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Objective: To explore the mechanism of noise-induced hidden hearing loss by proteomics. Methods: In October 2022, 64 SPF male C57BL/6J mice were divided into control group and noise exposure group with 32 mice in each group according to random sampling method. The noise exposure group was exposed to 100 dB sound pressure level, 2000-16000 Hz broadband noise for 2 h, and the mouse hidden hearing loss model was established. Auditory brainstem response (ABR) was used to test the change of hearing threshold of mice on the 7th day after noise exposure, the damage of basal membrane hair cells was observed by immunofluorescence, and the differentially expressed proteins in the inner ear of mice in each group were identified and analyzed by 4D-Label-free quantitative proteomics, and verified by Western blotting. The results were statistically analyzed by ANOVA and t test. Results: On the 7th day after noise exposure, there was no significant difference in hearing threshold between the control group and the noise exposure group at click and 8000 Hz acoustic stimulation (P>0.05) . The hearing threshold in the noise exposure group was significantly higher than that in the control group under 16000 Hz acoustic stimulation (P<0.05) . Confocal immunofluorescence showed that the basal membrane hair cells of cochlear tissue in noise exposure group were arranged neatly, but the relative expression of C-terminal binding protein 2 antibody of presynaptic membrane in middle gyrus and basal gyrus was significantly lower than that in control group (P<0.05) . GO enrichment analysis showed that the functions of differentially expressed proteins were mainly concentrated in membrane potential regulation, ligand-gated channel activity, and ligand-gated ion channel activity. KEGG pathway enrichment analysis showed that differentially expressed proteins were significantly enriched in phosphatidylinositol 3 kinase-protein kinase B (PI3K-Akt) signaling pathway, NOD-like receptor signaling pathway, calcium signaling pathway, etc. Western blotting showed that the expression of inositol 1, 4, 5-trisphosphate receptor 3 (Itpr3) was increased and the expression of solute carrier family 38 member 2 (Slc38a2) was decreased in the noise exposure group (P<0.05) . Conclusion: Through proteomic analysis, screening and verification of the differential expression proteins Itpr3 and Slc38a2 in the constructed mouse noise-induced hidden hearing loss model, the glutaminergic synaptic related pathways represented by Itpr3 and Slc38a2 may be involved in the occurrence of hidden hearing loss.
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Potenciais Evocados Auditivos do Tronco Encefálico , Perda Auditiva Provocada por Ruído , Camundongos Endogâmicos C57BL , Ruído , Proteômica , Animais , Camundongos , Perda Auditiva Provocada por Ruído/metabolismo , Perda Auditiva Provocada por Ruído/fisiopatologia , Masculino , Ruído/efeitos adversos , Modelos Animais de Doenças , Limiar Auditivo , Orelha Interna/metabolismo , Perda Auditiva OcultaRESUMO
Gadoxetic disodium (Primovist) is a hepatocyte-specific magnetic resonance imaging (MRI) contrast agent with increasing popularity with its unique dual dynamic and excretory properties in focal liver lesion detection and characterisation. In-depth knowledge of its diagnostic utility and pitfalls in hepatocellular carcinoma (HCC) and liver metastases is crucial in facilitating clinical management. The current article reviews the pearls and pitfalls in these aspects with highlights from the latest research evidence. Pearls for common usage of Primovist in HCC includes detection of precursor cancer lesions in cirrhotic patients. Hepatobiliary phase hypointensity precedes arterial phase hyperenhancement (APHE) in hepatocarcinogenesis. Hepatobiliary phase hypointense nodules without APHE can represent early or progressed hepatocellular carcinoma (HCC) and high-grade dysplastic nodules. In addition, Primovist is useful to differentiate HCC from pseudolesions. Pitfalls in diagnosing HCC include transient tachypnoea in the arterial phase, rare hepatobiliary phase hyperintense HCC, and decompensated liver cirrhosis compromising image quality. Primovist is currently the most sensitive technique in diagnosing liver metastases before curative hepatic resection. Other patterns of enhancement of liver metastases, "disappearing" liver metastases are important pitfalls. Radiologists should be aware of the diagnostic utility, limitations, and potential pitfalls for the common usage of hepatobiliary specific contrast agent in liver MRI.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Meios de Contraste , Sensibilidade e Especificidade , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Estudos RetrospectivosRESUMO
Physiological and pathological processes arising from the breast and anterior chest wall may share similar clinical presentations because of the small volume of male breasts. Therefore, imaging is frequently required to localise and characterise the lesion and guide biopsy when radiological findings are equivocal or suspicious. Mammography or digital breast tomosynthesis (DBT) and ultrasound are the mainstays of breast imaging work-up. Other imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI) and positron-emission tomography (PET) can sometimes augment the investigation and aid treatment planning. This article reviews the key imaging features of a wide spectrum of benign and malignant conditions that involve the male breast and anterior chest wall across various age groups. Familiarisation with the salient radiological findings is essential for reaching an accurate diagnosis and optimising management.
