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81.
OBJECTIVE: Computer-aided detection (CAD) systems have been used successfully to detect malignant calcifications on mammography, with sensitivities ranging from 86% to 99%. Amorphous calcifications are a subset of small indistinct calcifications of intermediate concern that have a 20% likelihood of being malignant and that are frequently overlooked on mammography. The purpose of our study was to determine the sensitivity of one commercially available CAD system for detecting amorphous calcifications. MATERIALS AND METHODS: A commercially available CAD system evaluated mammograms of 82 patients with 85 mammographically detected and histologically sampled groups of amorphous calcifications (21 malignant, 14 high risk, and 50 benign). The sensitivity of the system for detecting the calcifications on at least one image of the two-view mammographic examination (case sensitivity) and on each individual mammographic image (image sensitivity) was determined. Findings were correlated with results from large core needle biopsy or surgical excision in each case. RESULTS: The CAD system detected amorphous calcifications in 43 of 85 cases (case sensitivity, 51%) and in 59 of 146 mammographic images (image sensitivity, 40%). The case sensitivities by histologic outcome were 57% for malignant calcifications, 29% for high-risk calcifications, and 54% for benign calcifications. An average of 2.0 false-positive marks were displayed per case. CONCLUSION: The CAD sensitivity for malignant amorphous calcifications is markedly lower than previously reported for all malignant calcifications. Breast imaging radiologists who use CAD systems should continue to search diligently for these difficult-to-detect lesions. 相似文献
82.
Shetty VP Wakade AV Ghate S Pai VV Ganapati R Antia NH 《International journal of leprosy and other mycobacterial diseases : official organ of the International Leprosy Association》2003,71(3):210-217
Mycobacteria leprae isolates obtained from 37 referral relapse cases of leprosy (37 skin and 10 nerve biopsy samples) received during the years 1994-2001, were tested for viability and drug sensitivity in the mouse footpad. A significant M. leprae yield in the footpads of control mice was obtained, with 32/47 (68%) isolates (from 26 cases) thus confirming viability. Of the 28 isolates successfully drug tested, 6 (21%) were resistant to one or more drugs. All except one, were multidrug treated cases (5/24 = 21%). One of the isolates was resistant to all three drugs, i.e., dapsone (di-aminodiphenyl sulphone, DDS), rifampin (RFP), and clofazimine (CLF). Two were resistant to two drugs, i.e., DDS and RFP, and each of the others were mono resistant to DDS, RFP, or CLF. Notably, one of the isolates that showed combined resistance to DDS and RFP was derived from a borderline tuberculoid case. Also, in one case skin and nerve showed that discordance viz: M. leprae derived from skin were resistant to RFP, while those derived from nerve tested sensitive to all three drugs, indicating tissue related difference. 相似文献
83.
It has been reported that chloroform administered to BDF1 mice by
inhalation for 2 years at concentrations of 5, 30 or 90 p.p.m. for 6 h/day,
5 days/week induced an increase in renal cell tumors in male but not female
mice exposed to the doses of 30 and 90 p.p.m. A small increase in liver
tumors was statistically significant in the female mice at 90 p.p.m. if the
incidences of carcinomas and adenomas were combined. Because chloroform is
not a DNA reactive mutagen, a 13-week time-course and dose-response study
was conducted under conditions of the original bioassay to examine whether
regenerative cell proliferation was an underlying mechanism of
carcinogenesis. Mice were given bromodeoxyuridine via infusion during the
last 3.5 days prior to necropsy to label cells in S-phase. Chloroform
induced pathology and regenerative cell proliferation, measured as the
labeling index (LI, percentage of cells in S-phase), were assessed
microscopically and immunohistochemically. Male mice exposed to 30 and 90
p.p.m. exhibited a dose-dependent increase in regenerating tubules within
the renal cortex and up to a 31-fold increase in LI. No renal lesions or
increased LI were observed in females. Increased centrilobular to midzonal
hepatocyte degeneration and vacuolation and a 7-fold increase over controls
in the hepatocyte LI were observed in the female mice at 90 p.p.m. at 13
weeks. Males exhibited similar pathology, but the increase in LI was not
sustained. The observed correlations between cytolethality and regenerative
cell proliferation with tumor formation supports extensive evidence that
chloroform induces cancer via a non- genotoxic-cytotoxic mode of action. A
concentration of 5 p.p.m. is the no-observed-adverse-effect level for
nephrotoxicity, cell proliferation and cancer. An appropriate safety factor
applied to this value is a straightforward approach to cancer risk
assessment that is consistent with the mode of action of chloroform.
