Search

The authors previously identified plasma plasminogen activator inhibitor-1 (PAI-1) level as a quantitative lung injury biomarker in primary graft dysfunction (PGD). They hypothesized that plasma levels of PAI-1 used as a quantitative trait could facilitate discovery of genetic loci important in PGD pathogenesis. A two-stage cohort study was performed. In stage 1, they tested associations of loci with PAI-1 plasma level using linear modeling. Genotyping was performed using the Illumina CVD Bead Chip v2. Loci meeting a p5 × 10(-4) cutoff were carried forward and tested in stage 2 for association with PGD. Two hundred ninety-seven enrollees were evaluated in stage 1. Six loci, associated with PAI-1, were carried forward to stage 2 and evaluated in 728 patients. rs3168046 (Toll interacting protein [TOLLIP]) was significantly associated with PGD (p = 0.006). The increased risk of PGD for carrying at least one copy of this variant was 11.7% (95% confidence interval 4.9-18.5%). The false-positive rate for individuals with this genotype who did not have PGD was 6.1%. Variants in the TOLLIP gene are associated with higher circulating PAI-1 plasma levels and validate for association with clinical PGD. A protein quantitative trait analysis for PGD risk prioritizes genetic variations in TOLLIP and supports a role for Toll-like receptors in PGD pathogenesis.

An application of the linear programming (LP) approach to form and position accuracy assessments based on the minimum zone (MinZ) method is considered. The standard form of the optimization function and constraints using linearized form of the substitute feature is considered. A linearization-caused error is estimated by reference to the second order terms within the Taylor series expansion of the rotation matrix. The acceptable range of the LP-based assessments is defined for some levels of an allowable error. The LP-based assessment for a surface is simulated. Actual measurements show that the LP-based estimations have equal or fewer values in comparison with those obtained by other methods.

Affinity purified, freshly isolated CD34+ progenitors were shown to express low levels of type I interferon (IFN) receptors (740 +/- 60 binding sites/cell, K(d) 0.7 +/- 0.04 nM) determined by Scatchard's analysis using a radiolabelled, neutralizing, monoclonal antibody directed against the IFNAR1 chain of the human type I IFN receptor. Treatment of freshly isolated (day 0), highly purified (>95% pure) CD34+ cells with recombinant IFN-alpha resulted in rapid tyrosine phosphorylation and activation of STAT1, Tyk2 and JAK1 as shown by Western immunoblotting. Similarly, IFN treatment was shown by confocal microscopy to result in rapid nuclear localization of the transcription factors IRF1 and STAT2, demonstrating the presence of functional IFN receptors on freshly isolated (day 0) CD34+ cells. The number of specific type I IFN receptor binding sites expressed on hematopoietic progenitor cells increased to some 1440 +/- 40 per cell after 11 days of cultivation of CD34+ cells in vitrosuggesting that receptor expression increases with cell differentiation. IFN-mediated signal transduction and the inhibitory effect of IFN-alpha on 7 or 14 days CFU-GM and BFU-E colony formation was abrogated in the presence of the anti-IFNAR1 mAb, indicating that IFN-alpha acts directly on the proliferation of human hematopoietic progenitor cells via receptor activated signal transduction without excluding the induction of other cytokines or growth factors by residual accessory cells.

Background: Conventional adrenalectomy usually necessitates a large incision. In some cases, laparoscopic adrenalectomy offers a less aggressive solution to the patient's problem. Patients and Methods: Laparoscopic adrenalectomy for clearly defined lesions was performed in five girls and nine boys with a mean age of 9 years. The indication was incidental discovery in four patients, hypertension in six (two of whom had von Hippel Lindau syndrome), Cushing's disease in two, and gynecomastia or premature puberty in one patient each. The lesion was on the right side in five patients and the left side in six and was bilateral in three. The mean diameter was 35 mm. The urinary concentrations of vanillylmandelic acid and homomandelic acid were normal in five patients with neurogenic tumors and elevated in five patients with pheochromocytoma. An anterior transabdominal approach was used in nine patients and a lateral retroperitoneal approach in seven. Results: The operating time ranged from 35 to 320 minutes. The...

Second and higher-order approximations for machine accuracy calculations are necessary when the precision of the error estimation obtained on the basis of the first order approximations is poor or when first order approximations are not influencing the output accuracy of the machine. This latter case is widely present in the calculations of the functional accuracy of machines, in particular when estimating the machine tool set-up errors or when calculating the influence of machine setting displacements. In the case of machining operations, the second order approximation for the normal position error of the real surface relative to the nominal one is shown to depend on the second fundamental form of the nominal surface. As a real world application, the setting of a grinding machine for a crowned conic surface grinding operation is calculated.