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Neoplasias da Mama , Parede Torácica , Adolescente , Mama/diagnóstico por imagem , Mama/patologia , Neoplasias da Mama/patologia , Criança , Humanos , Masculino , Mamografia/métodos , Intensificação de Imagem Radiográfica/métodos , Parede Torácica/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto JovemRESUMO
Objective: To study the protective effects of metformin on noise-induced hearing loss (NIHL) and its differential protein omics expression profile. Methods: In January 2021, 39 male Wistar rats were randomly divided into control group, noise exposure group and metformin+noise exposure group, with 13 rats in each group. Rats in the noise exposure group and metformin+noise exposure group were continuously exposed to octave noise with sound pressure level of 120 dB (A) and center frequency of 8 kHz for 4 h. Rats in the metformin+noise exposure group were treated with 200 mg/kg/d metformin 3 d before noise exposure for a total of 7 d. Auditory brainstem response (ABR) was used to test the changes of hearing thresholds before noise exposure and 1, 4, 7 d after noise exposure in the right ear of rats in each group. Tandem mass tag (TMT) quantitative proteomics was used to identify and analyze the differentially expressed protein in the inner ear of rats in each group, and it was verified by immunofluorescence staining with frozen sections. Results: The click-ABR thresholds of right ear in the noise exposure group and metformin+noise exposure group were significantly higher than those in the control group 1, 4, 7 d after noise exposure (P<0.05) . The click-ABR threshold of right ear in the metformin+noise exposure group were significantly lower than that in the noise exposure group (P<0.05) . Compared with the noise exposure group, 1035 up-regulated proteins and 1145 down-regulated proteins were differentially expressed in the metformin+noise exposure group. GO enrichment analysis showed that the significantly differentially expressed proteins were mainly involved in binding, molecular function regulation, signal transduction, and other functions. Enrichment analysis of KEGG pathway revealed that the pathways for significant enrichment of differentially expressed proteins included phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt) signaling pathway, focal adhesion, diabetic cardiomyopathy, mitogen, and mitogen-activated protein kinase (MAPK) signaling pathway. Immunofluorescence experiments showed that compared with the noise exposure group, the fluorescence intensity of insulin-like growth factor 1 receptor (IGF1R) in the metformin+noise exposure group was increased, and the fluorescence intensity of eukaryotic translation initiation factor 4E binding protein 1 (eIF4EBP1) was decreased. Conclusion: Noise exposure can lead to an increase in rat hearing threshold, and metformin can improve noise-induced hearing threshold abnormalities through multiple pathways and biological processes.
