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Donovan FM, Taylor BC. Enhanced cardiac thermal dilution analysis for cardiac output, volumes, stroke volumes, and regurgitation rates--sensitivity analysis using digital simulation. Crit Rev Biomed Eng 2001; 28:69-74. [PMID: 10999367 DOI: 10.1615/critrevbiomedeng.v28.i12.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Cardiac output is measured by placing a double lumen catheter with a thermistor on the tip through the right ventricle into the pulmonary artery, injecting cold saline into the right atrium, and integrating the resulting pulmonary artery temperature profile. If a similar procedure is performed with thermistors located in the right atrium, right ventricle, and pulmonary artery, the resulting temperature curves are determined by the known or easily measured quantities: injectate temperature, injectate volume, heart rate, systolic time interval, body temperature, and time in the cardiac cycle at which injection begins and the unknown quantities: right atrial, right ventricular, pulmonary artery mean and stroke volumes, inflow and outflow valve regurgitation rates, and cardiac output. A digital computer program using a lumped parameter model has been developed to use these quantities to produce thermal dilution curves and optimize the fit of the model curves to the temperature curves from the thermal dilution measurement to determine the unknown quantities. The program is used to investigate the effects of measuring system time constant, heat transfer, and noise on the accuracy of these measurements. The results indicate that the method is practical.
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McBride JW, Corstvet RE, Taylor BC, Osburn BI. Primary and anamnestic responses of bovine bronchoalveolar and peripheral blood lymphocyte subsets to aerosolized Pasteurella haemolytica A1. Vet Immunol Immunopathol 1999; 67:161-70. [PMID: 10077422 DOI: 10.1016/s0165-2427(98)00218-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Site-specific responses of bronchoalveolar and peripheral blood lymphocyte subsets were compared during primary and anamnestic immune responses against live Pasteurella haemolytica A1 (Ph1). Eight 1-year old calves were sequentially exposed intrabronchially with aerosolized Ph1 on days 0, 14, and 21, and two calves were sham exposed. Bronchoalveolar and peripheral blood lymphocytes were analyzed before each Ph1 exposure, and on days 3 and 7 post exposure using single and two-color flow cytometry to identify CD2+, CD4+, CD8+, CD21+, CD45R+, CD25+ and gammadelta lymphocyte subsets. Significant differences (p < 0.05) in bronchoalveolar and peripheral blood lymphocyte subsets were observed before Ph1 exposure. Subsequent aerosol exposures, resulted in significant (p < 0.05) changes in bronchoalveolar lymphocyte subsets and the CD4:CD8 bronchoalveolar lymphocyte ratio, but concomitant changes were not observed in peripheral blood lymphocytes. Expression of CD2, CD4 and CD8 lymphocyte differentiation antigens was consistently lower and more heterogeneous on bronchoalveolar lymphocytes. Differential analysis of bronchoalveolar leukocytes revealed a significant increase in bronchoalveolar lymphocytes and neutrophils during anamnestic responses.
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Mulavara AP, Timmons WD, Nair MS, Gupta V, Kumar AA, Taylor BC. Electrical impedance cardiography using artificial neural networks. Ann Biomed Eng 1998; 26:577-83. [PMID: 9662150 DOI: 10.1114/1.47] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This study evaluates the use of artificial neural networks to estimate stroke volume from pre-processed, thoracic impedance plethysmograph signals from 20 healthy subjects. Standard back-propagation was used to train the networks, with Doppler stroke volume estimates as the desired output. The trained networks were then compared to two classical biophysical approaches. The coefficient of determination (R2 x 100%) between the biophysical approaches and the Doppler was 8.20% and 9.90%, while it was 77.38% between the best neural network and the Doppler. Among these methods, only the neural network residuals had a significant zero mean Gaussian distribution (alpha=0.05). Our results indicate that an invertible relationship may exist between thoracic bioimpedance and stroke volume, and that artificial neural networks may offer a potentially advantageous approach for estimating stroke volume from thoracic electrical impedance, both because of their ease of use and their lack of confounding assumptions.
