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91.
A Guhlmann D Brecht-Krauss G Suger G Glatting J Kotzerke L Kinzl SN Reske 《Canadian Metallurgical Quarterly》1998,39(12):2145-2152
The aim of this study was to assess the usefulness of PET with 2-18F-fluoro-2-deoxy-D-glucose (FDG), as compared to immunoscintigraphy (IS) with 99mTc-labeled monoclonal antigranulocyte antibodies (AGAbs), in the detection of chronic osteomyelitis. METHODS: Fifty-one patients suspected of having chronic osteomyelitis in the peripheral (n = 36) or central (n = 15) skeleton were evaluated prospectively with static FDG PET imaging and combined 99mTc-AGAb/99mTc-methylene diphosphonate (MDP) bone scanning within 5 days. FDG PET and IS were evaluated in a blinded and independent manner by visual interpretation, which was graded on a five-point scale of two observers' confident diagnosis of osteomyelitis. Receiver operating characteristic (ROC) curve analysis was performed for both imaging modalities. The final diagnosis was established by means of bacteriologic culture of surgical specimens and histopathologic analysis (n = 31) or by biopsy and clinical follow-up over 2 yr (n = 20). RESULTS: Of 51 patients, 28 had osteomyelitis and 23 did not. According to the unanimous evaluation of both readers, FDG PET correctly identified 27 of the 28 positives and 22 of the 23 negatives (IS identified 15 of 28 positives and 17 of 23 negatives, respectively). The area under the ROC curve was 0.97/0.97 (reader 1/reader 2) for FDG PET and 0.87/0.90 for IS, with a high degree of interobserver concordance (K-values were 0.96 for FDG PET and 0.91 for IS). In the central skeleton, the ROC curve area was 0.98/1.00 for FDG PET and 0.71/0.77 for IS (p<0.05). On the basis of ROC analysis, the overall accuracies of FDG PET and IS in the detection of chronic osteomyelitis were 96%/96% and 82%/ 88%, respectively. With regard to the optimal threshold values, sensitivity and specificity were 100%/97% and 95%/95% with FDG PET, compared to 86%/92% and 77%/82% with IS, respectively. CONCLUSION: In the peripheral skeleton, both FDG PET and combined 99mTc-AGAb/99mTc-MDP scanning are appropriate imaging modalities to diagnose chronic osteomyelitis. FDG PET additionally allows reliable differentiation between osteomyelitis and infection of the surrounding soft tissue. In the central skeleton within active bone marrow, FDG PET is highly accurate and superior to AGAb imaging in the diagnosis of chronic osteomyelitis, which frequently presents as a nonspecific photopenic lesion at scintigraphy with labeled white blood cells. 相似文献
92.
This research is motivated by the co-operative production process of networked manufacturing systems (NMS). Manufacturing resource sharing and flexible production scheduling are two features of NMS. For an individual manufacturing system in an NMS, ‘flexible production scheduling’ means that it can produce multiple product-types and the switching of products is quick enough to respond to the demand fluctuation. ‘Manufacturing resource sharing’ means the utilisation of extra production capacity from other manufacturing systems in the NMS. Of course, that will bring extra cost. This paper focuses on the optimal production control problem of such a situation: one manufacturing system, multiple product-types, and uncertain demands. Here, it is assumed that there are two demand-levels for each product-type: the lower one and the higher one. The total normal production capacity is larger than the total lower demands and smaller than the total higher demands. If the total demands cannot be satisfied and the work-in-process (WIP) of all product-types decrease to a certain level, e.g. zero WIP, the extra production capacity may be utilised. For such a system, a new two-level hedging point policy is proposed, in which two hedging points (a higher one and a lower one) are given for each product-type. Different from the prioritised hedging point (PHP) policy which is usually applied to one-machine and multiple part-type systems, our control policy considers all part-types at the same prioritised level and keeps the work-in-process states of all product-types on a straight line in the state space. Thus, the total costs for WIP inventory and the occupation of extra capacity can be obtained in a closed form, which is a function with respect to the hedging points. Then the method for optimising the hedging points is proposed and the special structure of the optimal hedging point is obtained. Numerical experiments verify the optimality and the special structure of the hedging point obtained by our method. 相似文献
93.
