher than that from men's injuries. Pretraining conditioning, measured by performance on a 2-mile (3.2-km) run, accounted for approximately half the difference in rates of injuries between men and women; differences in height among men and women did not account for differences in injury rates. CONCLUSIONS: The women had a higher risk for injury during military training than men. Increased pretraining conditioning may substantially decrease the risk for injury.

Adolescent↗
PubMed1997

Effect of the vaccines for children program on inner-city neighborhood physicians.

OBJECTIVE: To determine the probable effect of the Vaccines for Children (VFC) program on immunization coverage. DESIGN: Preintervention and postintervention study design, with data collected before and after enrollment in the VFC program. SETTING: Twenty-three inner-city neighborhood physicians' offices in New York City. PARTICIPANTS: In 1993, 30 physicians were randomly selected from 8 neighborhoods with the highest proportions of Medicaid-eligible individuals in New York City. In 1995-1996, the 30 physicians were contacted again. Twenty-three agreed to an interview and medical record review. Within each office, the medical records of children aged 3 to 35 months, with at least 3 visits in a 3-month or longer period, were randomly selected. Medical record reviews were conducted for 173 eligible children in 1993 and 528 in 1995-1996. INTERVENTIONS: The VFC program was implemented in October 1994. The administration fee increased from $2 to $17.85; physicians received vaccines free. MAIN OUTCOME MEASURES: Up-to-date status for immunizations and lead and tuberculosis screening; percentage of visits that are missed opportunities to immunize; and percentage of visits that were well-child visits. Up-to-date status, missed opportunities to immunize, and well-child visits were compared across time using chi 2 analysis, corrected for the use of cluster sampling. RESULTS: Up-to-date status changed significantly before and alter enrollment in the VFC program (P < .05) for all immunizations and for lead and tuberculosis screening. For the diphtheria toxoid, tetanus toxoid, and pertussis vaccine, oral poliovirus vaccine, and measles, mumps, and rubella vaccine combined, coverage increased from 17.9% to 42.2%, up by 24.3 percentage points (P < .05). Missed opportunities to immunize did not change, but well-child visits increased from 15.0% to 21.6% (P < .05). Physicians generally attributed performance improvements to the VFC program and not to other competing hypotheses. CONCLUSIONS: The VFC program seems to be responsible for an increase in immunization rates among these physicians.

Child, Preschool↗
PubMed1997

Response to nutritional and growth hormone treatment in progeria.

Hutchinson-Gilford progeria syndrome (HGPS) is a rare condition with an unknown molecular defect. Patients with HGP progressively develop failure to thrive (FTT), alopecia, loss of subcutaneous fat, scleroderma, stiffening of various joints, and severe atherosclerosis. The median life span is 13 years, and the main cause of death is cardiovascular complications. There are few reports of endocrine and metabolic studies because of the rarity of this condition, and the response to long-term growth hormone (GH) treatment has not been described. We report the results of endocrine and metabolic studies performed to investigate the etiology of growth failure in five patients with HGP. Additionally, the response to nutritional therapy (NT) and GH treatment in three of these patients is presented. Our results suggest that elevated GH levels are characteristic of this disease and that an elevated basal metabolic rate (BMR) could be the cause of the FTT seen in HGP. Nonaggressive NT slightly improved weight gain and growth velocity (GV). Combined NT and GH treatment in three patients improved the GV, increased the levels of growth factors, and paradoxically resulted in decreased BMRs. However, the response to these therapies decreased over time and did not seem to prevent the progression of atherosclerotic disease.

Adolescent↗
PubMed1997

In vivo model for assessing the functional efficacy of endodontic filling materials and techniques.

Endodontic fillings were challenged with bacterial ingress in mandibular premolars of 4 beagle dogs. Groups 1, 2, and 3 (n = 9), had canals filled with gutta-percha and sealer, gutta-percha alone, and sealer alone, respectively. After 2 wk, pulp chambers were inoculated with plaque. Group 4 (n = 9) and group 5 (n = 5) had canals either filled as in groups 1 to 3 or unfilled, respectively, but not inoculated. Group 6 (n = 5) had canals unfilled and inoculated. Teeth were radiographed periodically for 14 wk, dogs terminated, and jaw blocks retrieved and processed for light microscopic examination. Rarefying osteitis appeared in group 6 at 3 wk and in groups 2, 3, and 5 at 11 wk. Periradicular inflammation was none, mild, or severe. Occurrence of severe inflammation in groups 1 to 6 was 0, 11%, 33%, 0, 60%, and 100%, respectively. Groups 1 to 3 combined differed significantly from group 4 (repeated-measures ANOVA, p < 0.05). This model could be used to assess the functional efficacy of endodontic fillings in vivo.

