Post-chemotherapy and cytokine pretreated marrow stromal cell layers suppress hematopoiesis from normal donor CD34+ cells

Marrow stromal layers were used to investigate the potential role of negative regulators produced by the marrow microenvironment as one potential cause of hematopoietic suppression after chemotherapy and cytokines. Stromal layers were established from marrow of normal or prechemotherapy donors and breast cancer patients after hematological recovery from one cycle of 5-fluorouracil, leucovorin, doxorubicin, and cyclophosphamide and GM-CSF or PIXY321 (GM-CSF/IL-3 fusion protein). Normal donor CD34+ cells were placed in contact with stromal layers, and the number of colony-forming units for granulocytes and macrophages (CFU-GM) was determined. There were 25-79% fewer CFU-GM in post-chemotherapy stromal layer cocultures than in no chemotherapy cocultures. With neutralizing antibody to TNF-alpha the number of CFU-GM in no chemotherapy and post-chemotherapy stromal cocultures was, respectively, 96 +/- 7% (n = 5) and 142 +/- 8% (n = 5) of the number with no antibody treatment. PIXY321 and GM-CSF pretreated stromal layers also suppressed production of CFU-GM. Anti-TNF-alpha promoted an increase in CFU-GM numbers from GM-CSF, but not PIXY321, pretreated stromal cocultures. The results demonstrate that post-chemotherapy marrow stromal layers were deficient in supporting in vitro hematopoiesis and suggest that negative regulators induced by chemotherapy and cytokines may be one cause for this defect.     

Synthesis of polyribonucleotide chains from the 3'-hydroxyl terminus of oligodeoxynucleotides by Escherichia coli primase

Escherichia coli primase synthesizes RNA primers on DNA templates for the initiation of DNA replication. The sole known activity of primase is to catalyze synthesis of short RNA chains de novo. We now report a novel activity of primase, namely that it can synthesize RNA from the 3'-hydroxyl terminus of a pre-existing oligodeoxynucleotide. The oligonucleotide-primed synthesis of RNA by primase occurs in both of the G4oric-specific priming system and the dnaB protein associated general priming system. This priming reaction of primase is verified by a number of biochemical methods, including inhibition by modified 3'-phosphate of oligonucleotides and deoxyribonuclease I and ribonuclease H cleavages. We also show that the primed RNA is an effective primer for the synthesis of DNA chain by E. coli DNA polymerase III holoenzyme. The significance of this finding to primases generating multimeric length RNA is discussed.     

Pulmonary vein stenosis after catheter ablation of atrial fibrillation

BACKGROUND: This report describes the complication of pulmonary vein stenosis with resultant severe pulmonary hypertension that developed in 2 patients after successful catheter ablation of chronic atrial fibrillation. METHODS AND RESULTS: Three months after successful catheter ablation of atrial fibrillation, both patients developed progressive dyspnea and pulmonary hypertension. Both were found to have severe stenosis of all 4 pulmonary veins near the junction with the left atrium. Balloon dilation of the stenotic pulmonary veins was performed in these patients, with improvement in dyspnea and pulmonary hypertension. CONCLUSIONS: The complication of pulmonary vein stenosis is potentially life-threatening, and the application of radiofrequency current within the pulmonary veins with standard catheter technology should be avoided. This complication can be treated with balloon dilation, although the long-term course is unknown.     

Thermal performance of “still on roof” system

This paper presents an analysis of periodic heat flux through a roof, on which a solar still has been placed. It is seen that on a typical hot day in Delhi, for high reflectivity of the bottom of the basin (on account of deposits or otherwise) the daily heat flux in the room gets reduced by 40% and the production of distilled water is 0.6 kg/m² day; the produced swings in the heat flux also get reduced in magnitude. For a typical cold day in Delhi, if a black dye is mixed with basin water the daily heat flux in the room increases by a factor of two and the yield of the distillate becomes 5.0 kg/m² day.     

Early user involvement in the development of information technology-related products for older people

The UTOPIA project (Usable Technology for Older People—Inclusive and Appropriate) is focused on developing effective methods for the early involvement of older people in the development of information technology-related products for people aged 60 and over, and on providing industry with tools to assist in the development of information technology products for such older people. An essential part of this methodology is building a diverse user base, forming a long-lasting partnership with older people, and developing approaches for effective interaction with this target user group. Our experiences with eliciting information from groups of older people about technology is described, together with a report on seminars for Scottish industry designed to raise an awareness of these issues.     

Effect of a thermal trap on the performance of a solar sand collector

The effects of different parameters—e.g. the thickness of the trap material, the flow rate of the water and the depth of the heat-retrieval plane—on the water temperature have been investigated. A comparison of the present system with a conventional solar sand collector was also made.     

Effect of a booster mirror on the performance of a ‘built-in’ storage solar water heater

In this paper, the performance of a ‘built-in’ storage solar water heater-flat mirror system has been presented. Numerical calculations have been made for a typical cold day (viz. 28 Jan. 1980) at Delhi. The booster mirror causes a minimum temperature rise during the moring and a temperature difference of 7°C excess with respect to the reference panel occurred. The reflectance of the mirror is taken as 0·88.     

Process control in CNC manufacturing for discrete components: A STEP-NC compliant framework

With today's highly competitive global manufacturing marketplace, the pressure for right-first-time manufacture has never been so high. New emerging data standards combined with machine data collection methods, such as in-process verification lead the way to a complete paradigm shift from the traditional manufacturing and inspection to intelligent networked process control. Low-level G and M codes offer very limited information on machine capabilities or work piece characteristics which consequently, results in no information being available on manufacturing processes, inspection plans and work piece attributes in terms of tolerances, etc. and design features to computer numerically controlled (CNC) machines. One solution to the aforementioned problems is using STEP-NC (ISO 14649) suite of standards, which aim to provide higher-level information for process control. In this paper, the authors provide a definition for process control in CNC manufacturing and identify the challenges in achieving process control in current CNC manufacturing scenario. The paper then introduces a STEP-compliant framework that makes use of self-learning algorithms that enable the manufacturing system to learn from previous data and results in eliminating the errors and consistently producing quality products. The framework relies on knowledge discovery methods such as data mining encapsulated in a process analyser to derive rules for corrective measures to control the manufacturing process. The design for the knowledge-based process analyser and the various process control mechanisms conclude the paper.