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Orelha Interna , Perda Auditiva Provocada por Ruído , Metformina , Animais , Limiar Auditivo/fisiologia , Cóclea , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Perda Auditiva Provocada por Ruído/tratamento farmacológico , Perda Auditiva Provocada por Ruído/prevenção & controle , Masculino , Metformina/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Ratos , Ratos WistarRESUMO
Objective: To analyze the epidemiological, clinicopathological and prognostic characteristics of clear cell papillary renal cell carcinoma (CCPRCC) based on Chinese patient population. Method: Patients with renal cell carcinoma diagnosed at Peking University First Hospital from June 2016 to June 2020 were included in this study based on the inclusion and exclusion criteria. All cases were grouped according to CCPRCC, clear cell renal cell carcinoma (ccRCC), and papillary renal cell carcinoma (pRCC), and the general clinical, postoperative pathological and follow-up data of the patients were retrospectively analyzed. Result: A total of 18 CCPRCC patients were enrolled in this study, accounting for 0.44% (18/4 110) of the postoperative pathologically confirmed renal cell carcinoma cases in our hospital during this time period. The age range of the included patients was 28-86 years old, with a median age of 49.5 years old. There were 11/18 males and 7/18 females. All CCPRCC patients had no family history of renal malignant tumors. Among them, only one patient with CCPRCC had related clinical symptoms, that was intermittent waist and abdomen pain, while the other 17 cases were found by physical examination without any related symptoms. Compared with ccRCC and pRCC, there was no significant difference in their end stage renal disease history(χ2ccRCC=0.291, χ2pRCC=1.161,all P>0.05). The maximum diameter of CCPRCC tumor was smaller than pRCC (χ2=-2.280,P =0.027) but not significantly different from ccRCC (χ2=-0.579,P =0.565). The majority of patients with CCPRCC were in pT1, their pathological stage was earlier than the other two types, and their overall survival was better than ccRCC and pRCC (P<0.05). Conclusion: CCPRCC is a type of renal cell carcinoma with unique epidemiology, clinicopathology and prognostic characteristics. Patients with this subtype have an earlier clinical stage and a better prognosis than ccRCC and pRCC.
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Carcinoma de Células Renais , Neoplasias Renais , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos RetrospectivosRESUMO
PURPOSE: As the designated tertiary referral centre for infectious diseases in Hong Kong, our hospital received the city's first group of patients diagnosed with coronavirus disease 2019 (COVID-19). Herein, we studied the earliest patients admitted to our centre in order to clarify the typical radiological findings, particularly computed tomography (CT) findings, associated with COVID-19. METHODS: From 22 January 2020 to 29 February 2020, 19 patients with confirmed COVID-19 underwent high-resolution or conventional CT scans of the thorax in our centre. The CT imaging findings of these patients with confirmed COVID-19 in Hong Kong were reviewed in this study. RESULTS: Ground-glass opacities (GGO) with peripheral subpleural distribution were found in all patients (100%). No specific zonal predominance was observed. All lobes were involved in 16 (84.2%) patients, focal subsegmental consolidations were observed in 14 (73.7%) patients, and interlobular septal thickening was present in 12 (63.2%) patients. No mediastinal lymph node enlargement, centrilobular nodule, or pleural effusion was detected in any of the patients. Other imaging features present in several patients include bronchial dilatation, bronchial wall thickening, and crazy-paving patterns. CONCLUSIONS: Peripheral subpleural GGO without zonal predominance in the absence of centrilobular nodule, pleural effusion, and lymph node enlargement were consistent findings in patients with confirmed COVID-19. The observed radiological patterns on CT scans can help identify COVID-19 and assess affected patients in the context of the ongoing outbreak.
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Betacoronavirus , Infecções por Coronavirus/diagnóstico por imagem , Pneumonia Viral/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , COVID-19 , Progressão da Doença , Feminino , Hong Kong , Humanos , Pulmão/diagnóstico por imagem , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2RESUMO
The aim of this retrospective study was to evaluate the prognostic influence of lymphatic vessel invasion (LVI) in stage I non-small cell lung cancer (NSCLC) patients. From January 2004 to December 2007, LVI was detected in 57 patients with T1N0M0 NSCLC; therefore, 114 patients with the same pathology, T stage, and surgery method, but without LVI, were selected as the control group to compare survival. The overall survival and relapse-free survival rates were estimated using the Kaplan-Meier method, log-rank test, and Cox proportional hazards analysis. The average follow-up length was 59.94 ± 23.1 months. The 5-year overall survival rates of the LVI-negative and the LVI-positive groups were 90.54 and 70.1%, respectively (P = 0.002). A multivariate analysis revealed LVI to be an independent predictive factor (hazard ratio = 4.562; P = 0.004). The 5-year overall survival rates for patients who received postoperative adjunctive therapy and those who did not in the LVI-positive group were 88.2 and 61.5%, respectively, with a P value less than 0.05 in both univariate and multivariate analyses. LVI is a poor prognostic factor in stage I NSCLC patients; postoperative adjunctive therapy is needed to improve the prognosis of NSCLC patients with LVI.