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95.
AL Zakharenko SN Khodyreva NI Rechkunova IV Safronov DV Pyshnyi SK Degtyarev OI Lavrik 《Canadian Metallurgical Quarterly》1998,63(8):929-934
The aim of this study was to evaluate the influence of nicotine on the daily rhythms of heart rate, body temperature and locomotor activity in unrestrained rats by use of implanted radiotelemetry transmitters. The study was divided into three seven-day periods: a control period, a treatment period and a recovery period. The control period was used for baseline measurement of heart rate, body temperature and locomotor activity. During the treatment period three rats received nicotine (1 mg kg(-1), s.c.) at 0900 h. Three rats received saline under the same experimental conditions. Heart rate, body temperature and locomotor activity were continuously monitored and plotted every 10 min. During the three periods a power spectrum analysis was used to determine the dominant period of rhythmicity. If daily rhythms of heart rate, body temperature and locomotor activity were detected, the characteristics of these rhythms, i.e. the mesors, amplitudes and acrophases, were determined by cosinor analysis, expressed as means +/- s.e.m. and compared by analysis of variance. Nicotine did not suppress daily rhythmicity but induced decreases of amplitudes and phase-advances of acrophases for heart rate, body temperature and locomotor activity. These perturbations might result from the effects of nicotine on the suprachiasmatic nucleus, the hypothalamic clock that co-ordinates biological rhythms. 相似文献
96.
SN Merchant ME Ravicz SE Voss WT Peake JJ Rosowski 《Canadian Metallurgical Quarterly》1998,112(8):715-731
A review of the structure-function relationships in normal, diseased and reconstructed middle ears is presented. Variables used to describe the system are sound pressure, volume velocity and acoustic impedance. We discuss the following: (1) Sound can be transmitted from the ear canal to the cochlea via two mechanisms: the tympanoossicular system (ossicular coupling) and direct acoustic stimulation of the oval and round windows (acoustic coupling). In the normal ear, middle-ear pressure gain, which is the result of ossicular coupling, is frequency-dependent and smaller than generally believed. Acoustic coupling is negligibly small in normal ears, but can play a significant role in some diseased and reconstructed ears. (2) The severity of conductive hearing loss due to middle-ear disease or after tympanoplasty surgery can be predicted by the degree to which ossicular coupling, acoustic coupling, and stapes-cochlear input impedance are compromised. Such analyses are used to explain the air-bone gaps associated with lesions such as ossicular interruption, ossicular fixation and tympanic membrane perforation. (3) With type IV and V tympanoplasty, hearing is determined solely by acoustic coupling. A quantitative analysis of structure-function relationships can both explain the wide range of observed post-operative hearing results and suggest surgical guidelines in order to optimize the post-operative results. (4) In tympanoplasty types I, II and III, the hearing result depends on the efficacy of the reconstructed tympanic membrane, the efficacy of the reconstructed ossicular chain and adequacy of middle-ear aeration. Currently, our knowledge of the mechanics of these three factors is incomplete. The mechanics of mastoidectomy and stapedectomy are also discussed. 相似文献
97.
S Mahanty SN Mollis M Ravichandran JS Abrams V Kumaraswami K Jayaraman EA Ottesen TB Nutman 《Canadian Metallurgical Quarterly》1996,173(3):769-773
To determine whether counterregulation by interleukin (IL)-10 plays a role in the generation or maintenance of the antigen-specific hyporesponsiveness seen in asymptomatic microfilaremic (MF) patients, parasite antigen (PAg)- and nonparasite antigen (NPAg)-driven IL-10 production by peripheral blood mononuclear cells (PBMC) was studied in 10 MF patients and in ll patients with chronic lymphatic pathology (CP). PBMC from MF patients spontaneously secreted 10-fold more IL-10 than did PBMC from patients with CP. PAg also induced significantly more IL-10 production by PBMC from CP patients. There was a negative correlation between PAg driven IL-10 production by PBMC and PAg-specific T cell proliferation in the MF group. IL-10 secretion by plastic adherent cells from MF persons was higher in response to PAg than NPAg, whereas IL-6 and tumor necrosis factor-alpha secretion were equivalent for PAg and NPAg, suggesting that PAg preferentially induces IL-10 secretion in these cells. Thus, PAg-induced IL-10 likely plays an important role in down-regulating antigen-specific proliferative responses in MF patients. 相似文献
98.
