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151.
Between 1974 and 1989 we prospectively observed 530 patients with brucellosis. The findings for 62 patients (42 males and 20 females; mean age, 34.7 years) with 63 episodes in which the sacroiliac joint was involved (the most frequent osteoarticular location [11.7%]) were analyzed. Ten of the older patients (mean age, 55.3 years) had concomitant spondylitis. Systemic symptoms were usually important, and characteristic pain and findings of sacroiliitis were observed in approximately 75% of cases. Blood cultures were positive for Brucella melitensis for 44 patients. The most frequent radiographic findings were blurring of articular margins (42 cases) and widening of the sacroiliac space (20 cases). No radiographic anomalies were detected in 13 cases. Results of 99mTc and gallium-67 bone scans were abnormal in approximately 90% of cases (abnormalities were often mild). Overall, clinical, radiographic, and isotopic bone scan findings were sensitive and useful, although they were occasionally minimal or difficult to evaluate, making diagnostic findings confusing or misleading. Brucellar sacroiliitis is a mild disease associated with a good outcome similar to that observed for patients with uncomplicated brucellosis.  相似文献   
152.
153.
The optimal field shape achieved using a multileaf collimator (MLC) often requires collimator rotation to minimize the adverse effects of the scalloped dose distribution the leaf steps produce. However, treatment machines are designed to deliver wedged fields parallel or perpendicular to the direction of the leaves. An analysis of cases from our clinic showed that for 25% of the wedged fields used to treat brain and lung tumors, the wedge direction and optimal MLC orientation differed by 20 degrees or more. The recently published omni wedge technique provides the capability of producing a wedged field with orientation independent of the orientation of the collimator. This paper presents a comparison of the three-dimensional (3D) dose distributions of the omni wedged field with distributions of wedged fields produced using both the universal and dynamic wedge techniques. All measurements were performed using film dosimetry techniques. The omni wedge generated fields closely matched the conventional wedged fields. Throughout 95% of the irradiated volume (excluding the penubra), the dose distribution of the omni wedged field ranged from +5.5 to -3.5 +/- 1.5% of that of the conventionally wedged fields. Calculation of the omni wedged field is as accurate as conventional wedged field calculation when using a 3D treatment planning systems. For two-dimensional treatment planning systems, where one must assume that the omni wedged field is identical to a conventional field, the calculated field and the delivered field differs by a small amount.  相似文献   
154.
A new method for preparing poly(L-lactide) (PLA) biodegradable beads impregnated with an ionic aminoglycoside, gentamycin, is described. The process employs hydrophobic ion pairing to solubilize gentamycin in a solvent compatible with PLA, followed by precipitation with a compressed antisolvent (supercritical carbon dioxide). The resulting precipitate is a homogeneous dispersion of the ion-paired drug in PLA microspheres. The microspheres are approximately 1 microm in diameter and can be compressed into beads (3-6 mm in diameter) strung on surgical sutures for implantation. The bead strings exhibit no significant change in release kinetics upon sterilization with a hydrogen peroxide plasma (Ster-Rad). The kinetics of gentamycin release from the PLA beads are consistent with a matrix-controlled diffusion mechanism. While nonbiodegradable poly(methyl methacrylate) (PMMA) beads initially release gentamycin in a similar manner, the drug release from PMMA ceases after 8 or 9 weeks, while the PLA beads continue to release drug for over 4 months. Moreover, only 10% of the gentamycin is released from the PMMA beads, while PLA beads release more than 60% of their load, if serum is present in the release medium. The PLA system displays improved release kinetics relative to PMMA, is biodegradable, is unaltered by gas sterilization, can be used for a range of antibiotics, and can be manipulated without disintegration. These are all desirable properties for an implantable drug delivery system for the prevention or treatment of osteomyelitis.  相似文献   
155.