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Taylor BC, Keefe RG, Dellinger JD, Nakamura Y, Cullor JS, Stott JL. T cell populations and cytokine expression in milk derived from normal and bacteria-infected bovine mammary glands. Cell Immunol 1997; 182:68-76. [PMID: 9427811 DOI: 10.1006/cimm.1997.1215] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This study investigated the effect of naturally acquired bacterial infection of the bovine mammary gland on subpopulations of T lymphocytes and cytokine expression in milk. Twenty-nine lactating cows with mastitis were compared to 12 normal animals. CD4+ lymphocytes represented a significantly greater percentage of the milk-derived lymphocytes in infected mammary glands compared to normal controls. Cytokine mRNA expression by cells derived from milk was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR). No IL-2 or IL-4 mRNA was detected in any samples, while IFN-gamma mRNA was detected in all milk samples. IL-10 mRNA was detected in cells from the milk of 2 mastitic cows and 1 normal cow, and IL-12 mRNA was detected in 2 cows with mastitis. While TNF-alpha mRNA was not detected in this study, IL-6 mRNA was identified in cells from the milk of all animals, with levels being greater in mastitic animals.
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McBride JW, Corstvet RE, Dietrich MA, Berry C, Brennan R, Taylor BC, Stott JL, Osburn BI. Memory and CD8+ are the predominant bovine bronchoalveolar lymphocyte phenotypes. Vet Immunol Immunopathol 1997; 58:55-62. [PMID: 9343339 DOI: 10.1016/s0165-2427(96)05777-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bovine lymphocytes obtained by bronchoalveolar lavage (BAL) of healthy calves were simultaneously analyzed and compared to peripheral blood lymphocytes using monoclonal antibodies specific for bovine leukocyte differentiation antigens. Phenotypic differences were observed between bronchoalveolar and peripheral blood T-lymphocyte subpopulations, demonstrating selective lymphocyte migration to the bovine lung. The bronchoalveolar and peripheral blood T-lymphocyte populations, defined by expression of CD2, were similar, but bronchoalveolar T lymphocytes were predominately CD8+ while peripheral blood T cells were predominately CD4+. In addition, memory lymphocytes, characterized by low expression of CD45R and activated lymphocytes (CD25+), were found in significantly higher proportions in the bronchoalveolar compartment. The proportion of gammadelta T lymphocytes was, however, significantly higher in peripheral blood. B cells were observed in similar proportions in the bronchoalveolar compartment and peripheral blood.
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Meyers PJ, Bowman T, Blodgett G, Conboy HS, Gimenez T, Reid MP, Taylor BC, Thayer J, Jöchle W, Trigg TE. Use of the GnRH analogue, deslorelin acetate, in a slow-release implant to accelerate ovulation in oestrous mares. Vet Rec 1997; 140:249-52. [PMID: 9080642 DOI: 10.1136/vr.140.10.249] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In two separate controlled clinical trials, the efficacy and safety of 2.2 mg of the GnRH analogue deslorelin, administered subcutaneously as a short-term implant to normally cycling mares in oestrus with a dominant ovarian follicle more than 30 mm in diameter, were evaluated, using a placebo as a negative control. The oestrous cycle of each mare was followed by teasing, palpation per rectum and transrectal ultrasonography. Follicles were monitored every 24 hours by ultrasonography until ovulation occurred. The mares were either mated naturally or inseminated artificially. In trial 1, 174 mares were treated at six locations in Canada, and in trial 2, 98 mares were treated at three locations in the USA. In trial 1, the treatment with deslorelin reduced the mean (sd) time to ovulation from 84.2 (48.4) hours to 50.2 (19.6) hours (P < 0.001) and in trial 2 it reduced it from 88.8 (40.3) hours to 54.1 (26.5) hours (P < 0.001). In trial 1, the percentage of mares ovulating within 48 hours increased from 37.7 per cent in control mares to 86.1 per cent in treated mares (P < 0.001) and in trial 2 the percentage increased from 26.5 to 80.9 per cent (P < 0.001). In trial 2, the duration of oestrus in the deslorelin-treated mares was reduced from 6.1 days to 4.3 days and the number of matings or artificial inseminations was reduced from 2.5 to 1.7 (P < 0.001). In trial 1, days 12 to 20 pregnancy rates for matings at the treatment oestrus were not different for deslorelin-treated (75.6 per cent) and placebo-treated (66.1 per cent) mares. In trial 2, days 12 to 20 pregnancy rates from matings at the treatment oestrus were lower for deslorelin-treated (58.7 per cent) than for placebo-treated (83.3 per cent) mares (P < 0.05), although pregnancy rates were similar for deslorelin-treated (97.1 per cent) and placebo-treated (95.0 per cent) mares after mating at the second oestrus. In both trials, pregnancy losses due to early or late abortions were within the normally expected range and similar for deslorelin-treated (3.6 and 3.7 per cent, respectively) and placebo-treated (13.4 and 7.5 per cent) mares. The treatments did not cause systemic side effects and local reactions at the implantation sites were slight and of short duration.
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Barratt-Boyes SM, Rossitto PV, Taylor BC, Ellis JA, MacLachlan NJ. Response of the regional lymph node to bluetongue virus infection in calves. Vet Immunol Immunopathol 1995; 45:73-84. [PMID: 7604539 DOI: 10.1016/0165-2427(94)05331-l] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Bluetongue virus (BTV) infection of cattle is characterized by prolonged cell-associated viremia. In an effort to further evaluate the antiviral response of BTV-infected cattle, the role of the regional lymph node (LN) in the immune response of calves to BTV was characterized. Calves were inoculated with BTV in the skin of the neck in an area drained by the superficial cervical LN. Calves were euthanized at regular intervals after inoculation and both BTV-challenged and contralateral (control) superficial cervical LNs were harvested. In addition, some calves had cannulation of the superficial cervical efferent lymphatics prior to inoculation. Lymphocyte subpopulation analysis was done on LN cell suspensions and lymph cells using a panel of cell-specific monoclonal antibodies. There was a significant increase in the proportion of B cells in the challenged LN after inoculation as compared with the control LN. In addition, BTV-specific antibodies were detected in efferent lymph plasma from the challenged LN in one cannulated calf by 9 days after inoculation (DAI), as determined by competitive enzyme-linked immunosorbent assay, whereas BTV-specific antibodies were not detected in serum from this calf through 12 DAI. Analysis of lymph cells revealed a sustained increase in cell output from the challenged LN due to an increase in lymphoblasts and CD8+ T cells. In contrast, the cell output from the control LN dropped markedly by 8 DAI and there was no significant increase in any specific cell population. Double label analysis characterized lymphoblasts as activated CD8+ cells, as determined by expression of MHC Class II antigens (CD8+ MHC II+). These cells were only transiently present as CD8+ MHC II+ cells were not identified in lymph from the challenged LN at 14 DAI. Few CD8+ MHC II+ cells were identified at any time in lymph from the control LN or in lymph from a mock infected calf. The data indicate that B cell proliferation in the challenged LN and release of activated CD8+ cells from this LN were specific responses to BTV infection. The rapid expansion of activated CD8+ T cells indicates that these cells may limit early viral spread. It is concluded that the regional LN draining inoculated skin is critical to the immune response of calves to BTV infection.
