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Biomedical subjects

A Kaufman

Publications and source records attributed to A Kaufman.

At least 37 records · Page 2Linked to original sources
PubMed1999

Student and faculty perceptions of problem-based learning on a family medicine clerkship.

BACKGROUND AND OBJECTIVES: The value of problem-based learning (PBL) in the preclinical years of medical school has been described widely in the literature. This study evaluates student and faculty perceptions of PBL during the clinical years of medical school, on a family medicine clerkship. METHODS: Students used a 4-point scale to rate clerkship educational components on how well learning was facilitated. Faculty narratives of their perceptions of PBL were reviewed. RESULTS: Educational components that involved active learning by students--clinical activity, independent learning, and PBL tutorials--were ranked highest by students. Faculty perceived that PBL on the clerkship simulated "real-life" learning, included more behavioral and population issues, and provided substantial blocks of student contact time for improved student evaluation. CONCLUSIONS: Students and faculty in a family medicine clerkship ranked PBL sessions higher than any other nonclinical component of the clerkship. In addition to providing students with opportunities for self-directed learning, the PBL sessions provide faculty with more contact time with students, thereby enhancing the assessment of students' learning and progress.

Clinical Clerkship↗
PubMed1998

Neutropenia and thrombocytopenia in three dogs treated with anticonvulsants.

Three dogs became lethargic and had poor appetites within 2 months after anticonvulsant treatment was initiated to control seizures. Dogs were neutropenic, thrombocytopenic, and anemic and had splenomegaly. Sensitivity to phenobarbital and related anticonvulsants may induce life-threatening leukopenia, thrombocytopenia, and anemia in dogs. Phenobarbital-induced neutropenia in these 3 dogs may have posed a risk for developing bacteremia. It is important for clinicians to be aware of adverse effects so that adequate precautions can be taken. A baseline hemogram should always be obtained before starting anticonvulsant treatment, and periodic hemograms should be obtained to monitor animals. Furthermore, client education should include instructions on recognizing signs of bacteremia, thrombocytopenia, and anemia.

Anemia↗
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

Structure and strength of low-mercury dental amalgams prepared with liquid Hg-47.4% In alloy.

Two low-mercury amalgams: (1) low-copper lathe-cut and (2) high-copper (Tytin) were prepared by amalgamation with liquid Hg-47.4% In alloy. The strength-structure relationship of these amalgams was investigated and compared with standard amalgams (i.e. amalgams prepared with the same powders and pure mercury). The matrix phase of the low-mercury amalgam was found to be depleted of mercury and may be thought of as In4Ag9 compound with some mercury dissolved, indicating that less mercury (compared with standard amalgam) combines with silver, thus producing a strong amalgam matrix. On the other hand, an increase was observed in the consumption of the initial gamma (Ag3Sn)-phase, leading to an increase of the tin released. As a result, the potential of [HgSn]-phase formation in low-mercury amalgams increases. The observed increase in the quantity of gamma2(Sn7-8Hg)-phase in low-copper amalgam, or its appearance in high-copper amalgam (where it is normally absent), contributes to a deterioration in the strength of the investigated amalgam. The conclusion drawn was that low-mercury amalgam may be prepared with liquid Hg-47.4%In alloy but, in order to eliminate gamma2-phase formation, novel and possibly tin-free amalgamable alloys should be developed.

Journal Article↗
PubMed1998

Stability of access resistance during haemodialysis.

BACKGROUND: Access blood flow (Qac) is considered a useful indicator in the surveillance of haemodialysis access function. However, changes in Qac may be due to changes in blood pressure and/or to changes in access resistance (AR). METHODS: Weekly readings of Qac, cardiac output, and arterial blood pressure measured early and late during haemodialysis were obtained in 11 patients for a period of 3 weeks. Qac was determined from thermodilution of extracorporeal blood returning to the patient with reversed placement of blood lines and by measurement of arterial and venous blood temperatures in the extracorporeal circulation. Data are given as mean +/- SE. RESULTS: Qac dropped as mean arterial pressure (MAP) and total peripheral resistance (TPR) decreased, but increased when MAP and TPR increased. Linear regressions between the change in access flow and the change in MAP (deltaQac%=0.80*deltaMAP%-1.6, r2=0.39), and the change in TPR (deltaQac%= 0.54*deltaTPR%-9.2, r2=0.35) respectively, were significant (P<0.001). Whereas Qac significantly decreased (-8.4+/-3.3%, P<0.01) during the same treatment, AR remained unchanged (4.7+/-3.2%; P=NS). AR for all studies was 16.5+/-1.0 peripheral resistance units (1 PRU=2.226 kPa min l(-1)). There was a trend for resistance to increase (5.1+/-2.6%, P=NS) and for flow to decrease (-6.1+/-2.3%, P=NS) during the 3 weeks of the study. CONCLUSION: Qac measured during haemodialysis is variable and depends on haemodynamics, but AR is constant. AR is related to the physical structure of the peripheral access. Because of its intradialytic stability AR may be better suited as an indicator of access function.

