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Biomedical subjects

A Kaufman

Publications and source records attributed to A Kaufman.

At least 19 recordsLinked to original sources
PubMed2004

Flint mining in prehistory recorded by in situ-produced cosmogenic 10Be.

The development of mining to acquire the best raw materials for producing stone tools represents a breakthrough in human technological and intellectual development. We present a new approach to studying the history of flint mining, using in situ-produced cosmogenic 10Be concentrations. We show that the raw material used to manufacture flint artifacts approximately 300,000 years old from Qesem Cave (Israel) was most likely surface-collected or obtained from shallow quarries, whereas artifacts of the same period from Tabun Cave (Israel) were made of flint originating from layers 2 or more meters deep, possibly mined or quarried by humans.

Journal Article↗
PubMed2002

Immunoreactivity of p53, Ki-67, and c-erbB-2 in phyllodes tumors of the breast in correlation with clinical and morphologic features.

BACKGROUND AND OBJECTIVES: Phyllodes tumor (PT) is a biphasic tumor with unpredictable behavior. Our study aimed to evaluate clinicopathologic factors and biomarkers that may be helpful in predicting the outcome of these tumors. METHODS: We evaluated immunoreactivity of p53, c-erbB-2, and Ki-67 in 23 PT treated over a 10-year period. The proliferative activity in PT and expression of p53 and c-erbB-2 were correlated with clinicopathologic features of the tumors and patients' outcome. RESULTS: Positive stromal p53 immunoreactivity was found in PT with atypia, infiltrative borders, high cellularity, as well as in PT that displayed higher then average proliferation index, although none of these parameters reached statistical significance. There was a good correlation between proliferative stromal cell activity expressed Ki-67-labeling index and the malignant features of the tumors. Primary tumors that recurred displayed high proliferative activity. Three of four recurrent tumors showed a progression toward higher malignant phenotype with concomitant increase in proliferative stromal cell activity. c-erbB-2-positive tumors had no particular histologic features or association with either p53 positivity or higher proliferative indices. CONCLUSIONS: p53 expression tends to be more frequent in PT with higher malignant potential but did not predict recurrence. Incompletely excised tumors that recurred displayed high proliferative activity in their primary tumors. Progression toward more malignant phenotype in the recurrent PT was accompanied with increase in stromal cell proliferative activity, suggesting the presence of biological continuity between benign, borderline, and malignant PT.

Adolescent↗
PubMed2002

Bone marrow transplantation for paediatric AML in first remission: a systematic review and meta-analysis.

For children with AML in CR1, the major consolidation therapies are BMT, ABMT and intensive chemotherapy. The relative effectiveness of these strategies is still debated. We conducted a systematic review and meta-analysis of trials to determine the effectiveness of BMT and ABMT in CR1 in paediatric AML. Eligible studies enrolled patients <21 years from 1985 to 2000 with AML in CR1. Two groups of studies were identified: (1) Those comparing the outcome of patients with and without a histocompatible family donor; and (2) Randomised controlled trials (RCT) comparing ABMT with non-myeloablative chemotherapy. The relative risk statistic was calculated for outcomes of interest in each trial. If there was no excessive heterogeneity between trials the results were pooled, and an overall relative risk and risk difference for treatment effect across trials were calculated. Results of the analysis showed that allocation to BMT reduced risk of relapse and improved disease-free and overall survival. For ABMT, heterogeneity of effect between RCTs prevented pooling of results. In conclusion, BMT from a histocompatible family donor improves patient outcome. Data are insufficient to determine whether this is true for all subgroups of AML, and whether ABMT is superior to non-myeloablative chemotherapy. An individual patient data meta-analysis is required to further evaluate the available data.

Adolescent↗
PubMed2001

Chemistry of ion coordination and hydration revealed by a K+ channel-Fab complex at 2.0 A resolution.

Ion transport proteins must remove an ion's hydration shell to coordinate the ion selectively on the basis of its size and charge. To discover how the K+ channel solves this fundamental aspect of ion conduction, we solved the structure of the KcsA K+ channel in complex with a monoclonal Fab antibody fragment at 2.0 A resolution. Here we show how the K+ channel displaces water molecules around an ion at its extracellular entryway, and how it holds a K+ ion in a square antiprism of water molecules in a cavity near its intracellular entryway. Carbonyl oxygen atoms within the selectivity filter form a very similar square antiprism around each K+ binding site, as if to mimic the waters of hydration. The selectivity filter changes its ion coordination structure in low K+ solutions. This structural change is crucial to the operation of the selectivity filter in the cellular context, where the K+ ion concentration near the selectivity filter varies in response to channel gating.

Animals↗
PubMed2001

Lead concentrations and isotopic ratios in the sediments of the Sea of Galilee.

