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Pupils shift their time of day preferences from morningness to eveningness during the age of puberty. Therefore, early school start times may have a negative influence on school functioning, adolescent health and on grade point average. Here, we show that morningness - eveningness influences school performance as measured by the final school leaving/university entrance certificate. One hundred and thirty-two university students aged between 20 and 22 years participated in our study. We found a highly significant positive correlation between the average grading of the final exam and the morningness score, suggesting that pupils with morning preferences performed better in school achievement. Evening types seem at a serious disadvantage because the final exams are used for university entrance decisions.  相似文献   

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N. Gupta, S. K. Arora, A. Rajwanshi, R. Nijhawan and R. Srinivasan
Histoplasmosis: cytodiagnosis and review of literature with special emphasis on differential diagnosis on cytomorphology Background: Human infection with Histoplasma capsulatum runs the gamut from asymptomatic to disseminated disease. In immunocompromised patients, a tiny inoculum can lead to widespread disseminated infection. Early diagnosis and initiation of treatment is therefore important. Objective: To review the cases of histoplasmosis diagnosed on fine needle aspiration cytology (FNAC) and to discuss the clinical presentation, associated inflammatory response, load of organisms and differential diagnosis on cytomorphology in these cases. Methods: Retrospective review of seven cases of histoplasmosis at a tertiary‐care centre during the period from 1998 to 2009 was performed. Clinical presentation along with cytomorphological features were studied and discussed in detail. Results: The mean age of patients was 48.6 years and six out of seven were male. History of immunodeficiency (HIV) was available in five cases. Six patients presented with peripheral and/or abdominal lymphadenopathy. One patient had nodular shadows in both lungs and two also had skin lesions. On cytological smears, a variable load of uniform round to oval, about 2–4 μm in diameter, budding yeasts were seen intracellularly (within histiocytes) as well as extracellularly. In one case (HIV positive), these organisms were also seen within neutrophil polymorphonuclear leucocytes. In two cases, an inflammatory response in the form of epithelioid cell granulomas along with multinucleated giant cells was seen. Conclusions: FNAC is a reliable tool to recognize infection with H. capsulatum in tissues. This infection can cause a variable inflammatory response, which should be considered while reporting on such cases.  相似文献   

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Two zooid forming strains and four non-zooid strains of the green chlorococcal alga Scenedesmus obliquus were compared in terms of growth, morphological and physiological characteristics. Large differences were observed among the strains grown under various growth conditions (light and temperature). The assumption that the zooid forming strains may be similar was not confirmed. Since they considerably differed in daughter cells morphology, photosynthesis, growth rate in batch culture or commitment to cellular division. Molecular-genetic comparison of 18S RNA/DNA might distinguish zooid forming strains from non-zooid ones.  相似文献   

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OBJECTIVE: To elucidate three-dimensional (3-D) cytomorphology and its relationship with clinical stage in fine needle aspiration biopsy (FNAB) of papillary thyroid carcinoma (PTC). STUDY DESIGN: FNAB was performed in tumors from 34 patients with PTC. The aspirate was stained and observed under a light microscope (LM). The aspirate was also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). Findings under SEM were correlated with the presentation under LM and also with clinical stage. As a control, FNAB was also performed on a normal part of the thyroid in six patients. RESULTS: Under SEM, normal thyroid cells appeared as round, scattered cells or sheets with a uniform honeycomb cellular arrangement. In PTC, cell sheets with uniform nuclear morphology under LM usually showed a uniform cell arrangement and with distinct cell borders under SEM. Cell sheets with nuclear pleomorphism under LM usually showed a more-disorganized arrangement and with indistinct cell borders under SEM. PTC at advanced clinical stages usually presented with a disorganized cell arrangement, indistinct cell borders and loss of microvilli. CONCLUSION: 3-D cytomorphology in FNAB of PTC was related to clinical stage and might be a prognostic factor for PTC.  相似文献   