Infiltration of the synovium by mononuclear cells, namely lymphocytes and monocytes, is one of the main features of rheumatoid arthritis (RA) and is considered to be responsible for the development of the disease. In this study in 31 consecutive patients with RA, we investigated whether peripheral blood monocytes exhibited markers of cellular activation related to cell migration. Using flow cytometry with the respective specific antibodies, we studied the expression of integrins CD11a, CD11b, CD11c, CD49d (VLA-4), and CD49e (VLA-5) on monocytes from patients with RA and from normal (N) subjects. IL-1β, IL-6, and tumour necrosis factor-alpha (TNF-α) production by cultured monocytes was measured by immunoassay. Adhesiveness of monocytes was studied on various surfaces (plastic, human fibronectin, gelatin-coated plasma, subendothelial matrix) and on cultured endothelial cells under basal conditions or after stimulation by IL-1β. An increased number of CD14+ monocytes (Mo) from RA patients expressed the CD11b molecule (RA Mo = 90.3%, N Mo = 83.4%, P

The authors develop a theory within the effective-mass approxn. of the 2nd-order susceptibility of a quantum well subject to an applied elec. field. Close to the midgap of the structure it is possible within that approxn. to reduce the normally derived triple sums over subbands to a simple sum over all the optically allowed transitions. In realistic structures, higher-energy transitions play a strong role for quant. results. This strong influence of the higher-energy transitions on the 2nd-order susceptibility has the consequence that it is not generally possible to define a quantum-well susceptibility independent of the structure in which the well is inserted. Numerical results indicate that the quantum wells should not lead to spectacular enhancements of the 2nd-harmonic-generation susceptibility. [on SciFinder (R)]

Background: Conventional adrenalectomy usually necessitates a large incision. In some cases, laparoscopic adrenalectomy offers a less aggressive solution to the patient's problem. Patients and Methods: Laparoscopic adrenalectomy for clearly defined lesions was performed in five girls and nine boys with a mean age of 9 years. The indication was incidental discovery in four patients, hypertension in six (two of whom had von Hippel Lindau syndrome), Cushing's disease in two, and gynecomastia or premature puberty in one patient each. The lesion was on the right side in five patients and the left side in six and was bilateral in three. The mean diameter was 35 mm. The urinary concentrations of vanillylmandelic acid and homomandelic acid were normal in five patients with neurogenic tumors and elevated in five patients with pheochromocytoma. An anterior transabdominal approach was used in nine patients and a lateral retroperitoneal approach in seven. Results: The operating time ranged from 35 to 320 minutes. There were three conversions to open surgery (20%). There were no perioperative or postoperative complications. Histologic examination revealed 13 benign lesions (7 pheochromocytomas, 3 ganglioneuromas, 2 cortical adenomas, and 1 hyperplasia), 1 malignant lesion (N-Myc-negative neuroblastoma, which was removed after conversion to open surgery), and two indeterminate lesions. Of the latter lesions, one was an N-Myc-negative gangioneuroblastoma, and the other was an adrenocortical tumor that was treated initially by local excision and 1 month later by total adrenalec via an open approach. There were no tumor remnants in the specimen. All patients are alive without evidence of recurrence with follow-up of 6 months to 4 years. Conclusions: The laparoscopic approach should be reserved for well-defined lesions

Summary Absolute accuracy of robots has been plaguing designers of industrial robots since the beginning of the robot era. Several models of robot errors have been developed recently, but non is considering all types of errors occuring in the links and joints of robots. Therefore, a new model taking in account all errors of position and orientation at the end effector as a function of the geometrical errors in the links was developed. A graphical program enables a coloured mapping of the errors in the whole workspace of the robot for typical sets of errors in the links. The relation between the error parameters in the model and the standardised definition of geometical tolerances is established.

A wide variety of medications is commonly used following thoracic surgical procedures. All of these medications have associated side effects that may adversely affect the recovery of patients. A complete understanding of the important adverse effects of all the medications used postoperatively can limit or eliminate unwanted medication effects and lead to a more successful outcome. This article will review the important actions and side effects of the most commonly administered medications following thoracic surgical procedures.