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Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/patologia , Metástase Linfática/patologia , Vasos Linfáticos/patologia , Invasividade Neoplásica/patologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Taxa de SobrevidaAssuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus , Pulmão/diagnóstico por imagem , Pandemias , Administração dos Cuidados ao Paciente/métodos , Pneumonia Viral , Radiografia Torácica/métodos , Tomografia Computadorizada por Raios X/métodos , COVID-19 , Teste para COVID-19 , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/sangue , Pneumonia Viral/diagnóstico , Pneumonia Viral/fisiopatologia , Pneumonia Viral/terapia , SARS-CoV-2 , Avaliação de Sintomas/métodos , Resultado do TratamentoRESUMO
The objective of this study was to evaluate the genotype and allelic frequencies of CYP1A2 in Chinese patients with acute liver injury induced by Polygonum multiflorum. We examined the clinical mechanism of acute liver injury induced by P. multiflorum. According to the diagnostic criteria for drug-induced liver injury (DILI), 43 cases of P. multiflorum-induced liver injury admitted to the First Affiliated Hospital, Zhejiang University were identified between January 2008 and December 2012. An additional 43 control subjects were also chosen. Several alleles, including 1C, 1F, 2, 7, 9, and 11 of CYP1A2 were amplified from genomic DNA and sequenced. We used the chi-square test to determine whether CYP1A2 allele polymorphisms are associated with acute liver injury induced by P. multiflorum. The frequency of the CYP1A2 1C allele was 46.5% in P. multiflorum-induced DILI patients, which was significantly different from the frequency of 27.9% observed in healthy subjects. The frequency of the CYP1A2 1F allele was 63.9% in P. multiflorum-induced DILI patients, compared to 57.0% in healthy controls; the difference was not significant. The allelic frequencies of CYP1A2 2, CYP1A2 7, CYP1A2 9, and CYP1A2 11 were too low to be detected. The frequency of the CYP1A2 1C mutation in Chinese patients with P. multiflorum-induced acute liver injury differed from that in healthy Chinese people, indicating that CYP1A2 1C is probably related to metabolism of P. multiflorum, which is followed by acute liver injury.
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Doença Hepática Induzida por Substâncias e Drogas/genética , Citocromo P-450 CYP1A2/genética , Predisposição Genética para Doença , Polimorfismo Genético , Adulto , Alelos , Povo Asiático , Estudos de Casos e Controles , China , Medicamentos de Ervas Chinesas/efeitos adversos , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polygonum/efeitos adversos , Polygonum/química , Polimorfismo de Nucleotídeo ÚnicoAssuntos
Lesões Encefálicas/diagnóstico por imagem , Corpos Estranhos/diagnóstico por imagem , Traumatismos Cranianos Penetrantes/diagnóstico por imagem , Transtornos Psicóticos/psicologia , Lesões Encefálicas/complicações , Utensílios de Alimentação e Culinária , Traumatismos Cranianos Penetrantes/complicações , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Spatial epidemiology focuses on the use of geographic information systems and spatial analysis to study spatial distribution and change tendency of diseases and explore the health status of specific populations. In recent years, spatial epidemiology has been applied in the field of HIV/AIDS prevention and control. This review summarizes the progress in the application of spatial epidemiology in the analysis of spatiotemporal distribution, non-monitoring area data estimation, influencing factors of AIDS and health resource allocation and utilization to provide reference for its application in the prevention and control of AIDS in the future.