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This article reports on the sensitivity and positive predictive value of clinical diagnosis of benign and malignant skin tumors by expert plastic surgeons in an Israeli clinic. Most published reports have focused on the sensitivity of clinicians' diagnoses, a general measure of the physician's skill that does not predict the rate of accuracy of a physician's diagnoses. Our study of 835 lesions in 778 patients, one of the largest Israeli series, assesses the clinical diagnosis of malignant and benign skin tumors and is one of the few that provide information on the positive predictive value, the measure that is of interest to both physicians and patients. The majority of tumors were benign (56.8 percent), 31.6 percent were malignant, and 11.6 percent were premalignant. Among the 474 benign lesions, 46 percent were nevi. The most common nevi subclass was compound nevi (53 percent), 9 percent of the nevi were dysplastic, and 5 percent were blue nevi. The most common malignant tumor was basal cell carcinoma, accounting for 78 percent of malignant tumors.Although sensitivity for clinical diagnosis of malignancy was 91.3 percent, the positive predictive value for clinical diagnosis of malignancy was 71.3 percent. The sensitivity rate for clinically diagnosing premalignant tumors was 42.3 percent, whereas the positive predictive value for these diagnoses was higher (64.1 percent). The sensitivity rate for diagnosis of all benign lesions was 85.9 percent, and the positive predictive value was 94.2 percent. The sensitivity rate for diagnosis of all nevi was 87.6 percent, and the positive predictive value was 85.7 percent: i.e., only seven of the 218 pathologically proven diagnoses of nevi (3.2 percent) were falsely diagnosed as malignant lesions. Even more interestingly, five of the 223 clinical diagnoses of nevi (2.2 percent) were pathologically proven to be malignant melanomas, and seven were found to be premalignant lesions (3.1 percent). It was concluded that publications which report only on the sensitivity neglect to provide information of interest regarding the positive predictive value. Often, positive predictive value is qualitatively different from the sensitivity, and thus relying only on the sensitivity may lead to incorrect evaluation of a clinical judgment, which may result in erroneous surgical decisions.  相似文献   

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Two surgeons in a health maintenance organization group practice performed 280 fine needle aspirations (FNAs) on 257 palpable breast lesions in 200 patients. The cytology was interpreted by four pathologists at a community hospital. FNA cytology had a sensitivity of 96% and a specificity of 94% in these cases; there were no false-positive diagnoses of cancer. FNA cytology improved the identification of benign disease and decreased the risk of missing cancers. FNA cytology also improved the predictive value of mammographic information and was more helpful than mammography in demonstrating the need for biopsy of small palpable lesions that turned out to be "minimal" breast cancers.  相似文献   

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Chang TC  Wu SL  Hsiao YL 《Acta cytologica》2005,49(5):477-482
OBJECTIVE: To elucidate the pitfalls in the diagnosis of medullary thyroid carcinoma (MTC) by fine needle aspiration cytology (FNAC) and the relationship of cytomorphology to RET proto-oncogene mutations. STUDY DESIGN: Cytomorphology was reviewed in the fine needle aspiration slides of 34 patients with MTC proven by surgery and pathology. Germline or somatic RET proto-oncogene mutations were determined using polymerase chain reaction-based sequencing in 15 of 34 patients, and the relationship to cytomorphology was evaluated. RESULTS: Twenty-eight (82.4%) of 34 cases were diagnosed correctly as MTC by FNAC, 3 cases were misdiagnosed as follicular neoplasm and 1 as desmoid, and 2 cases were suspicious for MTC. The main reason for misdiagnosis was overlooking the slight angular shape of the nuclei or atypical changes. In 15 of 34 cases with germline or somatic RET proto-oncogene mutations determined, 10 cases had a germline mutation, and 1 had only a somatic mutation. There were 4 cases that had neither germline nor somatic RET proto-oncogene mutations. Cells with small/round and spindled forms were the predominant findings of codon 918 ATG-->ACG mutation, and cells with small/round and large oval to polygonal forms were the main findings of codon 634 mutations. There were no misdiagnoses in patients with RET proto-oncogene mutations. CONCLUSION: FNAC is a good diagnostic method for MTC. Codon 918 mutation correlates mainly with small/round and spindled cells and codon 634 with small/round, large oval to polygonal forms.  相似文献   