Acute rejection after lung transplantation occurs commonly and is usually characterized histologically by a perivascular mononuclear infiltrate. We report five cases of pulmonary capillaritis with a histologic appearance distinct from typical rejection, occurring in patients ranging in age from 18 to 45 years, with a variety of underlying diseases including alpha1 antitrypsin deficiency, pulmonary hypertension, cystic fibrosis, and rheumatoid arthritis. Four of the five patients had alveolar hemorrhage histologically, and two had frank hemoptysis. Time of onset ranged from 3 weeks to many months after transplantation. Three cases were fulminant, and there were two deaths. In only one case, with methicillin-resistant Staphylococcus aureus bronchitis, could infection be established. All were treated with intensification of immunosuppressive therapy. Plasmapheresis was carried out in two cases and coincided with temporary improvement, but its efficacy was questionable because of concurrent immunosuppressive therapy. Two had recurrent biopsy-proven acute rejection within 6 weeks of treatment, and one had recurrent severe pulmonary hemorrhage that abated with total lymphoid irradiation. Our experience suggests that pulmonary capillaritis in lung transplant recipients can be an acute, fatal illness with the potential for recurrence in the survivors. We speculate that it represents a form of acute vascular rejection. Early pathologic diagnosis and aggressive immunosuppressive therapy are recommended. Although a humoral component was not documented, the possible response to plasmapheresis requires continued evaluation.

A standard analytical presentation for the minimal-zone-based tolerancing is proposed. For this purpose, the form-invariant vector (FIV) of elementary errors is formulated; small deviations of the FIV components leave the predetermined form of the toleranced feature unaltered. Then, the toleranced features are presented in terms of the FIV components, and a set of constraints is presented in terms of the transfer factors for these components. The set of the constraints and the results of the measurements of the real feature enable us to obtain a standard presentation of the linear-programming problem, which is solved with respect to the FIV. A comparison of this solution with the least-mean-square-based assessment is given. Both well-studied cases (accuracy of a plane and a cylinder) and more complicated cases, such as the tolerancing of the helical surfaces, element-by-element analysis of the form accuracy, etc., are considered in order to illustrate the applications of the theoretical results.

An analytical and computational procedure for modelling spatial dimensional chains (DC) is based on the kinematic interpretation both of nominal dimensions forming the DC and their errors. The goal of the investigation is to assess the accuracy of the closing link of the DC, taking into account the errors of the intermediate links of the DC. The three-stage procedure successively models the nominal DC, the actual DC with positional errors of the links, and the metrological estimations of the accuracy. The latter stage is undertaken using metrological models of accuracy, which brings the accuracy estimation into conformity with a nominal form of the boundaries of the DC’s closing link and the relative positions of the boundaries. The theoretical results apply to important design problems: evaluating closing tolerances, choosing compensating links, and structural optimization of the DC according to accuracy criteria. As an example, calculation of the spatial DC between two perpendicular bores is considered.

Leukocyte adhesion to endothelium is dependent on expression of specialized molecules. Several of these molecules are upregulated by cytokines such as interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha). We investigated the effect of medium conditioned by unstimulated (MCM) or stimulated monocytes and of recombinant cytokines on endothelial adhesion receptor expression. IL-1 beta, TNF-alpha, and MCM induced E-selectin similarly, whereas MCM induced VCAM-1 and ICAM-1 to a lesser extent than did TNF-alpha, and MCM induced VCAM-1 only weakly. The addition of pentoxifylline (10(-3) mol/L) to monocytes during MCM preparation blocked TNF-alpha production but not that of IL-1 beta or IL-6, and it reduced IL-1ra significantly (p0.05). When the MCM was devoid of TNF-alpha or when TNF-alpha was neutralized with a specific antibody, the action of MCM on E-selectin expression was significantly lower. Anti-IL-1 beta decreased the activity of MCM on endothelial E-selectin expression by about 50%. The effect of MCM on adhesion molecules was accompanied by an increase in monocyte adhesion. Inhibition of TNF-alpha production reduced monocytes adhesion slightly but significantly (18%, p0.05), whereas anti-IL-1 beta antibody decreased adhesion by 48% (p0.001). These results show that adherent monocytes released cytokines and antagonists that affect leukocyte adhesion receptors on endothelium differently from recombinant cytokines. E-selectin expression--and to a lesser extent ICAM expression--is modified, resulting in a modulation of leukocyte adhesion to endothelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Hole producing seems at first sight to be a simple task. However, there are so many tools and process options available for this operation that care must be taken to select a process which minimizes cost and machining time. The scatter of hole-making time and cost can be within a range of up to 10:1, as shown in Table 6.1.

Statistical process control (SPC) is a technique for error prevention rather than error detection. SPC products will be of the required quality because they are manufactured properly rather than because they are inspected. Thus, it increases productivity by reducing scrap and rework and provides continuous process improvement. Other methods — such as flexible manufacturing systems (FMS), computer integrated manufacturing (CIM) and just-in-time (JIT) — which have aimed at increasing productivity, concentrate on hardware flexibility, integration of information flow or reduction of inventory. Seldom does a system use technology flexibility to produce the correct product.

