The microsurgical treatment of large and giant aneurysms of the internal carotid artery located parasphenoidally

Internal carotid aneurysms in the ophthalmic area presents a challenge in cerebrovascular neurosurgery. The study was undertaken to provide evidence for the application of intravascular aspiration during direct surgical interventions and to outline their variants used at the N. N. Burdenko Institute of Neurosurgery. The study included 4 (3 females and 1 male) patients with large and giant internal carotid aneurysms of parasphenoidal site who were treated at the Institute. Clipping of the aneurysmal neck was made by employing intravascular blood aspiration from the aneurysm. The technique proved to be effective in proximal monitoring the carotid artery at surgery. It substantially reduced aneurysmal blood flow and wall tension, thus favouring aneurysmal dissection to make clipping.     

Experimental-morphological and clinical basis of preventive methods for the intraoperative complications of the amputation of the lower extremity at the thigh level]

Using total quality management principles within a shared governance framework, this case study discusses how to design and implement a plan to achieve independent nursing practice when an employee has unique needs. This experience demonstrates the importance of looking at root causes, separating ability and compliance issues, using all available resources creatively, and planning for success.     

Low-Temperature Cyaniding of High-Speed Steels in Hydrogen-Free Plasma

Results of saturation of some high-speed steels with nitrogen in hydrogen-free plasma of glow discharge are presented. The distribution of carbon and nitrogen in surface layers, and their phase composition and wear resistance are determined. It is shown that the wear resistance of steels after low-temperature cyaniding in hydrogen-free plasma is much higher than after conventional saturation.     

Operation mode of the proton injector in the linac of the Institute for Nuclear Research with a 100-Hz pulse repetition rate

Results of the analysis and upgrading of the high-voltage pulse generator circuit in the proton injector for operation with a 100-Hz pulse repetition rate are presented.     

Perioperative risk factors affecting hospital stay and hospital costs in open heart surgery for patients > or = 65 years old

OBJECTIVE: Demographic changes, associated with increased demands for open heart surgery in the elderly, place increased burden on financial resources. To evaluate perioperative risk factors affecting incidence of hospital events and estimation of hospital charges, 2577 patients > or = 65 years (range 65-91), operated on from January 1991 to December 1994, were compared with a concurrent cohort of 2642 younger patients. METHODS: Statistical analysis, by surgical procedure, focused on hospital mortality, key postoperative complications affecting length of hospital stay and hospital charges. RESULTS: Overall hospital mortality was 4.7%, 3.5% in younger patients versus 6.1% in the older group (P < 0.01). Mortality was significantly lower in patients less than 65 years undergoing coronary artery bypass grafting (3% versus 5%, P < 0.01) and valve replacement (4% versus 9%, P = 0.01). Significant risk factors for hospital death in the elderly: diabetes (P < 0.01), hypertension (P < 0.01), myocardial infarction (P < 0.01) and congestive heart failure (P < 0.01). Significant postoperative events, more common in older patients, included prolonged ventilation (P < 0.01), congestive heart failure (P < 0.01), infection (P < 0.01), cerebrovascular accident (P < 0.01), and intra aortic balloon pump (P < 0.01). Incremental risk factors for morbidity in the elderly were: higher New York Heart Association class, congestive heart failure, emergent operation, and female gender. Mean length of hospital stay for the < 65 group was 15.3 versus > 19.5 days for the > 65 group (P < 0.01). Length of stay over 18 days positively correlated with increased morbidity in both age groups. For patients > or = 65 years of age, the average hospital charge for open heart surgery was 172% higher for patients with a length of stay greater than 18 days compared with 165% for patients less than 65 years of age. CONCLUSIONS: Higher operative mortality and longer length of stay in elderly patients, resulting in increased health care costs, was associated with more co-morbidities. These results suggest interventions designed to reduce congestive heart failure and other co-morbidities may improve patient's recovery and reduce costs.     

Rapid assessment of onchocerciasis prevalence and a model for selecting communities for ivermectin distribution in West Africa

A major obstacle to stem cell gene therapy is the extremely low efficiency of stem cell transduction. In vivo selection is a strategy for enriching a minor population of genetically modified bone marrow cells through the introduction of a drug resistance gene, followed by subsequent administration of the corresponding cytotoxic drug in vivo. Achieving persistent effects from in vivo selection is expected to require selection at the level of stem cells or, minimally, selection at the level of progenitors. Major limitations to in vivo selection are the nonhematologic toxicities of the cytotoxic drugs used and the resistance of stem cells and progenitors to killing by most cytotoxic agents. Experiments were performed in mice to evaluate whether the drugs used for selection in combination with multiple drug resistance gene 1 (MDR1) could have an enhanced effect on clonogenic progenitors if preceded by administration of the cytokine, stem cell factor (SCF). Single doses of taxol, navelbine, or vinblastine produced 10-fold reductions in the total number of mononuclear cells per femur, indicating a significant depletion of nonclonogenic precursor cells. However, for each of these agents, clonogenic progenitors, assayed as colony-forming unit cells and day-12 spleen colony-forming units, were relatively spared. Administration of SCF before taxol, navelbine, or vinblastine completely abrogated the progenitor-sparing phenomenon, because clonogenic progenitors were depleted as effectively as nonclonogenic precursor cells. Furthermore, the administration of SCF before drug administration allowed the dosages of taxol and vinblastine to be reduced by more than half, while retaining reductions in progenitor numbers that were unachievable using very high doses of the cytotoxic drug alone. Doxorubicin administration resulted in a 30- to 40-fold depletion in progenitors that was not significantly altered by preceding SCF administration. These results suggest that previous observations of in vivo selection using MDR1 gene transfer followed by taxol administration may have resulted from selection at the level of relatively mature, nonclonogenic precursor cells. Furthermore, these data suggest that cytokine prestimulation may be a useful strategy for improving the selection of drug-resistant clonogenic progenitors and, possibly, stem cells in vivo.     

Secondary cellulose acetate hollow nanofiltration fibre

The studies showed that addition of certain amounts of glycerin and PEG to solution causes corresponding changes in structure and allows obtaining hollow fibres with nanofiltration properties. The parameters for spinning a hollow nanofiltration fibre for purification of part of the wastes from production of viscose fibres were developed based on the data obtained.All-Russian Scientific-Research Institute of Polymer Fibres, Mytishchi. Translated from Khimicheskie Volokna, No. 3, pp. 38–43, May–June, 1994.