BR Moed  N Thorderson  MD Linden 《Canadian Metallurgical Quarterly》1998,(346):223-227

Patients requiring cancellous bone grafting of an extensive deficit or multiple bone grafting procedures often lack a sufficient quantity of autogenous cancellous bone. Canine studies have indicated that a potential exists for reharvesting autogenous cancellous bone from an iliac crest donor site using a trapdoor harvesting technique. However, significant human experience with this procedure has been lacking. This report describes four patients who underwent successful reharvesting of an iliac crest donor site that provided clinically sufficient autogenous cancellous bone graft material to treat an ongoing or a new skeletal problem. These patients all met specific criteria regarding use of the trapdoor method of bone graft harvest and a minimum 24-month interval between bone grafting procedures. Preoperative computed tomography scanning of the iliac crest was useful in documenting that sufficient cancellous bone was available for reharvest. It appears that iliac crest donor site reharvesting is a specific advantage of the trapdoor technique and is a possible alternative to multiple site grafting or the use of allograft or bone substitute materials.  相似文献   

    

D Rosenthal  CP Atkins  HS Jerrius  MD Clark  JH Matsuura 《Canadian Metallurgical Quarterly》1998,12(1):86-87

Tuberculosis of the breast is a rare disease. Tubercular abscesses predominantly affecting the soft tissues are also very infrequent. A case of chest wall tuberculosis secondarily involving the breast presenting as a hard, fixed lump simulating mammary carcinoma is presented here. There was no evidence of pleural or pulmonary tuberculosis.  相似文献   

    

DY Sze  RC Robbins  CP Semba  MK Razavi  MD Dake 《Canadian Metallurgical Quarterly》1998,116(2):253-261

The aims of this study were to establish a working rabbit heart model of regional myocardial ischaemia in which electrophysiologic parameters and arrhythmogenesis could be correlated and to explore the mechanisms underlying the antiarrhythmic activity of lignocaine. Monophasic action-potential duration (MAPD90), effective refractory period (ERP), and conduction delay were measured at three ventricular sites in isolated hearts paced at 3.3 Hz. The hearts were treated before and throughout 30 min of ischaemia and 15 min of reperfusion with a vehicle or 20 microM lignocaine. In both groups, ischaemia produced a similar shortening in MAPD90. Lignocaine decreased ERP shortening during ischaemia from -56+/-4 to -32+/-6 ms. An ischaemia-induced increase in conduction delay was greater in the lignocaine than the control group (49+/-7 vs. 11+/-2 ms). Ischaemia-induced dispersion of repolarisation was reduced by lignocaine from 66+/-4 to 32+/-7 ms, and dispersion of refractoriness was decreased from 57+/-6 to 16+/-3 ms. Lignocaine decreased inducibility of ventricular fibrillation (VF) during ischaemia from 86 to 25%. We conclude that, in this model, the antiarrhythmic activity of lignocaine during regional ischaemia is associated with an increase in ischaemia-induced conduction delay and reduced dispersion of repolarisation and refractoriness.  相似文献   

    

MD Henry  C Gonzalez Agosti  F Solomon 《Canadian Metallurgical Quarterly》1995,129(4):1007-1022

The ERM proteins--ezrin, radixin, and moesin--occur in particular cortical cytoskeletal structures. Several lines of evidence suggest that they interact with both cytoskeletal elements and plasma membrane components. Here we described the properties of full-length and truncated radixin polypeptides expressed in transfected cells. In stable transfectants, exogenous full-length radixin behaves much like endogenous ERM proteins, localizing to the same cortical structures. However, the presence of full-length radixin or its carboxy-terminal domain in cortical structures correlates with greatly diminished staining of endogenous moesin in those structures, suggesting that radixin and moesin compete for a limiting factor required for normal associations in the cell. The results also reveal distinct roles for the amino- and carboxy-terminal domains. At low levels relative to endogenous radixin, the carboxy-terminal polypeptide is associated with most of the correct cortical targets except cleavage furrows. In contrast, the amino-terminal polypeptide is diffusely localized throughout the cell. Low level expression of full-length radixin or either of the truncated polypeptides has no detectable effect on cell physiology. However, high level expression of the carboxy-terminal domain dramatically disrupts normal cytoskeletal structures and functions. At these high levels, the amino-terminal polypeptide does localize to cortical structures, but does not affect the cells. We conclude that the behavior of radixin in cells depends upon activities contributed by separate domains of the protein, but also requires modulating interactions between those domains.  相似文献   

  总被引：2，自引：0，他引：2  

MD Adams  DZ Rudner  DC Rio 《Canadian Metallurgical Quarterly》1996,8(3):331-339

During the past year, significant advances have been made in the field of pre-mRNA splicing. It is now clear that members of the serine-arginine-rich protein family are key players in exon definition and function at multiple steps in the spliceosome cycle. Novel findings have been made concerning the role of exon sequences, which function as both constitutive and regulated enhancers of splicing, in trans-splicing and as targets for tissue-specific control of splicing patterns. By combining biochemical approaches in human and yeast extracts with genetic analysis, much has been learned about the RNA-RNA and RNA-protein interactions that are necessary to assemble the various complexes that are found along the pathway to the catalytically active spliceosome.  相似文献   

    

G Todd  K Dunlop  J McNaboe  MF Ryan  D Carson  MD Shields 《Canadian Metallurgical Quarterly》1996,348(9019):27-29