Animals↗
PubMed1997

Retained foreign bodies.

OBJECTIVE: To evaluate the frequency of occurrence and outcome of patients having retained foreign bodies after treatment in an urgent-care setting. MATERIALS AND METHODS: Closed case records from the files of the Medical Professional Mutual Insurance Company involving claims of retained foreign body were reviewed for a 7-year period. MAIN RESULTS: Thirty-two patients filed 54 claims against 32 physicians and 22 health care institutions. Defense costs were $298,906, and indemnity payments were $1,279,171. Glass was the most frequent retained foreign body, constituting 53% of claims. Despite the fact that glass is radiopaque, x-ray films were ordered for only 35% of these patients. Retention of glass fragments when no radiologic study was obtained resulted in unsuccessful defense of 60% of the claims and higher indemnity payments. Radiologic studies were ordered for only 31% of all patients. CONCLUSIONS: All wounds should be considered to be at risk for foreign body entry. Documentation in the medical record of wound exploration and patient follow-up, and ordering of plain films and other diagnostic imaging studies should be used more frequently toward this end.

Diagnostic Errors↗
PubMed1997

Characterization of the intergenic region which regulates the MspI restriction-modification system.

The 110-bp intergenic region between mspIM and mspIR, the genes encoding the MspI modification (M.MspI) and restriction (R.MspI) enzymes, respectively, was fused, in both orientations, with lacZ. Expression of a single-copy mspIM-lacZ fusion is more than 400-fold stronger than expression of an mspIR-lacZ fusion. M.MspI in trans represses expression of the mspIM-lacZ fusion by binding to the DNA but does not affect expression of the mspIR-lacZ fusion. Transcription start sites of the genes were identified, and a set of nonoverlapping promoters was assigned. DNase I footprinting showed that M.MspI binds to a site within the intergenic region that includes only the mspIM regulatory elements.

DNA Footprinting↗
PubMed1997

Inhibition of growth factor mitogenicity and growth of tumor cell xenografts by a sulfonated distamycin A derivative.

Interference with growth factor-receptor interactions may have particular relevance in efforts to intervene clinically in both autocrine and paracrine aspects of malignancy. Suramin is a synthetic anticancer agent that works, in part, by blocking the binding of growth factors to their receptors. While initial clinical trials have been encouraging, its use in clinical applications is associated with significant toxicities. Suradista is a novel sulfonated distamycin derivative that is also effective at complexing and inactivating growth factors and cytokines while remaining relatively nontoxic. The goal of this study was to compare the antineoplastic properties of suramin and Suradista. To achieve this, the effects of these compounds on growth factor induced mitogenesis in normal mouse fibroblasts and human umbilical vein endothelial cells were examined, as well as their ability to inhibit the growth of NIH/3T3 cells that had been transformed by the introduction of a fibroblast growth factor (FGF) 1 coding region (residues 1-154) fused to the signal peptide of the hst/KS3 gene (sp-hst/KS3:FGF1-154). In each case, Suradista was more effective than suramin in inhibiting mitogenesis in normal cells, as well as the growth of the transformed cells. Furthermore, Suradista was also shown to be as effective as suramin at inhibiting the growth of sp-hst/KS3:FGF1-154-transformed NIH/3T3 xenografts grown in athymic nude mice when given at only 50% the dosage used for suramin (50 mg/kg for Suradista versus 100 mg/kg for suramin). In summary, these results indicate that novel compounds acting like suramin may be developed as effective antineoplastic agents and may also prove to be of clinical benefit.

3T3 Cells↗
PubMed1997

On the "true-false" memory syndrome: the problem of clinical evidence.

A patient in twice-a-week psychoanalytic psychotherapy began to recover childhood memories of chronic sexual abuse, including oral, anal and genital penetration. These memories sometimes included bizarre content that created skepticism regarding their authenticity. However, this dubious quality was in marked contrast to the internal consistency, continuity, and emotional authenticity of the psychotherapeutic process. Criteria for attempting to distinguish between fantasy and reality are noted. Despite their tenuous nature, these criteria are important because, most frequently, they will be the only data available within the clinical situation.

Adult↗
PubMed1997

Internal bleaching: long-term outcomes and complications.

Internal bleaching with a 30 percent hydrogen peroxide solution is aesthetically very successful in the short term; however, in the long term, the success rate falls below 50 percent. This procedure is associated with a risk of external root resorption, documented both clinically and experimentally. The etiology of resorption and the effects of 30 percent hydrogen peroxide on dental tissues suggest that this chemical should be avoided. Internal bleaching is possible using sodium perborate mixed with water. The aesthetic outcome is still acceptable and the potential for resorption may be minimized.

Borates↗