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Taylor BC, Mattapallil J, Moore PF, Scibienski RJ, Stott JL. Characterization of a novel bovine leukocyte protein involved in cell-cell adhesion. TISSUE ANTIGENS 1994; 44:252-60. [PMID: 7532875 DOI: 10.1111/j.1399-0039.1994.tb02391.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Preliminary characterization of an apparently novel bovine leukocyte adhesion protein is described. Two IgG1 monoclonal antibodies, UC-C1 and UC-H5, raised against established cultures of IL-2-dependent bovine peripheral blood lymphocytes (PBL) were found to react with an antigen expressed by the majority of bovine peripheral blood leukocytes. Immunoprecipitation and polyacrylamide gel electrophoresis of the antigen produced a distinct protein band of molecular weight 160,000, and additional diffuse protein bands of approximate molecular weight 180,000, 175,000, and 150,000. Two-color flow cytometric analyses showed that the antigen was expressed at low density on a small proportion of circulating B lymphocytes, but was highly expressed on all circulating T lymphocytes. The majority of monocytes and all granulocytes expressed the antigen at a density lower than that of T lymphocytes. Peripheral blood lymphocytes stimulated with concanavalin A had an approximately 3-fold increased expression of the antigen, which was apparent within 18 h and remained stable in long-term cultures. Expression of the antigen in thymus, analyzed by the immunoperoxidase technique, was predominantly restricted to thymocytes in the immediate subcapsular cortex and medulla; expression in lymph nodes and spleen was predominantly confined to lymphocytes in T-cell areas. Flow-cytometric analysis demonstrated that thymocytes and the majority of peripheral and mesenteric lymph node-derived T cells had relatively low surface density of antigen compared to circulating T cells. Binding of UC-C1 or UC-H5 to the antigen on lymphocytes induced homotypic aggregation. UC-C1 completely blocked binding of FITC-conjugated UC-H5 to blood mononuclear cells, suggesting that the antibodies recognize the same epitope or proximal epitopes.
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Taylor BC, Dellinger JD, Cullor JS, Stott JL. Bovine milk lymphocytes display the phenotype of memory T cells and are predominantly CD8+. Cell Immunol 1994; 156:245-53. [PMID: 8200039 DOI: 10.1006/cimm.1994.1169] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The phenotype of bovine milk lymphocytes was investigated and compared to peripheral blood lymphocytes using monoclonal antibodies specific for bovine leukocyte differentiation antigens and flow cytometry. T lymphocytes traffic selectively into bovine milk while B lymphocytes represent a minor population in milk by comparison to peripheral blood. The vast majority of T cells in milk express alpha beta T cell receptors and are predominantly CD8+. T cells in milk express twofold higher levels of CD2 and fivefold lower levels of CD45R, characteristics associated with memory T cells. Grouping of cows by lactational stage and analysis of lymphocyte subpopulation percentages indicated that CD4+ T cells are present in relatively low numbers in milk of cows in the first 50 days of lactation and have a significant tendency to increase in number as lactation progresses.
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Taylor BC, Choi KY, Scibienski RJ, Moore PF, Stott JL. Differential expression of bovine MHC class II antigens identified by monoclonal antibodies. J Leukoc Biol 1993; 53:479-89. [PMID: 7684762 DOI: 10.1002/jlb.53.5.479] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Four monoclonal antibodies (mAbs), UC-A4, UC-D3, UC-H9, and IL-A21, specific for bovine major histocompatibility complex class II proteins are described. Sequential immunoprecipitation experiments using biotin-labeled peripheral blood mononuclear cells suggested, but did not conclusively establish, that each of these antibodies recognized a different epitope. The epitope identified by IL-A21 appeared to be common to all of the class II proteins precipitated by the four mAbs, and UC-D3 and UC-H9 each appeared to react with distinct epitopes on separate subsets of these class II proteins. Monoclonal antibody UC-A4 appeared to identify an epitope on a subset of the class II molecules identified by UC-H9. Differences found in the expression by lymphoid cells of class II proteins identified by the four mAbs were indicative of each mAb recognizing a different epitope. UC-H9 and IL-A21 class II proteins were detected on all surface immunoglobulin (S'Ig) positive cells in peripheral blood, but UC-A4 and UC-D3 class II proteins were not. Expression of UC-A4 class II proteins, detected at low density on a strikingly reduced number of S'Ig+ cells from the blood of some bovine leukosis virus-infected cattle, could be increased by culturing these B cells with lipopolysaccharide. All peripheral blood monocytes expressed UC-H9 and IL-A21 class II proteins, but only a proportion of monocytes expressed detectable UC-A4 and UC-D3 class II proteins. Almost all mitogen-stimulated BoCD4+ and BoCD8+ T cells expressed UC-H9 and IL-A21 class II proteins, whereas fewer stimulated T cells of both subsets expressed UC-A4 and UC-D3 class II proteins. All gamma/delta receptor (gamma/delta R) T cells expressed UC-D3, UC-H9, and IL-A21 class II proteins, but no cells (of gamma/delta R+ or CD4+/CD2+ phenotype) from gamma/delta R+ T cell-enriched cultures expressed UC-A4 class II proteins.
