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RP Jankov CF Boerkoel J Hellmann WL Sirkin Z Tümer N Horn A Feigenbaum 《Canadian Metallurgical Quarterly》1998,87(12):1297-1300
OBJECTIVES: To estimate overdiagnosis (detection of latent carcinomas) as a consequence of screening for prostate cancer. DESIGN: Based on actual screen (first or repeat) detected and interval prostate cancer rates observed in the Florence screening pilot study, a scenario was simulated where males aged 60 years (or 65) had six biennal screens and were followed up for four years. Overdiagnosis was determined as the proportional excess of cancers detected by screening with respect to that expected in its absence. SETTING: City of Florence, Italy, from 1992 through 1995. POPULATION: 2,740 resident males, aged 60 to 74 years. RESULTS: Overdiagnosis was estimated to be 51% (95% confidence limits: 44%-55%) or 93% (85%-101%) for age 60 or 65 at entry. Comparison with other screening experiences obtaining higher detection rates suggests that a more aggressive screening approach could be associated with overdiagnosis estimates as big as 200%-250%. CONCLUSIONS: Screening for prostate cancer is associated with a relevant risk of overdioagnosis. As latent carcinomas can not be presently identified, this would lead to overtreatment in most overdiagnosed cases. The negative consequences of overdiagnosis (knowledge of having a cancer) and of overtreatment (impotence, incontinence, perioperatory death) may be extremely serious. In absence of any scientific evidence of screening benefits (if any) screening should not be recommended as a current practice, but should be limited to prospective controlled studies designed to assess its cost-effectiveness. 相似文献
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HISTORY AND CLINICAL FINDINGS: A 30-year-old previously healthy man suddenly developed double vision, unsteady gait and some difficulty in speech articulation. Within 4 weeks he had become markedly ataxic, unable to walk, stand or sit down unaided. Neurological examination indicated a severe cerebellar syndrome. There were no other abnormal findings on physical examination. INVESTIGATIONS: There was no pleocytosis and no oligoclonal bands in cerebrospinal fluid (CSF). A test for anti-Purkinje cell antibodies was negative in both CSF and serum. Computed tomography and nuclear magnetic imaging (NMI) of the brain were normal. TREATMENT AND COURSE: As a para- or postinfectious or paraneoplastic process was suspected. I.v. immunoglobulin and oral corticosteroids were administered, but without improvement. 13 month later, a mediastinal mass was noted on a chest radiogram. This led to the diagnosis of a stage IA Hodgkin's disease. Retrospectively the cerebellar degeneration was most likely a paraneoplastic change related to the Hodgkin's disease. However, an independent second disease cannot be excluded. While the treatment of Hodgkin's disease was successful, the neurological symptoms remained unchanged. Severe cerebellar atrophy was demonstrated on NMI. CONCLUSION: In case of cerebellar atrophy of undetermined aetiology a paraneoplastic cause should be considered and an underlying malignant disease looked for. 相似文献
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F Jattiot P Goupille I Azais B Roulot M Alcalay J Jeannou D Bontoux JP Valat 《Canadian Metallurgical Quarterly》1999,26(1):150-155
The analysis of differential gene expression has become increasingly important in recent years. Typically, differentially expressed genes are identified in a primary screening procedure, yielding candidate genes whose differential expression has to be verified. We provide a highly sensitive, efficient and nonradioactive differential screening procedure to analyze numerous candidate genes in a single step. This comprises labeling of poly(A)+ RNA of the cell types analyzed with DIG Chem-Link and differential hybridization to the candidate genes fixed on dot blots. DIG Chem-Link allows, to our knowledge, for the first time efficient and direct nonradioactive labeling of RNA in vitro. Advantages of this method include extremely short exposure times and the feasibility to re-use the probes after prolonged storage. Using this procedure, we isolated several genes that are differentially expressed in maturing Langerhans cells. 相似文献
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For the pathological diagnosis of Alzheimer's disease ADRA-NIH recommend the quantification of plaques, without distinguishing their types, and neurofibrillary tangles. However, diffuse plaques may not be specifically associated to such diagnosis, as suggested by several authors and a previous paper. The neurofibrillary degeneration, present not only in neurofibrillary tangles but also in neuropil threads, either free in the neuropil or associated in plaques, could be more closely correlated with the decrease of cognitive functions than the plaques by themselves. In the present work, the efficiency of cholinesterase histochemical techniques and thioflavin-S is compared to the immunocytochemistry for abnormal tau, in two aspects: 1) the quantification of neurofibrillary degeneration, 2) the distribution of this degeneration, when present, within the plaques. It is concluded that immunocytochemistry for tau is the technique that better fulfills both goals, showing a better agreement with the cognitive state. For that reason tau immunocytochemistry is highly recommended in order to improve the anatomopathological diagnosis of Alzheimer's disease. 相似文献