The isotopic composition and concentrations of Pb in the sediments of the Sea of Galilee (Lake Kinneret) were measured. The studied sediments have been deposited in the lake since the early 1900s (ca. 1920), hence Pb data record the transition from a period when the lake vicinity was sparsely populated to the present (approximately 100,000 people living in the area around the lake). In general, there is either a constant or a relatively slow increase in Pb concentrations from 40 cm depth (3.5-4.4 microg/g; ca. 1920) to 17 +/- 2 cm below the sediment-water interface (3.7-7.2 microg/g;), which was deposited in the mid-1960s. From 17 +/- 2 cm below the surface, there is a much faster increase up to 7 +/- 2 cm below the surface (from 6.5 to 11.5 microg/g; 1982-1983), and from 7 +/- 2 cm there is a gradual decrease in Pb concentrations toward the sediment-water interface. At station G, near the outlet of the Jordan River, Pb concentrations drop between 29 and 25 cm below the surface, probably reflecting changes in the particulate load of the Jordan River due to the drying out of the Hula Swamp in the early 1950s. 206Pb/207Pb values in all the stations record most of the shifts displayed by Pb concentrations in the sediment. The estimated value of total Pb deposited annually in the lake sediment in the early 1990s is very close to the value obtained from measurements of Pb fluxes to the lake from eolian and fluvial sources. On the basis of the linear relationship between 206Pb/207Pb (or 208Pb/207Pb) and 1/[Pb], we argue that two end-members contribute most of the Pb to the lake sediments. Sources of Pb to the lake include (i) the weathering of basalt from the eastern Galilee and the Golan Heights contributing 2.6 +/- 0.5 microg/g Pb to the sediment and (ii) anthropogenic Pb that is affecting both surface and deep (from 30 to 40 cm) lake sediments. At station S, a third source, Pb released from soils developed on carbonates, should be considered as well.

Isotopes↗
PubMed2001

Successful surgical rehabilitation of children with traumatic corneal laceration and cataract.

OBJECTIVE: To evaluate the visual and refractive outcome of corneal transplant surgery, cataract extraction, and intraocular lens (IOL) implantation in children with traumatic corneal laceration and cataract. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Five patients, 7 years of age or younger, who underwent penetrating keratoplasty, cataract extraction, and IOL implantation for traumatic corneal laceration and cataract were identified. MAIN OUTCOME MEASURES: Each case was analyzed retrospectively for the following factors: preoperative findings; surgical technique, including management of the posterior capsule; measurement of axial length and keratometry; calculation of IOL power, style, and type of IOL implanted; graft clarity; final visual acuity; and final refraction. RESULTS: The five children ranged from 3 to 7 years of age at the time of trauma. All had primary repair of their injury before referral. Each patient was observed for more than 2 years. Each had a posterior chamber IOL placed in the sulcus. After surgery, no severe complications were observed. The preoperative visual acuity ranged from 20/400 to light perception. After surgery, all five patients had clear grafts and an improved visual acuity ranging from 20/20 to 20/400. The final spherical refraction in each patient was within 3.75 diopters (D) of plano, with 1.50 to 3.25 D of cylinder. CONCLUSIONS: Successful surgical rehabilitation was accomplished in these patients. Despite their young age and the difficulty in determining IOL power, combining surgery and aggressive amblyopia therapy resulted in visual rehabilitation with refractions approaching emmetropia.

Cataract↗
PubMed2000

Managed care for uninsured patients at an academic health center: a case study.

In 1997, the University of New Mexico Health Sciences Center ("the Center") created a managed care plan ("the Plan") for its uninsured patients who were county residents. The Plan's features include pooling the resources of existing county safety-net providers, enrolling patients with primary care providers at easily accessible neighborhood-based clinics, and investing in social support services, case management, and 24-hour telephone triage. After two years of the Plan's operation, the utilization of ambulatory care services by Plan enrollees, the number of discharges per 1,000 enrollees from the Center-affiliated University Hospital, and the number of hospital days per 1,000 enrollees had all dropped significantly (p < .001 for all). For the 13,114 enrollees in the Plan, University Hospital saved an estimated $1,904,872 per year in costs. The replacement of unpaid hospital days with paying patients is estimated to have yielded over $695,000 in additional revenues per year. The authors conclude that managing the care of uninsured patients in an academic health center can reduce ambulatory care and inpatient utilization and reduce the cost of care. To achieve these favorable outcomes requires the organization of services to meet the unique needs of the uninsured and underserved population.

Academic Medical Centers↗
PubMed2000

Microfat grafting: the nurse's role.

Fat tissue is a complex and delicate structure that is easily damaged by mechanical and chemical insults. Structural microfat grafting involves the atraumatic harvest, cleansing, preparation, separation, and transplantation of small numbers of fat cells. The microfat grafting technique has been shown to successfully correct contour problems without resorption of the fat cells. Early work with fat transplantation, when the fat was injected subcutaneously or transplanted in bulk, was disappointing with significant loss of volume from central fat necrosis. Recent refinements in fat transplantation advocate the use of 1 to 2 mm threads of fat. This technique has been shown to improve contour problems or augment normal facial anatomy without resorption of the fat cells.

Adipose Tissue↗
PubMed1999

Psychotropic medication treatment patterns among school-aged children in foster care.