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Taylor BC, Stott JL, Scibienski RJ, Redelman D. Development and characterization of a monoclonal antibody specific for the bovine low-affinity interleukin-2 receptor, BoCD25. Immunol Suppl 1992; 77:150-4. [PMID: 1398763 PMCID: PMC1421608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
An IgM monoclonal antibody, UC-2C2 was produced using splenocytes from mice immunized with cultures of interleukin-2 (IL-2)-dependent bovine peripheral blood lymphocytes. UC-2C2 was found to recognize a cell surface antigen of apparent molecular weight 52,000-54,000 present on activated bovine peripheral blood mononuclear leucocytes (PBML) but not on resting PBML or cells of the bovine lymphoblastoid cell line BL3. The 52,000-54,000 MW antigen was expressed early following activation of PBML by mitogens or alloantigens, with the majority of cells positive by 48 h of culture. UC-2C2 was unable to block binding of phycoerythrin (PE)-conjugated human recombinant IL-2 to PHA-stimulated bovine PBML as determined by flow cytometric analysis. However, two-colour analyses indicated that the antigen recognized by UC-2C2 was present on the same cell population that expressed IL-2 receptors. All activated T lymphocytes of BoCD4, BoCD8 and gamma delta receptor positive phenotypes expressed the target antigen of UC-2C2 and IL-2 receptors. Monocytes and B lymphocytes expressed the target antigen of UC-2C2 and IL-2 receptors at a lower density. This differential expression by the various PBML subpopulations parallels that described for expression of the low-affinity IL-2 receptor (CD25) on human leucocyte subpopulations. Based upon the relative molecular weight, time-course of expression and cellular distribution of the antigen identified by UC-2C2, it is inferred that UC-2C2 recognizes an epitope on the bovine homologue of CD25 which is not involved in binding IL-2.
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Taylor BC, Stott JL, Thurmond MA, Picanso JP. Alteration in lymphocyte subpopulations in bovine leukosis virus-infected cattle. Vet Immunol Immunopathol 1992; 31:35-47. [PMID: 1570682 DOI: 10.1016/0165-2427(92)90085-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Alterations in peripheral blood lymphocyte subpopulations were examined in bovine leukosis virus (BLV)-infected cattle using antibodies specific for differentiation antigens in conjunction with analytical flow cytometry. Animals considered to be aleukemic and lymphocytotic were included in the study. Significantly fewer numbers of circulating B-lymphocytes (surface Ig-positive) and T-helper lymphocytes (BoCD4-positive) were identified in BLV-infected aleukemic cattle compared to non-infected controls while no significant differences were established for T-cytotoxic/suppressor lymphocytes (BoCD8-positive). In contrast, BLV-infected animals with persistent lymphocytosis had elevated numbers of circulating B-lymphocytes with no significant perturbation in circulating T-lymphocyte subsets identified when compared as a group with the negative control cattle. Application of regression analysis to data from individual lymphocytotic cattle demonstrated a significant correlation between absolute numbers of B- and T-lymphocytes. Increased numbers of B-lymphocytes were correlated with increased numbers of T-helper and T-cytotoxic/suppressor lymphocytes.
