Lateral meniscal cyst. Retrospective study of 105 cysts treated with arthroscopy with 5 year follow-up

PURPOSE: To investigate possible functional correlates of an apparent ON-pathway defect observed in the cone electroretinogram of a patient with acquired unilateral night blindness. METHOD: Visual evoked potentials were recorded to the onset of a grid pattern consisting of either incremental or decremental squares. Saccadic eye movements were measured to luminance increments and decrements presented 5 degrees from fixation. The patient's results were compared with normative data. RESULTS: Visual evoked potential latencies were prolonged to incremental stimulation of the patient's affected left eye but were within normal limits for the other three conditions (increments and decrements, right eye; decrements, left eye). A similar pattern of asymmetry between latencies to incremental and decremental stimulation of the affected eye was observed for saccadic eye movements. CONCLUSIONS: The observed predominant delay in response to luminance increments supports the hypothesis of an ON-pathway dysfunction in this patient with acquired unilateral night blindness.     

Serum erythropoietin in chronic lymphocytic leukaemia

OBJECTIVE: To establish whether there is any improvement in pregnancy and implantation rates after administration of "low-dose," long-acting glucocorticoids during transfer of cryopreserved-thawed embryos. SETTING: An IVF unit in a university hospital. DESIGN: Prospective, randomized study. Ninety-nine consecutive transfer cycles of frozen-thawed embryos to the uterine cavity of randomly chosen women diagnosed as having tubal factor infertility only. Fifty-two patients underwent transfer of frozen-thawed embryos and received 0.5 mg of dexamethasone; 47 women (control group) did not receive the drug during transfer. PATIENTS: Normal ovulatory patients with tubal factor infertility. INTERVENTIONS: Oral dexamethasone administration before, during and after transfer of thawed embryos. MAIN OUTCOME MEASURES: Pregnancy and implantation rates. RESULTS: The pregnancy rate was 13.5% (7/52) in patients treated with the "low-dose" regimen of dexamethasone compared with 12.8% (6/47) in the control group. The implantation rate was similar. CONCLUSION: Our results demonstrated that the use of 0.5 mg dexamethasone for an immuno-suppressive effect, administered for a short period to patients diagnosed as having "pure" tubal factor infertility, did not improve the implantation or pregnancy rates.     

Instrument mediated activity: from subject development to anthropocentric design

The aim of this article is to present the ‘instrument-mediated activity’ approach, which is part of a ‘generative model’. A group of principles liable to contribute to the epistemological unity of generative models is put forward as well as a theoretical framework that conceptualizes what an instrument is for the subject. The article develops the idea that the instrument is a mixed entity born of both the subject and the artifact. The artifact is not an instrument in itself. It is the subject who grants it the status of a means for his/her action. Processes of design in usage by users are defined as ‘instrumental geneses’. Finally, the consequences of this model on the organization of design processes are examined, in taking into account instrumental geneses as resources for design.     

Red blood cell precursor mass as an independent determinant of serum erythropoietin level

Serum erythropoietin (sEpo) concentration is primarily related to the rate of renal production and, under the stimulus of hypoxia, increases exponentially as hemoglobin (Hb) decreases. Additional factors, however, appear to influence sEpo, and in this work, we performed studies to evaluate the role of the red blood cell precursor mass. We first compared the relationship of sEpo with Hb in patients with low versus high erythroid activity. The first group included 27 patients with erythroid aplasia or hypoplasia having serum transferrin receptor (sTfR) levels < 3 mg/L (erythroid activity < 0.6 times normal), while the second one included 28 patients with beta-thalassemia intermedia having sTfR levels > 10 mg/L (erythroid activity > 2 times normal). There was no difference between the two groups with respect to Hb (8.3 +/- 1.6 v 8.0 +/- 1.3 g/dL, P > .05), but sEpo levels were notably higher in patients with low erythroid activity (1,601 +/- 1,542 v 235 +/- 143 mU/mL, P < . 001). In fact, multivariate analysis of variance (ANOVA) showed that, at any given Hb level, sEpo was higher in patients with low erythroid activity (P < .0001). Twenty patients undergoing allogeneic or autologous bone marrow transplantation (BMT) were then investigated. A marked increase in sEpo was seen in all cases at the time of marrow aplasia, disproportionately high when compared with the small decrease in Hb level. Sequential studies were also performed in five patients with iron deficiency anemia undergoing intravenous (IV) iron therapy. Within 24 to 72 hours after starting iron treatment, marked decreases in sEpo (up to one log magnitude) were found before any change in Hb level. Similar observations were made in patients with megaloblastic anemia and in a case of pure red blood cell aplasia. These findings point to an inverse relationship between red blood cell precursor mass and sEpo: at any given Hb level, the higher the number of red blood cell precursors, the lower the sEpo concentration. The most likely explanation for this is that sEpo levels are regulated not only by the rate of renal production, but also by the rate of utilization by erythroid cells.     