This study describes the level of psychotropic medication use and patterns of such treatment among school-aged children in foster care. Structured survey interviews were conducted in the foster homes of 302 randomly selected children, aged 6-12 years, who were living in foster care for 6 months or more and placed from three county service areas. Follow-up mental health assessments using the existing system of care format were completed on 255 children. Sixteen percent of these school-aged children in foster care were found to have taken psychotropic medication during their lifetime. The most common class of medication used in the past year was stimulants (62%). Children who were older, from Caucasian and biracial backgrounds, and who lived in a group home more likely to have taken psychotropic medication in the past year. Among those children who received a clinician diagnosis of a severe psychiatric disorder for which medication is an accepted component of care, boys were more likely to receive medication treatment than girls. Sociodemographic characteristics and placement history variables may be influential in the level of psychotropic medication use among this population. Further research to examine the appropriateness and level of benefit of medication treatment in this population is needed.

Attention Deficit Disorder with Hyperactivity↗
PubMed1999

Interdisciplinary ambulatory education and service in primary care at the University of New Mexico.

To compete and survive in a managed care market, academic health centers must develop integrated delivery systems in general and an integrated primary care system in particular. However, the departmental-based structure at most academic health centers is ill-suited to this purpose. Service and education are usually segregated by department, and the professional activities of primary care faculty in different departments are fragmented, leaving them weakened as a political force within the institution. The University of New Mexico established a model of integrated primary care education and service by creating three interdisciplinary primary care clinics staffed by primary care residents and faculty. The clinics attracted a substantial portion of each department's faculty and residents. The clinics united primary care providers from different departments as a stronger, more unified voice in negotiating with the hospital and in fostering needed changes for primary care in the institution. Interdisciplinary teams require considerable time and labor both in planning (because of joint decision making) and in operation. Better staff structures and staff development must be learned through trial and error because there are not established benchmarks for interdisciplinary teams. Governance presents problems, primarily because loyalties to departments may supersede those to the clinic practice, and sometimes the departments' teaching priorities are challenged by clinic directors' need to ensure filling their interdisciplinary staff needs. These obstacles to collaboration can be addressed creatively, and ultimately the comprehensiveness and quality of care convinces providers and the institution.

Academic Medical Centers↗
PubMed1999

Measuring social responsiveness of medical schools: a case study from New Mexico.

Medical schools can assess their social responsiveness by gauging the degrees to which the health needs of the populations and communities they serve frame their missions and endeavors in education, service, and research. Beyond considering these traditional academic missions, medical schools can also assess how well they apply their expertise to needed reform of the health care delivery system and to the formation of health policies aimed at improving community health status. This article summarizes the means by which a medical school's social responsiveness can be judged in each of the above areas, and it presents examples of successes and failures in such responsiveness by the University of New Mexico School of Medicine. It concludes with lessons learned that can guide future innovations in social responsiveness of medical schools.

Curriculum↗
PubMed1999

Decreased superoxide production, degranulation, tumor necrosis factor alpha secretion, and CD11b/CD18 receptor expression by adherent monocytes from preterm infants.

Preterm infants have an increased incidence of infection, which is principally due to deficiencies in neonatal host defense mechanisms. Monocyte adherence is important in localizing cells at sites of infection and is associated with enhanced antimicrobial functions. We isolated cord blood monocytes from preterm and full-term infants to study their adhesion and immune functions, including superoxide (O2-) generation, degranulation, and cytokine secretion and their adhesion receptors. O2- production and degranulation were significantly diminished, by 28 and 37%, respectively, in adherent monocytes from preterm infants compared to full-term infants (P < 0. 05); however, these differences were not seen in freshly isolated cells. We also observed a significant decrease of 35% in tumor necrosis factor alpha secretion by lipopolysaccharide-stimulated adherent monocytes from preterm infants compared to full-term infants (P < 0.05); however, this difference was not observed in interleukin-1beta or interleukin-6 production by the monocytes. The cell surface expression of the CD11b/CD18 adhesion receptor subunits was significantly decreased (by 60 and 52%, respectively) in monocytes from preterm infants compared to full-term infants (P < 0. 01). The cascade of the immune response to infection involves monocyte upregulation and adherence via CD11b/CD18 receptors followed by cell activation and the release of cytokines and bactericidal products. We speculate that monocyte adherence factors may be important in the modulation of immune responses in preterm infants.

Birth Weight↗
PubMed1999

Psychotropic medication use among children in foster care: relationship to severe psychiatric disorders.

OBJECTIVES: This study sought to describe the level of psychotropic medication use and its relationship to severe psychiatric disorders among school-aged children in foster care. METHODS: Home interviews with 302 foster parents and children aged 6 to 12 years and 266 follow-up clinical evaluations were conducted. RESULTS: Thirteen percent of the children had taken psychotropic medication in the previous year, and 52% of those whose clinical status merited a medication evaluation had not received medication in the previous year. CONCLUSIONS: As the efficacy of psychotropic medication treatment for severe child psychiatric disorders becomes more established, research on the appropriateness of such care can begin.

Child↗