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Donovan FM, Taylor BC, Su MC. One-dimensional computer analysis of oscillatory flow in rigid tubes. J Biomech Eng 1991; 113:476-84. [PMID: 1762446 DOI: 10.1115/1.2895429] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The dynamic characteristics of catheter-transducer systems using rigid tubes with compliance lumped in the transducer and oscillatory flow of fluid in rigid tubes were analyzed. A digital computer model based on one dimensional laminar oscillatory flow was developed and verified by exact solution of the Navier-Stokes Equation. Experimental results indicated that the damping ratio and resistance is much higher at higher frequencies of oscillation than predicted by the one dimensional model. An empirical correction factor was developed and incorporated into the computer model to correct the model to the experimental data. Amplitude of oscillation was found to have no effect on damping ratio so it was concluded that the increased damping ratio and resistance at higher frequencies was not due to turbulence but to two dimensional flow effects. Graphs and equations were developed to calculate damping ratio and undamped natural frequency of a catheter-transducer system from system parameters. Graphs and equations were also developed to calculate resistance and inertance for oscillatory flow in rigid tubes from system parameters and frequency of oscillation.
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Culbertson WW, Brod RD, Flynn HW, Taylor BC, Brod BA, Lightman DA, Gordon G. Chickenpox-associated acute retinal necrosis syndrome. Ophthalmology 1991; 98:1641-5; discussion 145-6. [PMID: 1666176 DOI: 10.1016/s0161-6420(91)32061-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Acute retinal necrosis (ARN) syndrome usually occurs as the result of secondary reactivation of latent, previously acquired, varicella-zoster or herpes simplex virus. The authors report four patients who developed a mild form of ARN within 1 month (5 to 28 days) after the onset of chickenpox. In contrast to typical cases of ARN, these cases were less severe, with retinitis limited to two quadrants or less (three patients), no retinal detachment (four patients), minimal vitreitis (four patients), and no loss of visual acuity (four patients). Thus, ARN may occur during the course of primary varicella-zoster infection.
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Taylor BC, Sheffer DB. Understanding techniques for measuring cardiac output. Biomed Instrum Technol 1990; 24:188-97. [PMID: 2188704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In summary, use of thermodilution as a method to measure cardiac output has attained universal appeal in the clinical environment. Other means of detecting cardiac output (impedance-cardiogram and ballistocardiogram, to name two) have been developed and are being used clinically, but the development of the flow-directed thermodilution catheter has profoundly affected the universal acceptance of the thermodilution method. Thermodilution techniques, when performed properly, are capable of obtaining accurate and reproducible results. Medical and nursing personnel who are educated in proper procedures will be able to make educated choices when faced with difficult decisions. It is likely that they will turn to the biomedical or clinical engineering department for help if those personnel are well informed regarding the techniques and procedures.
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Taylor BC, Ellis DM, Drew JM. Quantification and simulation of fluid-filled catheter/transducer systems. MEDICAL INSTRUMENTATION 1986; 20:123-9. [PMID: 3724585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Optimization of fluid-filled catheter/transducer systems for blood pressure measurement requires a prior knowledge of how each component affects overall dynamic response. This paper presents a method to measure resistance, inertance, and compliance of individual components by investigating the causal relationships between added known compliances and resonance. Additionally, a computer simulation that combines individual component values to synthesize practical blood pressure monitoring systems is presented. Complete monitoring systems are modeled through the combination of characterized components such as transducers, monitoring lines, and catheters and used to predict overall system response to any input function.
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Abstract
Eighteen patients (19 eyes) developed retinal complications following YAG laser capsulotomy. Complications included one retinal flap tear, two macular holes, six eyes with cystoid macular edema, and ten retinal detachments. The retinal complications resulted from opening the capsule and were not a specific complication of the YAG laser.
