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51.
An osteopenic nonfracture syndrome with features of mild osteogenesis imperfecta associated with the substitution of a cysteine for glycine at triple helix position 43 in the pro alpha 1(I) chain of type I collagen. 总被引:1,自引:2,他引:1 下载免费PDF全文
J R Shapiro M L Stover V E Burn M B McKinstry A L Burshell S D Chipman D W Rowe 《The Journal of clinical investigation》1992,89(2):567-573
Mutations affecting the pro alpha 1(I) or pro alpha 2(I) collagen genes have been identified in each of the major clinical types of osteogenesis imperfecta. This study reports the presence of a heritable connective tissue disorder in a family with an osteopenic syndrome which has features of mild osteogenesis imperfecta but was considered idiopathic osteoporosis in the proband. At age 38, while still premenopausal, she was found to have osteopenia, short stature, hypermobile joints, mild hyperelastic skin, mild scoliosis, and blue sclerae. There was no history of vertebral or appendicular fracture. Hip and vertebral bone mineral density measurements were consistent with marked fracture risk. Delayed reduction SDS-PAGE of pepsin-digested collagens from dermal fibroblast cultures demonstrated an anomalous band migrating between alpha 1(I) and alpha 1(III). This band merged with the normal alpha-chains upon prereduction, indicating an unexpected cysteine residue. Cyanogen bromide peptide mapping suggested that the mutation was in the smaller NH2-terminal peptides. cDNA was reverse transcribed from mRNA and amplified by the polymerase chain reaction. A basepair mismatch between proband and control alpha 1(I) cDNA hybrids was detected by chemical cleavage with hydroxylamine:piperidine. The cysteine substitution was thus localized to alpha 1(I) exon 9 within the cyanogen bromide 4 peptide. Nucleotide sequence analysis localized a G----T point mutation in the first position of helical codon 43, replacing the expected glycine (GGT) residue with a cysteine (TGT). The prevalence of similar NH2-terminal mutations in subjects with this phenotype which clinically overlaps idiopathic osteoporosis remains to be determined. 相似文献
52.
Kroppenstedt SN Thomale UW Griebenow M Sakowitz OW Schaser KD Mayr PS Unterberg AW Stover JF 《Critical care medicine》2003,31(8):2211-2221
OBJECTIVES: Reduction of cerebral perfusion during the early phase after traumatic brain injury is followed by a later phase of normal to increased perfusion. Thus, pharmacologically elevating mean arterial blood pressure with the aim of improving cerebral perfusion may exert different time-dependent effects on cortical perfusion, microcirculation, tissue oxygenation and brain edema formation after traumatic brain injury. DESIGN: Randomized, placebo-controlled trial. SETTING: Experimental laboratory at a university hospital. SUBJECTS: A total of 37 male Sprague-Dawley rats subjected to a focal cortical contusion. INTERVENTIONS: At 4 or 24 hrs after focal traumatic brain injury, mean arterial blood pressure was increased to 120 mm Hg for 90 mins by infusing norepinephrine. In rats receiving physiologic saline, mean arterial blood pressure remained unchanged. In the first series, pericontusional cortical perfusion was measured using the laser Doppler flowmetry scanning technique before injury and before, during, and after the infusion period. In a second series, intracranial and cerebral perfusion pressure and intraparenchymal perfusion and tissue oxygen measured within the contused and pericontusional cortex were recorded continuously before, during, and after norepinephrine infusion. Changes in cortical microcirculation were investigated by orthogonal polarization spectral imaging. At the end of each experiment, hemispheric swelling and water content were determined gravimetrically. MEASUREMENTS AND MAIN RESULTS: At 4 and 24 hrs after traumatic brain injury, intravenous norepinephrine significantly increased pericontusional cortical perfusion, which was also reflected by an increase in diameters and flow velocities of pericontusional arterioles and venules. Cerebral perfusion pressure and intraparenchymal perfusion and tissue oxygen were significantly increased during norepinephrine infusion at 4 and 24 hrs. Hemispheric swelling and water content showed no difference between the groups. CONCLUSIONS: After cortical impact injury, early and late intravenous norepinephrine infusion pressure-dependently increased cerebral perfusion and tissue oxygenation without aggravating or reducing brain edema formation. Future studies are warranted to determine long-term changes of short and prolonged norepinephrine-induced increases in mean arterial blood pressure and cerebral perfusion pressure. 相似文献
53.
A C Skjold L R Stover J H Pendergrass P F Corey J A Cattell A E Burkhardt M P Farinelli R J Tyhach J P Albarella R W Trimmer 《Clinical chemistry》1987,33(7):1242-1245
A new reagent strip for the determination of leukocytes in urine (LEUKOSTIX; Ames) is described. The test is based on the esterase activity in leukocytes as a marker. Upon contact between the reagent matrix and a urine containing leukocytes, an amino acid ester is hydrolyzed by the esterase to its corresponding alcohol. The free alcohol then couples with a diazonium salt to produce a purple azo dye. The relative concentration of leukocytes in the urine is obtained by visually comparing the strip reaction with a color chart. Performance of the strip was evaluated in a clinical study involving eight different sites and 867 urine specimens. The comparison method was sediment microscopy; specimens containing five cells or more per high-power field were considered to be positive. Sensitivity was 76.3%, specificity 80.8%. Performance was comparable with that of the CHEMSTRIP LN (Boehringer-Mannheim Diagnostics, Inc.) leukocyte test, which we evaluated concurrently. 相似文献
54.