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The aim of the study was to analyze the clinical prevalence and pathohistological correlation of dysplastic nevi. In the period between 2000 and 2009, in the Outpatient Clinic of Referral Centre for Melanoma of the Ministry of Health and Social Welfare of the Republic of Croatia, 12,344 patients were examined, and 35.07% of them were surgically removed in the same institution. Among the patients, 69.16% had clinically diagnosed melanocytic tumor. Out of them, 28.39% were dysplastic. Dysplastic nevus was pathohistologically diagnosed in 20.02% of pathohistologically diagnosed melanocytic tumors. There was women predominace among patients with clinically diagnosed dysplastic nevi (65.22%). The most frequent localization was the trunk in both sexes, women 78.18%, men 76.75%. The coincidence of clinical and pathohistological diagnosis of dysplastic nevus was 30.70%. The results of this study, based on a large number of patients could be a significant contribution in understanding characteristics of dysplastic nevus, its clinical and pathohistological complexity. We hope that the data will contribute to the creation of general accepted protocols in the diagnostics of dysplastic nevus.  相似文献   

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The histology and histochemistry of the interrenal gland of twenty avian species have been described in this report. The avian interrenal tissue, on the basis of nuclear orientation and other cytomorphic features, can be classified into six cytologically distinct types. Cytomorphic organization within the interrenal tissue of these avian species also indicates some regional demarcation into subcapsular and central zones. Zonal demarcation in the interrenal tissue of these birds has also been indicated from chemocytological investigation. Paradoxically not much of correspondence was noticed in the cytologic and cytochemical patterns. The cytological and cytochemical studies fail to indicate any phylogenetic trend within the interrenal tissue of the birds under investigation.  相似文献   

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OBJECTIVE: To study the discriminatory capacity of textural variables to classify the nuclei of breast tumor cells as benign or malignant, using a statistical approach. STUDY DESIGN: Image analysis techniques were used to automatically segment nuclei of cells obtained by fine needle aspiration and Papanicolaou stained. The sample comprised 95 cases of malignant lesions and 47 cases of benign lesions (approximately 25 nuclei per case), and 27 textural variables were measured. Two methods were used to analyze the data: classification and regression trees (CART) and discriminant analysis. RESULTS: The variance in gray levels was the most decisive variable in the CART analysis, correctly classifying 57% and 97% of benign and malignant cases, respectively. Discriminant analysis yielded the best results, correctly classifying 79% and 85% of benign and malignant cases, respectively. CONCLUSION: The classifier obtained by a statistical approach to the textural analysis of Papanicolaou-stained nuclei did not prove useful for diagnostic discrimination. Staining techniques that are not chromatin specific are highly variable, and other features have proven more effective with this type of staining.  相似文献   

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OBJECTIVE: To analyse the morphological changes in tuberculous lymph nodes and the clinical response during short course anti tubercular chemotherapy. METHODS: Thirty-six patients with tuberculous lymphadenitis under treatment were followed up clinically and cytologically at 0, 2, 4 and 6 months. RESULTS: Twenty-six (72.2%) patients had palpable lymph nodes at the end of chemotherapy. Of the 14 patients with residual lymph nodes exceeding 1 cm in size, 92.8% (13) still had evidence of continuation of the disease. Acid-fast bacilli could be found in 38.8% patients at the end of 6 months. Intense lymphocytic infiltration of granulomata in the early phase of chemotherapy predicted a favourable outcome. CONCLUSIONS: Following completion of anti-tubercular treatment a significant percentage of patients have persistent lymphadenopathy and harbour the disease. Morphological follow up of these patients is essential as they may be at increased risk of relapse.  相似文献   

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The Epstein-Barr virus (EBV) is a member of the herpes family of viruses and is very common in humans. EBV is most often associated with infectious mononucleosis. However, it is estimated that 1% of tumors including lymphoproliferative, epithelial and mesenchymal are linked to EBV infection. EBV has a tropism for certain epithelial cells, lymphocytes and myocytes. Like other herpesviruses, EBV has both lytic and latent phases of infection. In the latent form, EBV-encoded genes ensure the survival of the viral genome, allowing it to circumvent the host's immune surveillance by limited expression of viral proteins and carries with it the risk of neoplastic transformation. Cytologists are likely to encounter EBV-associated malignancies in cytology material but unlike other herpesviruses, EBV does not evoke a viral cytopathic effect. The manifestation of EBV-related tumors is also often variable depending upon the patient's immune status. Therefore, knowledge of the patient's EBV status and immune competence (e.g. HIV-infection or transplant-related immunosuppression) combined with the cytomorphology and results of ancillary studies are often all required to make a diagnosis of EBV-associated malignancy. This review discusses the unique cytomorphology and ancillary studies required to diagnose EBV-related neoplasms.  相似文献   

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