BACKGROUND: Fluticasone propionate was introduced in 1993 in the UK as a potentially safer inhaled corticosteroid than those already in use. The efficacy and safety of fluticasone has been established at recommended doses of 200 micrograms/day, but not at higher doses that are often used. METHODS: Growth retardation was observed in six severely asthmatic children after introduction of high-dose fluticasone propionate treatment (dry powder). Assessment of cortisol response was by insulin-induced hypoglycaemia in three cases, by short tetracosactrin test in two, and by low-dose tetracosactrin and 24-hour urinary cortisol/creatinine ratio in one. FINDINGS: Six children with growth retardation noted after treatment with high-dose fluticasone propionate were found to have adrenal suppression. In one case the growth rate and cortisol response returned to normal 9 months after the fluticasone dose was reduced to 500 micrograms/day. INTERPRETATION: When high doses of fluticasone propionate are used, growth may be retarded and adrenal suppression may occur.  相似文献   

    

MD Brennan  PA Thorpe  J Hu  WJ Dickinson 《Canadian Metallurgical Quarterly》1996,181(1-2):51-55

A total of 71 Staphylococcus aureus strains isolated from bovine mammary glands were identified and subtyped. The methods used to differentiate between the S. aureus isolates were the DNA polymorphism pattern after amplification with a Polymerase Chain Reaction using several primer combinations and phage typing. The DNA fingerprinting technique using RAPD, ERIC1R and ERIC primers proved to be useful in differentiating isolates of S. aureus. Differentiation of isolates using phage typing gave no additional information compared to the DNA technique. The outbreak of S. aureus in the herd studied was mainly caused by one S. aureus strain. Other strains were only found on three occasions, twice in subclinical infections and once from a case of clinical mastitis. In the latter case the dominant strain was isolated from a different quarter of the same cow. Four of the ten cows studied suffered from clinical mastitis. From those four cows, three remained infected with the same S. aureus strain despite antibiotic treatment.  相似文献   

    

D Becker  Y Razskazovskii  MU Callaghan  MD Sevilla 《Canadian Metallurgical Quarterly》1996,146(4):361-368

A major problem in the intensive care unit nowadays is the development of multiple organ dysfunction syndrome (MODS), a cumulative sequence of progressive deterioration of organ functions. While the pathogenic pathways of MODS remain to be elucidated, it is assumed that cells of the host defence system, especially the macrophages, are altered in their function. During the development of MODS it is assumed that macrophages are overactivated and that an exaggerated inflammatory response may contribute to its pathogenesis. In order to gain insight into the alterations of the functional status of the macrophage during the development of MODS, a series of macrophage functions was measured in the subsequent phases of zymosan induced generalized inflammation in mice. Male C57BL/6 mice received a single dose of zymosan intraperitoneally and groups of animals were killed after 2, 5, 8, and 12 days. Peritoneal macrophages were collected for in vitro assessment of the ADCC, the production of superoxide (O2-) and nitric oxide (NO), and complement mediated phagocytosis and intracellular killing of Staphylococcus aureus. A single intraperitoneal injection with zymosan resulted in a three-phase illness. During the third phase the animals developed MODS-like symptoms. Peritoneal cells from control animals produced very low to non-detectable amounts of O2- and NO, and the cytotoxic activity was also low. During the development of MODS, from day 7 onwards, the ability to produce O2- and NO2- became strongly elevated, as did the cytotoxic activity. These findings are in parallel with the development of MODS whereas the phagocytic and killing capacity remained essentially unaltered. The changes found could be detrimental for the organism, thus possibly contributing to the onset and development of MODS.  相似文献   

    

DE Chadwick  LF Jean  N Jamal  HA Messner  JR Murphy  MD Minden 《Canadian Metallurgical Quarterly》1993,85(1):25-36

The cytotoxicity of a recombinant interleukin 6 (IL-6)-diphtheria toxin (DT) fusion protein towards human myeloma cell lines was investigated. DAB389-IL-6 inhibited protein synthesis and methylcellulose colony formation by U266 myeloma cells. In the clonogenic assay, the fusion protein approached the level of cytotoxicity achieved by native DT. The specificity of killing by DAB389-IL-6 was demonstrated by inhibition of cytotoxicity by a molar excess of free rhIL-6. The effect of DAB389-IL-6 on colony formation by six OCI-My cell lines was assessed. Similar to U266 cells, colony growth by the OCI-My 5 and -My 2 cell lines was inhibited in a simple dose dependent manner. However, a biphasic effect was observed for the IL-6 dependent OCI-My 4 cells; DAB389-IL-6 stimulated colony formation at low (< or = 10(-11) M) concentrations, yet was inhibitory at higher doses. Three other cell lines whose growth was not altered by IL-6 were relatively unaffected by DAB389-IL-6, despite their sensitivity to native DT. Flow cytometric analysis for IL-6 receptor expression using phycoerythrin-conjugated IL-6 demonstrated specific binding sites on both DAB389-IL-6 sensitive and certain insensitive cell lines, suggesting that other factors in addition to the expression of IL-6 receptors are involved in killing by the fusion toxin. Despite evidence for a role of IL-6 in myeloid cell development, normal bone marrow was insensitive to the IL-6 fusion toxin. In cultures containing both normal bone marrow and U266 cells DAB389-IL-6 effectively inhibited the growth of U266 myeloma colonies but had little effect on normal bone marrow erythroid, granulocyte and mixed erythroid/granulocyte colony growth. From these experiments we conclude that DAB389-IL-6 is specifically cytotoxic towards a subset of IL-6-responsive human myeloma cell lines and may be useful, in some cases, in the selective elimination of tumour cells from mixed populations of normal and malignant cells.  相似文献   

    

Q Du  MD Gunzburger  JS Peterson 《Canadian Metallurgical Quarterly》1995,51(22):16194-16203

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