Blood Pressure↗
PubMed1998

Leadership and governance.

In this chapter, the author discusses leadership and governance issues in implementing curricular reform at the eight schools that participated in The Robert Wood Johnson Foundation's "Preparing Physicians for the Future: Program in Medical Education." Leadership is defined as the roles played by key individuals within a school in facilitating significant curricular change; institutional governance is the administrative structure through which the curricular changes were administered. The characteristics of successful leaders as well as problems caused by poorly chosen leaders are described. The author also discusses how leaders handled resistance to change and the role of students in overcoming this resistance at some institutions. The second half of the chapter focuses on governance structures. The author briefly discusses the role of curriculum committees, how student and faculty committees at some schools worked to implement change, and the implementation at each of the eight schools of a centralized education budget. He concludes with a list of characteristics of successful leadership and successful governance in the process of curriculum reform.

Curriculum↗
PubMed1998

Visualizing nerve cells with VolVis.

VolVis is a high-performance volume visualization software system. It integrates numerous visualization methods within a comprehensive system, providing a flexible tool for the scientist, engineer, and physician, as well as the visualization developer and researcher. Visualizing nerve cells has been a primary application of VolVis, and has served as the driving force behind the development of VolVis. This paper describes VolVis, its unique features, and its various components, as well as several case studies of utilizing VolVis in visualizing nerve cell datasets acquired using confocal microscopy. These studies include visualizing surface structures using both iso-surface and volume rendering, with a specific focus on visualizing calcium.

Animals↗
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

Bike speed measurements in a recreational population: validity of self reported speed.

OBJECTIVE: Speed at the time of a bicycle crash is an important determinant of the amount of energy transmitted. Controlling for speed is thus important in the evaluation of outcomes and effectiveness of intervention strategies. This study was conducted to evaluate the accuracy of self reported speed in a population of recreational cyclists. METHODS: Children's and adults' bicycle speeds were measured with a radar gun as they rode along a closed road at weekend recreational events. Cyclists were then stopped and asked to estimate their speed. Measured speed, cyclist's estimate of their speed, age, and sex were documented. Parents were also asked to estimate their child's speed. RESULTS: One hundred and fifty two cyclists from 4 to 80 years of age participated. Seventy per cent were children 13 years of age or younger. The mean (SD) speed of this group was 8.9 (2.5) mph. Cyclists age 14 and older were traveling at a mean speed of 9.7 (2.87) mph. Estimated speeds were significantly higher than measured speeds for this older group, but there was no significant difference between mean measured and estimated speeds for the younger riders. There was also no significant difference between measured and estimated speed for males and females. Parents estimated their child's speed quite accurately. CONCLUSIONS: Self reported speeds for children were in close agreement with measured speeds and, thus, are sufficiently accurate to be a useful measure of crash severity in evaluating helmet effectiveness.

Adolescent↗
PubMed1996

Acute pancreatitis in an infant with lactic acidosis and a mutation at nucleotide 3243 in the mitochondrial DNA tRNALeu(UUR) gene.

UNLABELLED: The A to G point mutation at position 3243 of the mitochondrial DNA tRNALeu(UUR) gene is commonly found in patients with the syndrome of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS). A male patient was referred at 7 months with failure to thrive, developmental delay, microcephaly and hypotonia since age 2 months. He had developed lactic acidosis and increasingly frequent seizures since age 5 months. The patient was admitted at 15 months with pleural and pericardial effusions, which resolved. Three weeks later he developed evidence of pancreatitis with hyperglycemia, sudden profound increase in lactic acidosis and increased serum lipase. He died unexpectedly the next day of cardiorespiratory collapse following an acute gastro-intestinal hemorrhage. Analysis of mitochondrial DNA (mtDNA) in muscle showed heteroplasmy for the mutation MTTL1*MELAS3243G (> 95%). Infants with this mutation commonly present with failure to thrive, significant developmental delay, and hypotonia, while stroke-like episodes occur later in survivors. They usually have lactic acidosis and a high percentage of mutant mtDNA in muscle. CONCLUSION: Respiratory chain disorders including the mtDNA MTTL1*MELAS3243G mutation should be suspected in infants with this systemic and neurologic presentation. Pancreatic dysfunction, both acute and chronic, needs to be added to the list of symptoms of disorders of the respiratory chain.