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In rats with primary retinal degeneration, lens extraction combined with total retinal detachment provided a model for injection of a tracer of colloidal carbon into the subretinal space. Electron microscopy and acid phosphatase cytochemistry were subsequently used to analyze the ingestion of tracer by the retinal pigment epithelium. It was found that the attachment, ingestion, and digestion phases of the phagocytic process were apparently preserved. From this evidence it is suggested that there is no lack of phagocytic power in the retinal pigment epithelium of affected rat strains. 相似文献
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Ultrasound scans were used to study 23 cases of abdominal contusion in children, between January 1992 and December 1993. Thirteen boys and 10 girls were studied. They were all aged between 4 and 14 years, with a mean age of 6 years. The main causes of their injuries were road accidents (12 cases) and play (11 cases). Ultrasound scans were normal in 6 patients and pathological in 17 patients. The most frequently observed injuries were visceral effects (12 cases), almost always associated with hemoperitoneum. In three cases, hemoperitoneum was detected in the absence of visceral effects. The spleen (4 cases) and the liver (4 cases) were the most frequently injured organs. The other injuries detected included renal hematoma, bladder rupture and parietal hematoma. Diagnosis on the basis of ultrasound scans was found to be incorrect in three cases where diagnosis was repeated after the scan. One case involved a blocked perforation of the rectum, one a benign cyst and the other a mesenteric cyst. Despite these misdiagnoses, ultrasound scanning is a highly sensitive and specific method for examination of contusions in children. It is very useful and often sufficient for accurate diagnosis, particularly in units with only modest technical support. 相似文献
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The calcium-binding protein (parvalbumin), isolated from carp (Cyprinus carpio) muscle, has been specifically fragmented into two polypeptides by tryptic hydrolysis at the single arginine residue at position 75. Fragment A contains residues 1 leads to 75 and fragment B is composed of residues 76 leads to 108. The fragments have been characterized according to size, amino acid composition, carboxyl- and aminoterminal analysis. Both fragments appear to be homogeneous by these criteria. The intact protein is known to bind 2 mol of calcium per mol of parvalbumin, and although each fragment alone contains all of the essential ligands for the coordination of one Ca2+, neither fragment displays calcium binding activity. Attempts to reconstitute the two fragments, under a variety of conditions, into a functional complex which can bind calcium have been unsuccessful. The side chain of Arg-75 is known to occupy an internal position in the crystalline structure of parvalbumin (Kretsinger, R.H. and Nockolds, C.E. (1973) J. Biol. Chem. 248, 3313), where it is stabilized by an intricate network of hydrogen bonding involving the side chain of Glu-81. Although this internal salt bridge is approx. 20 A from either calcium binding site, it has been suggested that this structural feature of the molecule plays an essential role in the reversible binding of Ca2+. That the side chain of Arg-75 likewise occupies an internal position in the solution structure is indicated by its unavailability for reaction with 1,2-cyclohexanedione under conditions of physiological pH and temperature. However, in the presence of EDTA and at pH 8, it is readily modified by cyclohexanedione. This modification is accompanied by a concomitant loss in calcium binding activity. Reversal of the modification by treatment with hydroxylamine is accompanied by restoration of calcium binding activity. The serum of these data support the hypothesis that Arg-75 plays a critical role in the structural organization and calcium binding activity of the molecule, and in addition, suggests that the integrity of the peptide bond between Arg-75 and Ala-76 may be necessary for establishing the proper micro-environment required for formation of the internal salt bridge between Arg-75 and Glu-81. 相似文献
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LJ Currie MB Harrison JM Trugman JP Bennett GF Wooten 《Canadian Metallurgical Quarterly》1998,51(1):283-285
Proliferation of arterial smooth muscle cells has held center stage as the culprit in restenosis for almost two decades. Many strategies for combating restenosis target smooth muscle replication. However, none have proven beneficial in clinical trials. Indeed, inhibition of smooth muscle proliferation in human patients might produce the undesired effect of destabilizing vulnerable atherosclerotic plaques because these cells furnish the collagen responsible for the biomechanical strength of the plaque. Actually, in some cases the benefit of angioplasty may depend on stimulating smooth muscle replication and collagen elaboration, converting an "unstable" to a more stable plaque. Moreover, recent clinical and experimental evidence suggests that restenosis depends less on neointimal hyperplasia than on constrictive remodeling (i.e., advential scarring, producing a smaller lumen), a process independent of smooth muscle replication. The recognition that plaques vulnerable to disruption often do not produce flow-limiting stenoses highlights a need for reassessment of the strategies to treat or prevent the acute coronary syndromes. We should strive to treat aggressively risk factors such as hyperlipidemia whose control appears to stabilize