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Síndrome da Imunodeficiência Adquirida , Infecções por HIV , Síndrome da Imunodeficiência Adquirida/epidemiologia , Síndrome da Imunodeficiência Adquirida/prevenção & controle , Sistemas de Informação Geográfica , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Humanos , Análise EspacialRESUMO
Capture-recapture method is an economical and straightforward method widely used in fields such as estimating population size and estimating and adjusting incidence or prevalence. This paper reviews the classical capture-recapture method and its improvement and application in population size estimation in referring the subsequent related work.
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Projetos de Pesquisa , Humanos , Incidência , Densidade Demográfica , PrevalênciaRESUMO
Network scale-up method is an indirect population size estimation method based on social network theory. It is widely used in estimating the hidden population size because it does not need to contact the target population. In order to provide reference for the further application of this method, this paper summarizes the traditional network scale-up method, the progress of this method and its combination with new survey techniques.
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Densidade Demográfica , Humanos , Inquéritos e QuestionáriosRESUMO
Respondent-driven sampling (RDS) is a method of sampling specifically for hidden populations, often applied to transgender women, female sex workers, men who have sex with men, and other groups that are difficult to identify and contact because of stigma and legal constraints. However, this method is gradually applied to the general population. With the continuous improvement of RDS, studies find that the network size of RDS samples can be weighted to estimate the overall situation and population size. This article summarizes the current application progress of RDS in population size estimation and provides ideas for the development of RDS and the use of RDS to carry out relevant research.
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Infecções por HIV , Profissionais do Sexo , Minorias Sexuais e de Gênero , Feminino , Infecções por HIV/epidemiologia , Homossexualidade Masculina , Humanos , Masculino , Densidade Demográfica , Estudos de Amostragem , Inquéritos e QuestionáriosRESUMO
We report a mountain-scale record of erosion rates in the central Patagonian Andes from >10 million years (Ma) ago to present, which covers the transition from a fluvial to alpine glaciated landscape. Apatite (U-Th)/He ages of 72 granitic cobbles from alpine glacial deposits show slow erosion before ~6 Ma ago, followed by a two- to threefold increase in the spatially averaged erosion rate of the source region after the onset of alpine glaciations and a 15-fold increase in the top 25% of the distribution. This transition is followed by a pronounced decrease in erosion rates over the past ~3 Ma. We ascribe the pulse of fast erosion to local deepening and widening of valleys, which are characteristic features of alpine glaciated landscapes. The subsequent decline in local erosion rates may represent a return toward a balance between rock uplift and erosion.
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OBJECTIVE: To compare the diagnostic rate, patient comfort, and complications of ultrasonography-guided breast biopsy using a modified coaxial technique with ultrasonography-guided fine needle aspiration and traditional core biopsy. A secondary objective was to describe the use of the coaxial technique for the biopsy of breast lesions and our initial experience. DESIGN: Retrospective study. SETTING: A regional hospital in Hong Kong. PATIENTS: Patients, who were referred for ultrasonography-guided fine needle aspiration or biopsy from 23 November 2007 to 19 March 2008, were divided into three groups. For breast lesions of 8 mm or smaller, fine needle aspirations were performed. For breast lesions larger than 8 mm, the patients were randomly divided into groups receiving traditional core biopsies and coaxial biopsies. The pathological reports were reviewed. MAIN OUTCOME MEASURES: Diagnostic rate, patient comfort assessed in terms of pain, and any procedural complications. RESULTS: A total of 45 ultrasonography-guided fine needle aspirations or biopsies of breast lesions were performed. All core biopsies using the traditional core technique (n=15) and coaxial technique (n=16) were diagnostic. While for fine needle aspirations, three (21%) of 14 were not diagnostic and repeat biopsies were undertaken for the corresponding patients. Except for one breast lesion biopsied with the coaxial technique that revealed invasive ductal carcinoma, all others yielded benign lesions. The average pain score for coaxial biopsies was 2.2, while for traditional core biopsies and fine needle aspirations, average scores were 3.7 and 3.8, respectively (P=0.022). No procedure-related complication was documented with either of the three techniques. CONCLUSION: Modified coaxial core biopsy of the breast has an optimal diagnostic rate and hence avoids the need for repeat biopsies. It is associated with better patient comfort and no increase in the risk of complications.
