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At least 1,027 records · Page 57Linked to original sources
PubMed2001

Gene expression profile of ARPE-19 during repair of the monolayer.

BACKGROUND: The purpose of this study was to identify the profile of gene expression during retinal pigment epithelial (RPE) wound repair. METHODS: ARPE-19 cells derived from a human RPE cell line were grown for 4 weeks and injured by creating multiple concentric wounds. Unwounded cultures served as controls. During the proliferative phase of wound repair, total RNA was extracted from control and wounded cultures, and a [32P]dATP-labeled cDNA probe was synthesized and hybridized to Atlas Arrays (Clontech, Palo Alto, Calif.) containing 588 cDNAs. The autoradiograms obtained were then analyzed using the Molecular Dynamics software program. Semiquantitative PCR was carried out to confirm up-regulation of four genes associated with wound repair. ELISA was performed to quantitate the secreted MCP-1. RESULTS: In wounded cultures prominent up-regulation (greater than fivefold) was seen for genes encoding DNA synthesis and DNA repair proteins. A greater than threefold increase was seen for genes encoding mitogen-activated protein kinase, CD44, MCP-1 (monocyte chemotactic protein), thymosin beta-10, and HDGF (hepatoma-derived growth factor), among others. Genes encoding tumor suppressors were downregulated three- to five-fold in the wounded compared with the unwounded cultures. Semiquantitative PCR confirmed up-regulation of transcripts for thymosin beta-10, HDGF, CD44, and MCP-1. ELISA showed a 20% increase in secreted MCP-1. CONCLUSIONS: Gene array analysis revealed a differentiation program that included increased expression of genes involved in wound repair (adhesion molecules, cytokines, signal transducers), along with increased MCP-1 secretion. The RPE may be an early participant in the inflammatory response that occurs with proliferative vitreoretinopathy.

Cells, Cultured↗
PubMed1993

Natural frequency/damping coefficient relationship of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure.

Using a digital simulation method, we analyzed the relationship between natural frequency (fn) and damping coefficient (Zeta) of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure. The pulmonary artery pressure waveform was obtained with a catheter-tip transducer and it was fed into a dynamic simulator programmed on a computer. The original waveform and the output of the simulator were compared and judged visually for the fidelity. From this analysis, the combination of fn and Zeta was obtained and was plotted on a fn-Zeta diagram. It showed as an area, which was convex on the left side and open on the right side. The left-convex endpoint was located at a damping coefficient of about 0.7. At a lower heart rate, this area was extended to the lower frequency side, while, at a higher heart rate, this area was limited to the higher frequency side. The fn-Zeta diagram was also constructed theoretically by calculating the relations between natural frequencies and damping coefficients of a second order system with the amplitude and phase error tolerance set at +/-5% respectively.

Journal Article↗
PubMed2006

Simulating fibrin clotting time.

The clotting time (CT) of fibrinogen mixed with thrombin decreased, then increased with increasing fibrinogen levels. By contrast, log CT decreased monotonically with respect to the log level of activating enzyme (thrombin or reptilase). Here, the CT was determined over a large range of fibrinogen concentration (to 100 mg ml(-1)) at a fixed level of enzyme. A new parameter, [Fib]min, the minimal fibrinogen concentration required for thrombin or reptilase-instigated phase change (coagulation), was determined as [Fib]min = 0.2 +/- 0.05 microM fibrinogen. A dynamic simulation program (Stella) was employed to organize simulations based on simple and complex coagulation mechanisms, which generated CT values. The successful simulation aimed at forming [Fib]min and "recognized" the binding of unreacted fibrinogen with intermediate fibrin protofibrils. The "virtual data" mimicked the biphasic experimental CT values over a wide range of concentrations. Fibrinogen appeared to act in three modalities: as a thrombin substrate; as a precursor of fibrin; and as a competitor for fibrin protofibrils. The optimized simulation may provide a basis for predicting CT in more complex systems, such as pathological plasmas or whole blood or at high concentrations encountered with fibrin sealant.