plaques. Trials are even underway comparing such risk factor management with coronary artery intervention. If we could identify potentially unstable atheroma before they are evident, clinically, we might even contemplate angioplasty of nonsignificant stenoses to induce smooth muscle cell proliferation and reinforce the plaque's fibrous cap. This proposal may seem preposterous, yet we perform "primary" angioplasty every day in patients with an acute myocardial infarction whose "culprit" lesions underlying the thrombus are often not critical. Our knowledge of the biology of restenosis has lagged behind our practice of coronary intervention. Advances in understanding the biology of the complications of interventional therapy, hand in hand with technical advances, should help us to devise more rational and enduring approaches to benefiting our patients. 相似文献
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FJ Accurso 《Canadian Metallurgical Quarterly》1997,3(6):400-403
Pulmonary bronchogenic cysts with tracheobronchial communication may occasionally mimic tension pneumothorax leading to unnecessary thoracostomy. We describe such a case to emphasize that cautious identification of the direction of displacement of the collapsed lung tissue on chest radiograph or computed tomography (CT) may help in differentiating these two diseases. Tension pneumothorax should lead to centripetal compression of the ipsilateral lung toward the hilum while giant bronchogenic cysts result in centrifugal displacement of the adjacent lung away from the hilum. 相似文献
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We describe the MRI changes preceding the onset of myoclonus in two patients whose post-mortem examination confirmed the diagnosis of Creutzfeldt-Jakob disease (CJD). MRI showed changes in the striatum early in the course of CJD (2-6 months after the onset of apathy, interpreted as depression, and 1-2 months before the onset of further clinical symptoms). Only in one patient did electroencephalography record the typical triphasic sharp-waves, 1 month after MRI. 相似文献
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The diagnosis of dementia of Alzheimer type (DTA) in the early stage of the disease may be possible with the development of specialized memory consultations. After this diagnosis, we can inform family and even the patient in some cases, monitor the progression of disease, give or not treatment, and help family for daily life management (money, car driving, administration papers, etc.). The first step is to analyse the memory complaints of the patient and if possible of his family. The difficulties in everyday life are more informative than an anxious complaint of memory and some IADL deficiency appear early: difficulty to use phone, drugs, transports or checks. The patient examination by a practitioner or a neurologist has to be complete, even if normal in most of the cases. The practitioner has to explore without specific material, the main cognitive domain: the "5 words test" illustrates a useful memory tool, analysing two types of recall. We also must observe writing, digit span, naming and verbal fluency. The examination by a psychologist using standardized batteries of tests must always be driven by this clinical exploration using common scales like MMS or ADAS. In very early DTA, we may observe a cognitive decline limited to some aspects of memory (free long term recall, cued recall, working memory...) with a decline of the most controlled attentional tasks. An isolated memory disorder has to be identified either as onset of DTA or as an aging related cognitive decline (ARCD): the difference is qualitative and may appear only on repeated exams by experimented psychologist. 相似文献
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SETTING: The Matiben Chest Clinic at the West Algiers University Teaching Hospital, and 3 outpatient clinics specializing in tuberculosis and lung disease in Algiers. OBJECTIVE: To determine the tolerance and efficacy of a fixed proportion combination of 3 antituberculosis drugs (per tablet: 50 mg isoniazid + 120 mg rifampicin + 300 mg pyrazinamide) given during the first 2 months of a daily 6-month chemotherapy regimen. DESIGN: Random prospective treatment trial comparing a group of 124 patients receiving the triple combination with another group of 126 patients receiving the 3 drugs separately during the initial treatment phase. The continuation phase was identical for the 2 groups. Comparison of tolerance in the first 2 months, and of the failure and relapse rates (respectively at the end of treatment and 24 months after the end of treatment). RESULTS: During the first 2 months side-effects were significantly more common in the group receiving the drugs separately. At the end of treatment and during the following 24 months there were no significant differences in the cumulative rates of observed failures and relapses (2% and 1%). CONCLUSION: The triple combination studied could replace the separate drugs in the initial treatment phase in countries where the bioavailability of the drugs used has been proven. 相似文献
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JM Provenzale ER Heinz TL Ortel BG Macik LA Charles MJ Alberts 《Canadian Metallurgical Quarterly》1994,192(2):531-537