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Biópsia por Agulha/métodos , Neoplasias da Mama/patologia , Mama/patologia , Adulto , Idoso , Neoplasias da Mama/diagnóstico por imagem , Feminino , Hong Kong , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Retrospectivos , Fatores de Risco , Ultrassonografia de Intervenção , Ultrassonografia MamáriaRESUMO
Malignant extrarenal rhabdoid tumour (MERT) of the gastrointestinal tract is rarely reported in the literature. This report describes the clinical and pathological features of a malignant rhabdoid tumour of the oesophagus in a Chinese man. Ivor-Lewis oesophagectomy had been performed. The tumour behaved aggressively and the patient died from disseminated malignancy one year later. This is only the second case report of a malignant rhabdoid tumour affecting the oesophagus.
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Neoplasias Esofágicas/patologia , Tumor Rabdoide/patologia , Neoplasias Esofágicas/cirurgia , Evolução Fatal , Humanos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Tumor Rabdoide/cirurgiaRESUMO
In a case of pilomatrixoma, an initial fine needle aspiration (FNA) biopsy of a skin lesion yielded only a monomorphic population of mitotically active basaloid cells with squamous differentiation, without anucleated ghost cells, chronic inflammatory cells or foreign-body giant cells. These findings suggested a metastatic squamous-cell carcinoma or a malignant tumor of adnexal skin. The correct diagnosis was made by repeat FNA, which yielded the basaloid cells and ghost cells characteristics of pilomatrixoma; the FNA diagnosis was confirmed by subsequent excisional biopsy. This case demonstrates that pilomatrixoma should be considered in the differential diagnosis of skin aspirates that contain a dominant population of basaloid cells. The differentiation of pilomatrixoma from malignant lesions of the head and neck region is discussed.
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Neoplasias Cutâneas/patologia , Biópsia por Agulha , Carcinoma de Células Escamosas/patologia , Diagnóstico Diferencial , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A disseminated infection with Penicillium marneffei, a rare human pathogen that may infect both healthy and immunocompromised patients, was diagnosed by fine needle aspiration cytology in a patient infected with the human immunodeficiency virus. The presence of yeast-form organisms with an eccentric or central dot and occasional septate and elongated forms highly suggested the diagnosis, which was confirmed on culture. Establishment of the diagnosis is important because this infection is potentially curable.
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Biópsia por Agulha , Micoses/diagnóstico , Penicillium/isolamento & purificação , Soropositividade para HIV/complicações , Humanos , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade , Micoses/etiologia , PescoçoRESUMO
OBJECTIVE: To detect two novel mutations (C282Y and H63D) of the HFE gene in Chinese patients with hepatic iron overload. DESIGN: Multicentre retrospective study. SETTING: Four public hospitals, Hong Kong. PARTICIPANTS: Fifty Chinese patients who presented from January 1987 through December 1999 with hepatic iron overload from various causes. MAIN OUTCOME MEASURES: The DNA from liver biopsy samples was tested for HFE mutations by restriction fragment length polymorphism analysis. RESULTS: The sample DNA quality was unsatisfactory for analysis of the C282Y mutation in one case and the H63D mutation in nine cases. The C282Y mutation was not detected in any of the 49 satisfactory samples. Three of the 41 samples were heterozygous for the H63D mutation and only one was homozygous, giving an allele frequency of 6.1%. Of the three H63D-heterozygotes, one had beta-thalassaemia major, one had beta-thalassaemia minor, and one had hereditary spherocytosis. None of the 12 patients who were presumed to have primary haemochromatosis were positive for either mutation. CONCLUSIONS: The classical form of human leukocyte antigen-linked hereditary haemochromatosis appears to be absent form this locality. The H63D mutation is found in a minority (9.8%) of the patients, in whom it may act synergistically with an erythropoietic factor.