Pancreatic ductal adenocarcinoma is one of the major causes of cancer mortality in the industrialized world, having among the poorest prognosis of any malignancy. Mutations or alterations in the p53 tumor suppressor gene/protein are observed in 50-70% of these cancers, yet little information is available regarding the phenotypic effects of restoration of wild-type (wt) p53 function in pancreatic ductal carcinoma cells. The consequences of stable reintroduction of wt p53 on apoptosis and differentiation was examined in a poorly differentiated pancreatic carcinoma cell line (Panc-1), possessing only mutant (mt) p53 (codon 273 mutation). Cells were transfected with a temperature-sensitive mouse p53val135 (tsp53) vector under additional control of a genetically-modified metallothionein promoter. This tsp53 has a 'mt' phenotype at 37.5 degrees C, and a 'wt' phenotype at 32.5 degrees C and the presence of 100 microM ZnCl2. Stable expression of wt p53 caused upregulation of the p21/WAF1 gene, and G1 growth arrest as shown by flow cytometry and BrdU labeling. Additionally, apoptosis was induced 8-12 post-induction in the majority of the cells (60-70%), as demonstrated by morphological changes, in situ TdT labeling and internucleosomal laddering. However, a subpopulation (30%) of the transfectants survived this apoptotic fate. Unlike the epithelial parental Panc-1 cells, these cells exhibited the appearance of a neuroendocrine-like phenotype with extensive branch-like processes, and marked cytoplasmic and cytoskeletal immunostaining for tau-2, synaptophysin, and chromogranin A. These studies suggest that stable and regulated expression of wt p53 can have multiple phenotypic consequences (apoptosis and altered differentiation to a neuroendocrine-like phenotype) in poorly-differentiated pancreatic carcinoma cells.  相似文献   
156.
Impaired exercise capacity is a common finding in chronic obstructive pulmonary disease (COPD) patients. This reduction is not a simple consequence of airflow limitation. Peripheral muscle weakness, deconditioning and impaired gas exchange, were recognized as important contributors to exercise intolerance. In this overview, the contribution of peripheral muscle function and muscle training to exercise performance is discussed by means of three questions: 1) Is peripheral muscle dysfunction contributing to exercise limitation in COPD? 2) How do we measure peripheral muscle function? 3) Are peripheral muscle training modalities effective? At present, there is substantial evidence for peripheral muscle dysfunction. Both reduced force generating capacity as well as impaired muscle metabolism were observed and these findings contributed substantially to the reduced exercise capacity in COPD. Peripheral muscle strength measurements are feasible with mechanical or electronic devices and revealed muscle weakness in COPD patients. However, this weakness is not uniform for all muscle groups. Upper arm and leg muscles were more affected than hand muscles. This may, at least in part, be related to differences in the levels of inactivity between leg and hand muscles. In addition, muscle weakness is associated with impaired exercise capacity and symptoms of increased exertion during exercise. Endurance exercise training, i.e. cycling and treadmill walking, improved exercise capacity and was associated with alterations in muscle metabolism. Strength training of peripheral muscles showed increases in submaximal exercise performance and quality of life measures. These improvements were observed independently of the degree of airflow obstruction. The optimal training regimen (strength or endurance), and the muscle groups to be trained, remain to be determined.  相似文献   
157.