Parental illness can have a profound impact on family relationships and children's behaviour. The amount and nature of communication between parents and children about the illness can play an important role, both positively and negatively, in mediating the outcomes. When children have a disability, families can be reluctant to communicate with them about family difficulties. They are often concerned about the impact that parental unavailability may have on their child's life. This paper reports on three families in which the mother was diagnosed with breast cancer and one child in the family had a disability. The extent and specific characteristics of their communication about the maternal illness with their children, behavioural changes in the children, explanations of communication strategies and attributions of behavioural changes are described. Family coping strategies are examined with reference to Lazarus's process model of stress and coping and the use of either problem-focused or emotion-focused strategies. Implications for possible clinical interventions are proposed. In particular it is suggested that families be offered consultation about: what children might understand; ways in which to communicate effectively; and strategies for coping with the long-term implications of serious parental illness. 相似文献
99.
The Ca2+ channel beta subunit has been shown to reduce the magnitude of G-protein inhibition of Ca2+ channels. However, neither the specificity of this action to different forms of G-protein inhibition nor the mechanism underlying this reduction in response is known. We have reported previously that coexpression of the Ca2+ channel beta3 subunit causes M2 muscarinic receptor-mediated inhibition of alpha1B Ca2+ currents to become more voltage-dependent. We report here that the beta3 subunit increases the rate of relief of inhibition produced by a depolarizing prepulse and also shifts the voltage dependency of this relief to more hyperpolarized voltages; these effects are likely to be responsible for the reduction of inhibitory response of alpha1B channels to G-protein-mediated inhibition seen after coexpression of the Ca2+ channel beta3 subunit. Additionally, the beta3 subunit alters the rate and voltage dependency of relief of the inhibition produced by coexpressed Gbeta1gamma1, in a manner similar to the changes it produces in relief of M2 receptor-induced inhibition. We conclude that the Ca2+ channel beta3 subunit reduces the magnitude of G-protein inhibition of alpha1B Ca2+ channels by enhancing the rate of dissociation of the G-protein betagamma subunit from the Ca2+ channel alpha1B subunit. 相似文献
100.
MG Volovik EG Gabdullina AV Zeveke IIa Kle?nbok SN Kolesov SA Polevaia IV Snezhnitskaia 《Canadian Metallurgical Quarterly》1998,84(3):256-259
The ETV6 (TEL) locus at chromosome band 12p 13 is a major site of translocations in acute leukemia, particularly in childhood acute lymphoblastic leukemia (ALL). In cases with translocations involving ETV6, the normal ETV6 allele is often deleted. In addition, loss of heterozygosity of ETV6 is frequently observed in childhood'ALL. Thus, it has been suggested that ETV6 may have an anti-oncogenic role to play, in addition to its oncogenic role. We have described an unusual case of ALL in which ETV6 is found fused to the ABL gene; ABL is normally activated by fusion to the BCR gene in the 9:22 translocation. We expanded the primary cells from this ETV6/ABL rearranged case of ALL in SCID animals and analyzed them for expression of both ETV6/ABL and the normal ETV6 mRNA. We found that both the rearranged and normal ETV6 mRNAs are expressed in the expanded cell population. Furthermore, sequence analysis of the ETV6 PCR product revealed no point mutations which would influence the amino acid sequence. Thus, deletion of the second ETV6 allele is not necessary for the transformation to leukemia by ETV6/ABL. 相似文献