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Taylor BC, Winslow RL. Pseudophakic flat anterior chamber following retinal detachment repair. Ophthalmology 1981; 88:935-41. [PMID: 7301310 DOI: 10.1016/s0161-6420(81)80008-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Flat anterior chambers were caused by varying mechanisms in 10 of 70 consecutive pseudophakic eyes operated on for retinal detachment. With iris or capsular implant fixation, three of 46 (7%) developed flat anterior chambers, and with anterior chamber lenses, the occurrence was seven of 24 (29%). Events initiating flat chambers included wound leak, pupillary block, and choroidal detachment. In eyes with flat anterior chambers, the retina could not be reattached in one case, extensive peripheral anterior synechia with persistent intraocular pressure elevation occurred in another case, and bullous keratopathy remained in two additional instances. Endothelial cell densities were obtained in eight eyes and were low on an age-related basis.
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Abstract
Spontaneous vitreous hemorrhage, without trauma, accounted for 317 patients (375 eyes) seen during a four-year period from July 1, 1975, to June 30, 1979. The most common causes were proliferative diabetic retinopathy, 39.2%; retinal tear, 12.1%; posterior vitreous detachment, 12%; vein occlusion, 10.4%; retinal detachment, 6.7%; intraocular lens, 3.2%; proliferative sickle retinopathy, 1.3%; miscellaneous, 7.4%; and unknown, 6.7%. Emphasis is placed on the importance of establishing the specific cause so that specific therapy may be instituted.
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Winslow RL, Taylor BC, Harris WS. A one-year follow-up of cystoid macular edema following intraocular lens implantation. Ophthalmology 1978; 85:190-6. [PMID: 643254 DOI: 10.1016/s0161-6420(78)35680-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Retrospective and prospective techniques were used to analyze a consecutive series of 406 eyes to identify factors contributing to cystoid macular edema following lens implantation. Vitreous loss and rupture of the posterior capsule were highly significant in the production and persistence of this complication.
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Harris WS, Taylor BC, Winslow RL. Cystoid macular edema following intraocular lens implantation. OPHTHALMIC SURGERY 1977; 8:134-7. [PMID: 904865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This presentation recounts the original description of CME and the more recent developments associated with intravenous fluorescein angiography in its study and diagnosis. The work of previous authors to show the incidence of CME and its possible prognosis are reviewed. Our findings in a retrospective study agree with the other authors and show that there is no particular increase in CME following intraocular lens implantation regardless of the type of surgical procedure used. It is established that vitreous loss does increase the incidence of CME. A prospective study with routine intravenous fluorescein at six weeks is presented and shows an incidence that is below that found by other authors when it was performed following routine intracapsular cataract extraction.
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Clark P, Crawford H, Sims JL, Taylor BC, Meyer OO. Memorial resolution on the death of William Shainline Middleton, MD. WISCONSIN MEDICAL JOURNAL 1976; 75:28-9. [PMID: 1108458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Taylor BC, Davison TW, Sharp WV, Wright J, Rubal B, Malin K. Dynamic fatigue evaluation of artificial hearts by thermal gradient visualization. TRANSACTIONS - AMERICAN SOCIETY FOR ARTIFICIAL INTERNAL ORGANS 1973; 19:561-6. [PMID: 4722773 DOI: 10.1097/00002480-197301900-00099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Sharp WV, Taylor BC, Wright JI, Nuwayser E, Miller BG, Hampton GR, Wilson CL. Neointimal survival - a function of attachment and thickness. TRANSACTIONS - AMERICAN SOCIETY FOR ARTIFICIAL INTERNAL ORGANS 1972; 18:232-8. [PMID: 4279486 DOI: 10.1097/00002480-197201000-00058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Sharp WV, Taylor BC, Finelli AF, Wright J. Experience with negatively charged polyurethane-backed velours. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1971; 5:75-81. [PMID: 5575330 DOI: 10.1002/jbm.820050209] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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