Batroxobin↗
PubMed1990

Effects of exercise testing, training and beta blockade on serum potassium in normal subjects.

To evaluate the effects of exercise testing, training and beta blockade on serum potassium, 40 normal subjects (24 men, 16 women, mean age 33 years) had 4 maximal exercise tests with venipuncture for serum potassium before and less than or equal to 40 seconds after each test. After initial exercise testing, they were randomized to atenolol 50 mg daily, atenolol 100 mg daily, propranolol 80 mg twice daily or placebo. All began a 9-week dynamic exercise program for 8 weeks followed by a 1-week drug-free washout period. Tests were done after weeks 1, 8 and 9. A significant mean increase (p less than 0.05) in serum potassium occurred with maximal exercise in the atenolol 50 mg and propranolol groups after 1 week of treatment (mean +/- standard deviation, 4.78 +/- 0.29 to 5.09 +/- 0.43 mEq/liter and 4.81 +/- 0.55 to 5.30 +/- 0.33 mEq/liter). By week 8 after training, all beta blockade groups showed an increase in postmaximal exercise test serum potassium (atenolol 50 mg, 4.78 +/- 0.29 to 5.11 +/- 0.26 mEq/liter; atenolol 100 mg, 4.95 +/- 0.41 to 5.16 +/- 0.36 mEq/liter; propranolol, 4.81 +/- 0.55 to 5.05 +/- 0.29 mEq/liter). After washout, only the placebo group showed an increase in postmaximal test serum potassium (4.99 +/- 0.46 to 5.35 +/- 0.27 mEq/liter). Data indicate that hyperkalemia with maximal exercise testing increases after training with atenolol and propranolol compared to placebo and that this effect resolves once treatment is discontinued.

Adult↗
PubMed1990

A model for the prospective analysis of perinatal deaths in a perinatal network.

This prospective study assesses factors that contribute to perinatal mortality. The study population includes the 1362 perinatal deaths that occurred among 85,402 live births between 1983 and 1987 at hospitals of the University of Chicago Perinatal Network. After peer review of demographic, clinical, and pathologic data, each perinatal death was classified in one of the following categories: (1) the result of congenital malformation incompatible with life, (2) unavoidable, (3) potentially avoidable by patient, by health provider, or by both, or (4) of undetermined responsibility. Of 1362 deaths, 12.3% involved congenital malformations incompatible with life, 56.9% were classified as unavoidable, 28.1% were judged potentially avoidable, and 2.7% due to undetermined causes. Of potentially avoidable deaths, 36% were due to patient factors (primarily noncompliance), 59% to health provider factors, and 15% to combined patient and provider factors. There was a significant reduction in the potentially avoidable cases during the study period. The maximum attainable reduction in perinatal mortality under optimal conditions is calculated. Intervention plans to achieve this goal are discussed.

Chicago↗
PubMed1986

The ability of women to recall their oral contraceptive histories.

Self-reported contraceptive histories were obtained at interview from 99 women and compared with prospectively collected data from the Oxford-Family Planning Association cohort study. The effect of different memory aids was evaluated and an assessment was made of the completeness and accuracy of contraceptive histories recorded in general practice notes. Accuracy of recall of total duration of use was sufficiently good to establish the presence or otherwise of a duration-response relationship and could be improved by the use of a contraceptive calendar. Recall of specific brands used was less accurate. In studies where accurate information on use of particular preparations is required, the use of a photo album is recommended, supplemented by data obtained from general practice records to improve the accuracy of dates. General practice records on their own are not sufficiently complete to be used as a sole source of exposure data in studies in which it is important to obtain a complete oral contraceptive history.

Adult↗
PubMed1992

Agreement between oral contraceptive users and prescribers: implications for case-control studies.