Acidosis, Lactic↗
PubMed1996

Insulin resistance associated with maternally inherited diabetes and deafness.

Maternally inherited diabetes and deafness (MIDD) is a form of diabetes associated with mutation of mitochondrial DNA (mtDNA) that occurs in 1% to 2% of individuals with diabetes. Understanding the clinical course and abnormalities in insulin secretion and action in affected individuals should allow better understanding of how this genetic defect alter glucose metabolism. We report the clinical course of three individuals with mtDNA mutations and deafness. Subjects no. 1 and 2 had diabetes not yet requiring insulin therapy, and subject no. 3, the son of subject no. 2, had normal glucose tolerance. Defective oxidative phosphorylation (OXPHOS) based on OXPHOS enzymology of skeletal muscle biopsy of subjects no. 1 and 2 showed activity of less than 5% of the tolerance level in complex III for subject no. 1 and in complexes I, I + III, and IV for subject no. 2. Assessing insulin secretion using insulin response to intravenous glucose and insulin sensitivity based on minimal model analysis of an insulin-modified frequently sampled intravenous glucose tolerance test (FSIGT), first-phase insulin secretion was abnormal in subjects no. 1 and 2 and normal in subject no. 3 (AUC, 57, 93, and 1,235 pmol/L, respectively). In contrast, all three subjects had low insulin sensitivity indices (0.04, 0.14, and 0.27 x 10-4 x min/pmol/L, respectively). Subject no. 2, who underwent three FSIGT studies over a 16-month interval, showed transient improvement in insulin release in response to modification of diet and exercise (first-phase insulin AUC, 57 pmol/min v 287 pmol/min 10 months later; fasting insulin, 97 pmol/L v 237 pmol/L 10 months later), but by 16 months, first-phase insulin release and fasting insulin had decreased (AUC, 64 and 136 pmol/L, respectively) despite higher fasting glucose. We conclude that in our subjects with MIDD, insulin resistance is present and appears to precede defects in insulin release.

Adolescent↗
PubMed1996

Cost-effective endoscopic examination of the contralateral inguinal ring.

OBJECTIVES: Laparoscopic examination of the contralateral inguinal ring has recently been advocated to exclude contralateral hernia in young children. We report a modification using nondisposable cystoscopic equipment, which is quick and reliable. METHODS: Either an 8 or 10 F soft straight catheter or a cystoscope sheath is passed through the open hernia sac. Air is insufflated into the abdomen with a syringe. Once the pneumoperitoneum is completed, a 4-mm cystoscope lens (110 degrees) is used to inspect the contralateral ring. RESULTS: Twenty-four children between the ages of 6 weeks and 4 years (median, 6 months) underwent exploration for presumed unilateral inguinal hernia and laparoscopic examination of the contralateral inguinal ring. Thirteen patients (54%) had an open processus vaginalis and underwent contralateral inguinal herniorrhaphy. No false-positive or false-negative results were found, and there were no complications associated with the procedure. CONCLUSIONS: This method of laparoscopic examination of the contralateral inguinal ring using nondisposable cystoscopic equipment is rapid, safe, reliable, and cost effective in evaluating a contralateral patent processus vaginalis. Laparoscopic examination spares the need for formal surgical exploration in patients with a closed processus vaginalis.

Child, Preschool↗
PubMed1996

Fostering the health of communities: a unifying mission for the University of New Mexico Health Sciences Center.

Fostering the health of communities can serve as a unifying mission of the academic health center (AHC), which can set the AHC apart from other health providers in the community. To achieve this mission, the University of New Mexico's AHC is increasingly focusing education, research, and service upon the identified health and service needs of communities in its state. Since major health problems in our society have social, behavioral, and economic roots, New Mexico's AHC has tapped into the broad expertise of its different components as well as that of its state and community partners to adequately address health problems in the community. Its hospitals offer financing and management resources, its colleges offer innovative approaches to community-based education, and the state department of health offers expertise in health policy development. To adequately respond to the complexity of community health needs, the different colleges and departments at New Mexico's AHC are increasingly merging into integrated governance units. Measures of community outreach success include evidence of strengthened community development, increased health care access, and improved indices of community health. New Mexico's AHC formed an interdisciplinary rural outreach task force, which has demonstrated its ability to form partnerships with state and local agencies and to mobilize institutional resources in education, research, and service from the AHC's different departments, colleges, and hospitals to respond promptly to unique community health needs. Evidence shows that such an integrated, coordinated AHC intervention can generate strong and lasting AHC-community alliances, improve the quality and economic viability of community health systems, and enhance the financial resources of the AHC.

Academic Medical Centers↗