Wir entwickelten seit 1982 mit dem inzwischen leider verstorbenen Otto Frey eine eigene, unzementierte Schraubpfanne und berichten hier uber unsere Erfahrungen, die wir in uber 10 Jahren sammeln konnten. In diesem Zeitabschnitt wurden allein vom Autor mehr als 2100 solcher Schraubpfannen implantiert.

Having analyzed the different aspects of planning the manufacturing of a mechanical part in the previous chapters, it seems appropriate now to apply these general rules to a specific example. The part used in this example is represented in Fig. 16.1.

To give a global idea of the preparation of a process plan, it seems appropriate to analyze a typical mechanical part and to define the different stages of decisions to be taken. The intention is not to present a complete set of methods of analysis — these are developed in the course of the book — but, rather, to give a general feeling of the nature of process planning as an introduction to the following chapters.

When a technical drawing of a mechanical part is handed over to the production planning department, this drawing must be considered as a contract, to be honored in all its details. This drawing, prepared by the design department, expresses certain functional requirements which have been defined in relation to the functionality of the part in the framework of the complete product.

Together with the late Otto Frey we have been concerned with the development of our own, cementless self-tapping cup since 1982. We report our personal experience gathered over a period of 10 years. During this time the author has implanted more than 2100 of these CLW cups.

In order to produce a mechanical part correctly, it must be on a suitable set-up (or jig) which guarantees a well-defined location (position and orientation) in space. The surfaces of the jig represent data references for the coordinate system in which the different features of the part are defined. As an example, Fig. 7.1 shows a prismatic part located on three orthogonal planes simulating datum surfaces existing in the physical jig. These planes are used to set the manufacturing dimensions of the features in the part. As mentioned already in Chapter 2, the exact definition of datum features is found in a recent standard (ISO Standard 5459, 1981) distinguishing between simulated and real datum surfaces.

In spite of the importance of process planning in the manufacturing cycle, it is still predominantly a labor-intensive activity, leaning heavily on experience, skill and intuition. Dependence on practical experience often precludes a thorough analysis and optimization of the process plan and nearly always results in higher-than-necessary production costs, delays, errors and non-standardization of processes.

Forming material removal is a most comprehensive process. There is almost an infinite number of combinations of machines and tools that will produce the part as specified by the drawing. However, cost and machining time will vary substantially according to the selected process. Therefore, it requires a skillful handling of the operating conditions in order to arrive at the economic optimum. In this respect, the sensitivity of the machining conditions in relation to the time and cost of machining, can be seen in the following examples.

The selection of tools for a job involves many parameters, such as, insert shape, insert grade, tool holder type, method of holding the insert in the holder, etc. Furthermore, there are many tool manufacturers offering a large variety of tools. Only standard tools will be considered. It is not the purpose of this book to promote the use of special tools that may perform an operation in a more efficient way.

A part is defined by an engineering drawing which gives complete information on its geometry and associated data. It is the fundamental means of communication between the designer, the process planner and all other functions in the enterprise; it is the medium by which the designer’s intentions and wishes are expressed in an unambiguous manner.

Gene expression studies require a sensitive and quantitative assay of mRNA amounts present in small samples. We describe a general method of quantifying specific mRNA quickly and easily from purified RNA or directly from a few cells by PCR and enzyme-linked immunosorbent assay (ELISA) revelation of the resulting products (sensitivity of the last step:0.1 fmol). Cells are digested and the total cellular RNA is reverse-transcribed and then amplified with 5' and 3' primers; the former being 5' biotinylated. The amplification product is captured on avidin-coated microplates and quantified by hybridization with a digoxigenin-labeled internal oligonucleotide probe. After revelation with an anti-digoxigenin alkaline phosphatase coupled antibody (anti-DIG-AP1), the amount of hybridized probe is determined by optical reading. The results can be easily converted to absolute values by comparison with an external DNA standard curve. An internal DNA or RNA standard can also be used. The method we describe can be adapted to any cellular or viral gene of known sequence in a matter of days. Since it uses nonradioactive probes, commercially available reagents and standard microplate readers, it is inexpensive and could be automated easily. In this study, interleukin-2 mRNA expression could be studied in as few as 40 Jurkat cells. It was also possible to quantify human immunodeficiency virus (HIV) DNA from 1500 to 1.5 copies out of 1.5 x 10(5) human genomic DNA copies.