Case-control studies examining the effects of oral contraceptives (OC) are prone to misclassification bias due to errors in assessment of OC use. Concern about inaccurate exposure histories has increased since current studies require women to recall OC use over prolonged periods of time. In preparation for a case-control study of breast cancer and OC use, an investigation was carried out to assess agreement between women's lifetime histories of OC use (covering a period of up to 20 years) and prescribers' records. OC histories were obtained during personal interview with 218 women who had used OC at some point in their lives (127 breast cancer patients, 91 controls). Recall was aided by an album with color photographs of all OC marketed in the Netherlands from 1962 onwards (n = 65), and a calendar that covered the women's life span from date of birth to menopause. The participants were asked for the names of all physicians who prescribed OC for them. The rate of response from the prescribers was high (94%), but only half of the forms provided useful information. Patient-prescriber agreement on brand names (including dosage) was 70%. About half of the women agreed with their prescribers on starting dates to within less than a year's difference. Approximately the same percentage of agreement was found for stopping dates. Multiple linear regression indicated that agreement on brand names and dates of usage was lower for women of low socioeconomic status, for healthy women (as compared to breast cancer patients) and for periods of pill use that had to be recalled from the more distant past. Agreement on total duration of use was high enough to permit testing of a moderately strong duration-response relationship in a case-control study.

Adult↗
PubMed1992

Impact of user fees on attendance at a referral centre for sexually transmitted diseases in Kenya.

We investigated the impact of a short-lived policy of charging fees to patients attending public-sector outpatient health facilities in Kenya by collecting data on attendance at Nairobi's Special Treatment Clinic for sexually transmitted diseases (STDs) before (23 months), during (9 months), and after (15 months) the user-charge period. During the user-charge period, the seasonally adjusted total mean monthly attendance of men decreased significantly to 40% (95% CI 36-45) of that before fees were levied. Attendance rose in the post-user-charge period, but reached only 64% (59-68) of the pre-user-charge level. For women, the adjusted total mean monthly attendance during the user-charge period was reduced significantly to 65% (55-77) of the pre-user-charge level. Mean monthly attendance by women rose in the post-user-charge period to 22% (9-37) above the pre-user-charge level. There was no evidence of an increase in attendance over the course of the user-charge period among either men or women. The introduction of user fees probably increased the number of untreated STDs in the population, with potentially serious long-term health implications. The user-fee experience in Kenya should be carefully evaluated before similar measures are introduced elsewhere.

Community Health Centers↗
PubMed1996

Conceptions and misconceptions. Decisions about pregnancy.

Induced abortion has been practiced in every known society and in every era of history. Psychological concomitants of abortion are as much a product of the social and interpersonal context as of the process itself. Though abortion results in the loss of a potential human life, it is not associated with significant psychiatric morbidity, and, in fact, represents for many women--and men--a significant milestone in which they assume responsibility for the direction of their lives for the first time. However, assertions that abortion is psychologically damaging have characterized much of the recent bitter debate over the legality and availability of abortion. It is important that mental health professionals are knowledgeable about the subject of abortion so that they can discuss policy with their patients.

Abortion, Induced↗
PubMed1984

Correlates of urban mortality: a social area analysis.

A method of social area analysis developed by Shevky and Bell is used to analyze mortality among the census tracts of Des Moines, Iowa. "Social rank, urbanization, and segregation indices as well as age-standardized death rates were calculated for each census tract. All variables were treated as continuous, and correlation and regression procedures were used to analyze the data. The findings were consistent with those of previous studies and all relationships were as expected. Regression analysis revealed that segregation contributed little to the explanation of variation in age-standardized death rates, suggesting that segregation is not an important determinant of life styles affecting mortality independent of social rank. The results were interpreted in terms of social class differences in accessibility to medical assistance and assumption of the sick role."

Americas↗
PubMed1989

The clinical advantages of I-125 seeds as a substitute for Ir-192 seeds in temporary plastic tube implants.