相似文献
84.
MV Merrick A Notghi N Chalmers AG Wilkinson WS Uttley 《Archives of disease in childhood》1995,72(5):388-392
In 3646 children with at least one confirmed urinary tract infection the prevalence of vesicoureteric reflux at presentation was correlated with progressive renal damage during follow up of not less than two and up to 16 years. Reflux was not demonstrated either at presentation or at any subsequent time in almost one half of the children who suffered progressive renal damage and was not a risk factor for progressive renal damage in boys under 1 year. It was an important risk factor in boys over 1 year and in girls of any age. The risk of progressive renal damage in children in whom micturating cystourethrography (MCU) did not reveal vesicoureteric reflux was substantially greater than in those who indirect isotope voiding study (IVS) did not show reflux. The risk of deterioration for those in whom reflux was demonstrated was similar for both techniques. This discrepancy indicates an appreciably higher false negative rate for the MCU than the IVS. Dilatation of the renal pelvis detected by ultrasound was associated with a significantly increased risk of progressive damage only when associated with reflux, but most children with progressive damage did not have a dilated collecting system at presentation. 相似文献
85.
Measurements of oxygen consumption (VO2) were made during sleep in 10 patients with atopic dermatitis. Two groups of healthy children acted as controls. All subjects were studied in bed in an environmental temperature of 24-26 degrees C, and sleep was confirmed during continuous electroencephalographic monitoring. Mean (SD) values of VO2 in sleeping patients who were not scratching ranged from 4.0 (0.4) to 7.4 (0.7), which was not statistically significantly different from control values which ranged from 3.24 (0.3) to 5.56 (0.4). During scratching (while asleep), which occurred in nine out of 10 patients with atopic dermatitis, the mean values of VO2 ranged from 4.5 (0.04) to 10.4 (2.7), and this was significantly higher than the non-scratching patients and the control values. Scratching during sleep in children with atopic dermatitis is associated with increased VO2. 相似文献
86.
87.
Organization, expression and polymorphism of the human persyn gene 总被引:13,自引:0,他引:13
Ninkina NN; Alimova-Kost MV; Paterson JW; Delaney L; Cohen BB; Imreh S; Gnuchev NV; Davies AM; Buchman VL 《Human molecular genetics》1998,7(9):1417-1424
Persyn is a recently identified member of the synuclein family with a
distinct pattern of expression during pre- and postnatal development of the
mouse peripheral and central nervous systems. As with other synucleins,
persyn is believed to be involved in the pathogenesis of human
neurodegenerative diseases. However, in contrast to other synucleins, high
levels of persyn mRNA expression were also found in advanced breast
carcinomas, suggesting an involvement of the encoded protein in breast
tumour progression. Here we have used an antibody specific to human persyn
to demonstrate that the level of this protein is increased in ageing
cerebral cortex and in breast tumours. We cloned, characterized and
sequenced the human persyn genomic locus and localized it to the long arm
of chromosome 10 in the q23.2-q23.3 region. Sequence information was used
to search for specific mutations in the protein coding regions of persyn
mRNA and the persyn gene in breast tumours and tumour cell lines. No
tumour-specific mutations were found, but two linked polymorphisms in the
coding region were detected, both in mRNA and exons III and IV of the gene.
These results suggest that development of breast tumours correlates with
overexpression of the wild-type persyn protein. Detailed characterization
of the human persyn locus is important for further studies of the
involvement of persyn in neurodegeneration and malignancy.
相似文献
88.
89.
90.
Simulated pulmonary nodules: detection with dual-energy digital versus conventional radiography 总被引:9,自引:0,他引:9
Niklason LT; Hickey NM; Chakraborty DP; Sabbagh EA; Yester MV; Fraser RG; Barnes GT 《Radiology》1986,160(3):589-593
Performance of a prototype dual-energy digital chest radiography unit in detecting calcified and noncalcified simulated pulmonary nodules was compared with that of a highly optimized, conventional system. Nodules ranging in size (0.5, 1.0, and 1.6 cm), in number (five to 11), and in calcium content (0-25 mg) were superimposed over the lungs of a frozen, unembalmed, human chest phantom. For each technique, six observers examined 50 posteroanterior projections with different randomized nodule locations. Detection consisted of locating and assigning a level of confidence to each perceived nodular opacity. The resulting plots of the true-positive fraction versus the mean number of false-positive calls per projection indicate that for both calcified and noncalcified nodules, the digital unit performed significantly better (P less than .01). 相似文献