PURPOSE: To study neuroradiologic findings in patients with hypercoagulability due to antiphospholipid antibodies (APAs). MATERIALS AND METHODS: Retrospective review of abnormal angiographic, computed tomographic, and magnetic resonance imaging findings was performed over a 14-month period in patients with APAs, no diagnosis of systemic lupus erythematosus, age less than 65 years, and no other cause of a hypercoagulable state. RESULTS: Fourteen patients (age range, 22-62 years) with APAs had abnormal results at neuroradiologic examination. Abnormal findings on cross-sectional imaging studies included large-artery (n = 3), lacunar (n = 5), and venous infarctions (n = 2); cortical atrophy (n = 5); white matter abnormalities (n = 3); and dural sinus thrombosis (n = 4). Abnormal angiographic findings included large-artery occlusions (n = 2), arterial narrowing that simulated vasculitis (n = 2), and transverse sinus thrombosis (n = 1). CONCLUSION: Presence of APAs should be suspected when no cause is apparent for either (a) an ischemic cerebrovascular event in young and middle-aged adults or (b) dural sinus or cerebral venous thrombosis (c) in patients with recurrent systemic arterial or venous thromboses, especially women with recurrent miscarriages. 相似文献
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Parkinson's disease is a disorder, in which neurons of various neuronal systems degenerate. Furthermore, in such degenerating neurons, the cytoskeleton seems to be affected. In this respect, Parkinson's disease resembles Alzheimer's disease. Since it has been shown, that elevated levels of intracellular calcium can disrupt the cytoskeleton and that the stimulation of glutamate (NMDA) receptors can cause high intracellular concentrations of calcium, it has been suggested, that the stimulation of glutamate receptors plays a role in the slow degeneration in Alzheimer's and Parkinson's disease. In case of the degeneration of the dopaminergic nigrostriatal system in Parkinson's disease, neurons that contain calcium binding protein appear to be less vulnerable than the neurons that lack it, suggesting that calcium binding protein might protect these neurons from degeneration by preventing that cytosolic calcium concentrations increase excessively. And, since there is in the nigrostriatal system a glutamatergic afferent pathway (the prefrontonigral projection) and since dopaminergic nigrostriatal neurons contain postsynaptic NMDA receptors, glutamatergic excitation may play a role in the degeneration of the nigrostriatal system in Parkinson's disease. If so, it may be possible to protect the neurodegeneration of these dopaminergic neurons by NMDA receptor antagonists. 相似文献
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Encephalocraniocutaneous lipomatosis: complete neuroradiologic evaluation and follow-up of two cases
C Parazzini F Triulzi G Russo M Mastrangelo G Scotti 《Canadian Metallurgical Quarterly》1999,20(1):173-176
In order to examine whether kojic acid (KA) exerts a promoting effect on thyroid carcinogenesis, male F344 rats were initiated with N-bis(2-hydroxypropyl)nitrosamine (BHP; 2800 mg/kg body wt, single s.c. injection) and, starting 1 week later, received pulverized basal diet containing 2 or 0% KA for 12 weeks. Untreated control rats were given basal diet for 13 weeks. As an additional experiment, two groups without BHP initiation received basal diet or diet containing 2% KA for 20 weeks. The serum triiodothyronine (T3) and thyroxine (T4) levels were significantly decreased (half to one-third of values of the BHP alone group) and serum thyroid-stimulating hormone (TSH) was markedly increased (13-19 times higher than the values of the BHP-alone group) in the BHP + KA group at weeks 4 and 12. Similar changes in serum thyroid-related hormones were observed in the group with 2% KA alone at week 4, but not at week 20. Thyroid weights were significantly increased in the BHP + KA and KA-alone groups. Focal thyroid follicular hyperplasias and adenomas were observed in 4/5 and 3/ 5 rats in the BHP + KA group at week 4, respectively. At weeks 12, these lesions were observed in all rats in the BHP + KA group. Animals of the KA alone group showed marked diffuse hypertrophy of follicular epithelial cells at weeks 4 and 20. No changes in thyroid-related hormone levels or thyroid histopathological lesions were observed in either the BHP alone or the untreated control groups. Measurement of liver T4-uridine diphosphate glucuronosyltransferase (UDP-GT) activity at week 4 revealed no significant intergroup differences. These results suggest that thyroid proliferative lesions were induced by KA administration due to continuous serum TSH stimulation through the negative feedback mechanism of the pituitary-thyroid axis, with decreases of T3 and T4 caused by a mechanism independent of T4-UDP-GT activity. 相似文献
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The authors examined in detail the clinical and laboratory data and pathologic findings for 12 patients with alcoholic cardiomyopathy who were autopsied in the preceding ten years to determine the types of liver disease prevalent in this population. Neither alcoholic hepatitis nor cirrhosis was present in any patient, and most of the hepatic changes could be related to the effects of acute and chronic congestive heart failure. The major hepatic lesions included centrilobular congestion and/or ischemic necrosis, cardiac sclerosis (fibrosis about central veins and in perisinusoidal spaces), mild canalicular cholestasis, portal fibrosis, and nodular regenerative hyperplasia. This last finding may account for macroscopic nodularity resembling cirrhosis as well as portal hypertension in patients with alcoholic cardiomyopathy. Although alcoholic cardiomyopathy and alcoholic hepatitis or cirrhosis were mutually exclusive in the patients studied, the factors responsible for this are at present uncertain. 相似文献