Reporter gene technology to assess activity of antimycobacterial agents in macrophages. 总被引:2,自引:2,他引:2 下载免费PDF全文
T M Arain A E Resconi D C Singh C K Stover 《Antimicrobial agents and chemotherapy》1996,40(6):1542-1544
Reporter strains of Mycobacterium tuberculosis and Mycobacterium bovis BCG endogenously expressing firefly luciferase were used in bioluminescence assays to evaluate the activities of isoniazid and rifampin against mycobacteria sequestered in human macrophages. This methodology allowed the efficacy of antibiotics against intracellular mycobacteria to be assessed without the labor-intensive procedures and protracted incubation requirements associated with conventional CFU determinations. 相似文献
55.
56.
As the global HIV/AIDS pandemic nears the end of its third decade, the challenges of efficient mobilisation of funds and management of resources are increasingly prominent. The aids2031 project modelled long-term funding needs for HIV/AIDS in developing countries with a range of scenarios and substantial variation in costs: ranging from US$397 to $722 billion globally between 2009 and 2031, depending on policy choices adopted by governments and donors. We examine what these figures mean for individual developing countries, and estimate the proportion of HIV/AIDS funding that they and donors will provide. Scenarios for expanded HIV/AIDS prevention, treatment, and mitigation were analysed for 15 representative countries. We suggest that countries will move in increasingly divergent directions over the next 20 years; middle-income countries with a low burden of HIV/AIDS will gradually be able to take on the modest costs of their HIV/AIDS response, whereas low-income countries with a high burden of disease will remain reliant upon external support for their rapidly expanding costs. A small but important group of middle-income countries with a high prevalence of HIV/AIDS (eg, South Africa) form a third category, in which rapid scale-up in the short term, matched by outside funds, could be phased down within 10 years assuming strategic investments are made for prevention and efficiency gains are made in treatment. 相似文献
57.
Caveat arthroplasty is arthroplasty undertaken to treat a presumed nonneoplastic disorder, which is later determined to be secondary to an extraarticular tumor. We identified 6 patients who had caveat arthroplasty before referral to our orthopedic oncology center. Three patients had completed arthroplasties at an average of 29 weeks before discovery of a neoplasm. Three arthroplasties were aborted after a neoplasm was discovered intraoperatively. Prearthroplasty radiographs of 4 patients were reviewed, all demonstrating evidence of malignancy. Caveat arthroplasty may be avoided if malignancy is considered preoperatively, particularly in patients with atypical symptoms, histories of cancer, and rapid periarticular bone loss. If a neoplasm is discovered intraoperatively, the arthroplasty should be aborted. Patients in whom malignancy is suspected should be referred to a musculoskeletal oncologist. 相似文献
58.
Heterogeneous regional and temporal energetic impairment following controlled cortical impact injury in rats 总被引:1,自引:0,他引:1
Thomale UW Griebenow M Mautes A Beyer TF Dohse NK Stroop R Sakowitz OW Unterberg AW Stover JF 《Neurological research》2007,29(6):594-603
OBJECTIVES: Following traumatic brain injury metabolic stability is impaired. Duration and reversibility of these changes might be important to guide specific interventions. METHODS: To characterize temporal and regional changes in cerebral metabolism, 68 male Sprague-Dawley rats were subjected to a focal cortical contusion. Lesion progression and mitochondrial impairment were determined by magnetic resonance imaging (MRI) and triphenyl tetrazolium chloride (TTC) staining, respectively. Metabolic alterations were determined at hours 6 and 24 and day 7 by measuring extracellular glucose, lactate and hypoxanthine levels with microdialysis catheters placed adjacent and distant to the contusion and by quantifying changes in tissue ATP, lactate and glucose using bioluminescence imaging. RESULTS: The cortical lesion reached its maximal extent at hour 24 and remained confined to the ipsilateral hemisphere. In microdialysate, at hour 6, extracellular hypoxanthine and lactate reached maximal values, thereafter hypoxanthine normalized while lactate remained increased. Extracellular glucose reached the highest values at hour 24 and remained elevated. Bioluminescence imaging revealed heterogeneous changes in areas distant to the contusion. No significant changes were found in ATP content. Slightly elevated tissue glucose until 24 hours in the ipsilateral hemisphere was observed. Following a continuous increase, lactate levels were the highest by 6 hours in the ipsilateral cortex and hippocampus. DISCUSSION: CCI is associated with disturbances in energetic metabolism. Metabolic perturbation is not restricted to the early phase and the contusional region following focal cortical contusion, but also involves hippocampus and primarily uninjured parts of the hemisphere. 相似文献
59.
Bellack AS Green MF Cook JA Fenton W Harvey PD Heaton RK Laughren T Leon AC Mayo DJ Patrick DL Patterson TL Rose A Stover E Wykes T 《Schizophrenia bulletin》2007,33(3):805-822
People with schizophrenia frequently have significant problems in community functioning. Progress in developing effective interventions to ameliorate these problems has been slowed by the absence of reliable and valid measures that are suitable for use in clinical trials. The National Institute of Mental Health convened a workgroup in September 2005 to examine this issue and make recommendations to the field that would foster research in this area. This article reports on issues raised at the meeting. Many instruments have been developed to assess community functioning, but overall insufficient attention has been paid to psychometric issues and many instruments are not suitable for use in clinical trials. Consumer self-report, informant report, ratings by clinicians and trained raters, and behavioral assessment all can provide useful and valid information in some circumstances and may be practical for use in clinical trials. However, insufficient attention has been paid to when and how different forms of assessment and sources of information are useful or how to understand inconsistencies. A major limiting factor in development of reliable and valid instruments is failure to develop a suitable model of functioning and its primary mediators and moderators. Several examples that can guide thinking are presented. Finally, the field is limited by the absence of an objective gold standard of community functioning. Hence, outcomes must be evaluated in part by "clinical significance." This criterion is problematic because different observers and constituencies often have different opinions about what types of change are clinically important and how much change is significant. 相似文献
60.