PURPOSE: Lym-1, a monoclonal antibody that preferentially targets malignant lymphocytes, has induced remissions in patients with non-Hodgkin's lymphoma (NHL) when labeled with iodine 131 ((131)I). Based on the strategy of fractionating the total dose, this study was designed to define the maximum-tolerated dose (MTD) and efficacy of the first two, of a maximum of four, doses of (131)I-Lym-1 given 4 weeks apart. Additionally, toxicity and radiation dosimetry were assessed. MATERIALS AND METHODS: Twenty patients with advanced NHL entered the study a total of 21 times. Thirteen (62%) of the 21 entries had diffuse large-cell histologies. All patients had disease resistant to standard therapy and had received a mean of four chemotherapy regimens. (131)I-Lym-1 was given after Lym-1 and (131)I was escalated in cohorts of patients from 40 to 100 mCi (1.5 to 3.7 GBq)/m2 body surface area. RESULTS: Mean radiation dose to the bone marrow from body and blood (131)I was 0.34 (range, 0. 1 6 to 0.63) rad/mCi (0.09 mGy/MBq; range, 0.04 to 0.17 mGy/ MBq). Dose-limiting toxicity was grade 3 to 4 thrombocytopenia with an MTD of 100 mCi/m2 (3.7 GBq/m2) for each of the first two doses of (131)I-Lym-1 given 4 weeks apart. Nonhematologic toxicities did not exceed grade 2 except for one instance of grade 3 hypotension. Ten (71 %) of 14 entries who received at least two doses of (131)I-Lym-1 therapy and 11 (52%) of 21 total entries responded. Seven of the responses were complete, with a mean duration of 14 months. All three entries in the 100 mCi/m2 (3.7 MBq/m2) cohort had complete remissions (CRs). All responders had at least a partial remission (PR) after the first therapy dose of (131)I-Lym-1. CONCLUSION: (131)I-Lym-1 induced durable remissions in patients with NHL resistant to chemotherapy and was associated with acceptable toxicity. The nonmyeloablative MTD for each of the first two doses of (131)I-Lym-1 was 100 mCi/m2 (total, 200 mCi/m2) (3.7 GBq/m2; total, 7.4 GBq/m2).  相似文献   
158.
The MEN1 gene, mutations in which are responsible for multiple endocrine neoplasia type 1 (MEN1), encodes a 610-amino acid protein, denoted menin. The amino acid sequence of this putative tumor suppressor offers no clue to the function or subcellular location of the protein. We report herein, based on immunofluorescence, Western blotting of subcellular fractions, and epitope tagging with enhanced green fluorescent protein, that menin is located primarily in the nucleus. Enhanced green fluorescent protein-tagged menin deletion constructs identify at least two independent nuclear localization signals (NLS), both located in the C-terminal fourth of the protein. Among the 68 known independent disease-associated mutations, none of the 22 missense and 3 in-frame deletions affect either of the putative NLS sequences. However, if expressed, none of the truncated menin proteins resulting from the 43 known frameshift/nonsense mutations would retain both the NLSs. The precise role(s) of menin in the nucleus remain to be understood.  相似文献   
159.
Recent blood pressure trends reflect progress in hypertension control, but prevalent drug therapy precludes direct estimation of the component due to primary prevention. In data gathered on persons aged 35-74 years in three successive US health examination surveys (1960-1980), systolic blood pressure levels assuming no drug therapy were imputed by reassigning blood pressure to the upper end of the distribution for respondents reporting use of antihypertensive medication. Blood pressure was partitioned into four ordinal categories based on weighted percentiles of the 1960-1962 distributions for 35- to 44-year-old males and females who reported no use of antihypertensive medication. Cumulative logit models (alpha = 0.01) were used to estimate age- and sex-specific trends for blacks and whites within two strata (<25 or > or =25) of body mass index (BMI) (weight (kg)/height (m)2). Before imputation, systolic blood pressure decreased between 1960 and 1980; after imputation, significant decreases remained only in 35- to 44-year-olds. Strong associations of black race and BMI > or =25 with higher blood pressures were present in models with and without drug therapy. Thus, according to the models, there has been little progress in decreasing racial or BMI-related blood pressure differentials. Above the age of 44 years, blood pressure trends were largely attributable to medication use. In contrast, data for 35- to 44-year-olds suggest progress in primary prevention.  相似文献   
160.
A new subgroup of avian leukosis virus (ALV) that includes a unique env gene, designated J, was identified recently in England. Sequence analysis of prototype English isolate HPRS-103 revealed several other unique genetic characteristics of this strain and provided information that it arose by recombination between exogenous and endogenous virus sequences. In the past several years, ALV J type viruses (ALV-J) have been isolated from broiler breeder flocks in the United States. We were interested in determining the relationship between the U.S. and English isolates of ALV-J. Based on sequence data from two independently derived U.S. field isolates, we conclude that the U.S. and English isolates of ALV-J derive from a common ancestor and are not the result of independent recombination events.  相似文献   
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