In August of 1986 at William Beaumont Hospital, Iodine-125 (I-125) seeds were introduced in the clinical practice as a substitute for Iridium-192 (Ir-192) seeds in patients undergoing temporary plastic tube interstitial implants. Through February 1988, 108 I-125 implants were performed in 105 patients. Acute and chronic toxicity was indistinguishable from Ir-192. However, improved radiation safety and a dynamic dosimetric program have resulted from this endeavor. Because of the multiple clinical advantages of I-125, we feel that this should be considered the isotope of choice in temporary interstitial plastic tube implants.

Brachytherapy↗
PubMed1989

Early dynamic splinting for extensor tendon injuries.

Extensor tendon injuries are traditionally splinted with no motion for 3 to 4 weeks after repair. This may result in limitation of flexion because of extensor tenodesis at the site of repair. To prevent this, we used a dynamic splinting program opposite to the one that is used for flexor tendon repair, with an outrigger splint holding the fingers in extension and allowing full active flexion. Fifty-two patients who had extensor tendon repairs in the area from the wrist to the middle of the proximal phalanx were treated. Motion was begun 2 to 5 days after repair and was continued for approximately 5 weeks. No tendon ruptures occurred, and all patients recovered full flexion.

Adult↗
PubMed1993

Photon beam compensation design: dose optimization in 3D volume for parallel opposed beams.

Most existing methods for photon beam compensation design is based on the dose optimization in a 2D plane through the treatment volume for each individual beam. These approaches do not, however, optimize the dose uniformity in the dimension along the beam path (hence not in the 3D volume). In this work, the author presents a practical compensation design algorithm for 3D dose optimization. In contrast to existing methods, the present algorithm simultaneously calculates the desired cross-beam transmission factor map of the compensation device for each pair of parallel opposed beams. By using computed tomography scans, the patient's external shape and the internal inhomogeneous tissue density are also taken into account. The result is used to construct beam-attenuating compensators or to program a dynamic beam delivery scheme. The algorithm is presented in a form easily adaptable to different dose calculation systems. Compared to other methods, superior dose uniformity is achieved via the present approach.

Humans↗
PubMed2004

The fluorescence studies of the sol-gel transition by styrylpyridine derivative.

The gelation process of tetraethylorthosilanes in acid environment was monitored with the trans-4-(p-N,N-dimethylaminostyryl)-N-vinylbenzylopyridinium chloride (vbDMASP) fluorescent probe. The fluorescence steady-state and anisotropy measurements of material during sol-gel transition are reported. The results are compared with fluorescence studies of the probe in a modeled viscous system of water-glycerol mixtures. A strong increase of anisotropy, from 0.1 to 0.9, with gelation time as well with wavelength, was observed. Although the increase of anisotropy with wavelength is due to specificity of the compounds exhibiting charge transfer properties, the increase of the anisotropy with gelation time is due to an increase of microviscosity. On this basis, suitability of the applied fluorophore in recording of viscosity changes during sol-gel transition is discussed. The molecular structure of vbDMASP in the excited states in dependence on environmental polarity was optimized using the HyperChem and Amsol program. The dynamics of torsional angle C35-C34-N31-C28 of the multichromophore dye in correlation with micropolarity and microviscosity of the network formation during the sol-gel transition is discussed.

Aniline Compounds↗
PubMed2007

Recruitment.

Child and adolescent psychiatry has long been recognized as a shortage specialty by various national studies. The workforce has never increased to the extent that meets society's demand, however. The workforce crisis has continued with declining funding for residency, declining clinical revenues, and declining recruitment of trainees. This article reviews the historical trend of recruitment, recruitment dynamics (training programs and trainees), workforce models, and future direction. It concludes with hope and excitement in the field for recruitment, including the American Academy of Child and Adolescent Psychiatry's 10-year recruitment initiative that has been generating the support of medical/psychiatric educators, governmental agencies, and the public at large, to improve the profession's recruitment efforts to provide access to quality care and needed services to the nation's children and adolescents and their families.

Adolescent↗