Mechanical and barrier properties of MOCVD processed alumina coatings on Ti6Al4V titanium alloy

This study focuses on the implementation of different aluminum oxide coatings processed by metal-organic chemical vapor deposition from aluminum tri-isopropoxide on commercial Ti6Al4V titanium alloy to improve its high temperature corrosion resistance. Films grown at 350 °C and at 480 °C are amorphous and correspond to formulas AlOOH, and Al₂O₃, respectively. Those deposited at 700 °C are composed of γ-Al₂O₃ nanocrystals dispersed in a matrix of amorphous alumina. Their mechanical properties and adhesion to the substrates were investigated by indentation, scratch and micro tensile tests. Hardness and rigidity of the films increase with increasing deposition temperature. The hardness of the coatings prepared at 350 °C and 480 °C is 5.8 ± 0.7 GPa and 10.8 ± 0.8 GPa respectively. Their Young's modulus is 92 ± 8 GPa (350 °C) and 155 ± 6 GPa (480 °C). Scratch tests cause adhesive failures of the films grown at 350 °C and 480 °C whereas cohesive failure is observed for the nanocrystalline one, grown at 700 °C. Micro tensile tests show a more progressive cracking of the latter films than on the amorphous ones. The films allow maintaining good mechanical properties after corrosion with NaCl deposit during 100 h at 450 °C. After corrosion test only the film deposited at 700 °C yields an elongation at break comparable to that of the as processed samples without corrosion. The as established processing–structure–properties relation paves the way to engineer MOCVD aluminum oxide complex coatings which meet the specifications of the high temperature corrosion protection of titanium alloys with regard to the targeted applications.     

Systematic analysis of in-patients' circumstances and causes of death: a tool to improve quality of care

OBJECTIVES: To point out actions improving quality of care from a systematic analysis of causes and circumstances of death of hospital patients. DESIGN: All in-hospital patient deaths during 1993 and 1994. SETTING: Saint Luc University hospital. MAIN OUTCOME MEASURES: Immediate and original causes of death, other diagnoses or procedures, circumstances of death, place, members of hospital staff, family or friends with the patient, mention of "do not resuscitate", of unexpected death, of problems during the process of care and of autopsy performed. RESULTS: The mean age of the patients was 60 years. The proportion of men was 57%. The majority of patients died in their room. No family or friends, or members of hospital staff were observed for 17%. "Do no resuscitate" was mentioned for 38% of the patients and the proportion of unexpected death and autopsy was 15% and 28% respectively. The most frequent causes of death were malignant and cardiovascular diseases. At least one of the following diseases was mentioned on 14% of the forms; complications during care, septicaemia, pulmonary embolism, adverse effects of drugs or pressure ulcer. Mean length of hospital stay was 14.7 days. CONCLUSIONS: A systematic analysis of the causes and circumstances of death reveals the epidemiology of hospital deaths and highlights specific diseases, complications or circumstances that could be changed. This study creates the opportunity for possible further action, such as improvement in prevention of pulmonary embolism and support of the members of staff or the friends and family of the patient at the time of death.     

Prediction of response to recombinant human erythropoietin (rHuEpo) in anemia of malignancy

BACKGROUND: Since only a portion of anemic patients outside the uremia setting benefit from erythropoietin treatment, a reliable means of predicting potential responders and nonresponders would be very useful. MATERIALS AND METHODS: We retrospectively reviewed the clinical records of 58 patients with refractory anemia associated with various malignant disorders who had been treated with subcutaneous rHuEpo. The starting rHuEpo dose was 375 U/kg/week for 4 weeks, and was increased to 750 U/kg/week for another 4 weeks if no response was observed. Response was defined as a Hb increase > or = 2 g/dL with no need for blood transfusion. We examined the value of various laboratory parameters (baseline levels, 2-week and 4-week changes) as predictors of response. Endogenous erythropoietin production was evaluated by its serum level and erythroid activity was assessed through reticulocyte count and circulating transferrin receptor. RESULTS: Forty-eight individuals were evaluable, 58% of whom responded to rHuEpo within 8 weeks. Multiple regression analysis showed that 53% of the variation in the 8-week Hb concentration was explained by variations in baseline serum erythropoietin and the 2-week change in serum transferrin receptor (p < 0.001). Based on these two parameters, response prediction in individual patients would have resulted in a sensitivity of 96%, a specificity of 79% and an overall accuracy of 88%. In addition, 58% of the variation in the 8-week Hb was explained by variations in the 4-week changes in Hb and reticulocyte count (p < 0.001). Utilizing these latter parameters and baseline serum erythropoietin, response prediction in individual patients would have resulted in a sensitivity of 92%, a specificity of 82% and an overall accuracy of 88%. CONCLUSIONS: This retrospective analysis suggests that response to rHuEpo can be reasonably predicted by pretreatment serum erythropoietin together with early changes in simple laboratory parameters.     

Fabrication and performance of low loss optical components made byion exchange in glass

Passive optical components made by photolithography with ion exchange in glass have been developed. The technology used to fabricate these components is described, and their performance characterization is discussed. It is shown that this technique produces highly uniform low-loss devices