Isolated infective endocarditis of the pulmonary valve: an autopsy analysis of nine cases

IntroductionInfective endocarditis (IE) of the pulmonary valve is uncommon and usually occurs in conjunction with tricuspid and/or left-sided valvular endocarditis. There have been only sporadic reports of isolated pulmonary valvular infective endocarditis (PVIE). This report documents the pathological features of nine such cases at autopsy.MethodsAmong 155 cases of IE encountered in a 14-year period, we selected nine cases that had isolated PVIE for analysis. The clinical records were reviewed for the patient demographics, presence or absence of underlying cardiac disease or other predisposing factors, and modes of presentation; these were correlated with the relevant investigations. A detailed study of the heart was done in all with special attention to the pulmonary valve morphology.ResultsThe nine cases of isolated PVIE formed 5.8% of the IE cases, seen in six males and three females, largely adults. Seven patients (77.8%) had admissions for about 24 h. Hospital admission was sought for mainly progressive shortness of breath (66.7%) and fever (44.4%). Congenital heart disease was seen in seven (77.8%); two (an infant and an adult) had normal hearts. A single blood sample for blood culture in two patients was negative. Two-dimensional echocardiography, performed in eight, revealed vegetations on the pulmonary valve in four. The pulmonary valve was tricuspid in six cases, bicuspid in two, and unicuspid in one. The vegetations (active in three, active and healing in two, healed in four) were accompanied by concomitant thickening, shortening, perforations, or complete destruction of the cusps. Involvement of the right ventricular outflow tract or the main pulmonary artery was identified in five hearts. Five patients (55.6%) developed pulmonary complications, related to the endocarditis.ConclusionsDetection of PVIE, especially the isolated type, may be underdiagnosed. This condition should be kept in mind during evaluation of patients especially with cardiac anomalies, who present with fever, prominent respiratory symptoms, and negative blood cultures.     

Broad-range PCR and sequencing in routine diagnosis of infective endocarditis

The aim was to evaluate "16S rDNA PCR and sequencing" (PCR) for identification of bacterial DNA in heart valves in routine diagnosis of infective endocarditis (IE). Heart valves from 74 patients with suspected infective endocarditis, and 16 controls were analysed by histology, culture and PCR. Results from blood culture served as the gold standard. Patients were classified according to the Duke criteria. The final classification resulted in 57 definitive cases of IE, 7 possible, and 10 cases without IE. Sensitivity of valve culture was 26% and specificity 62%. Sensitivity of PCR was 72% and specificity 100%. In patients who had received antibiotic treatment for less than 5 days before surgery, sensitivity of culture and PCR were comparable. In patients who had received antibiotic treatment for more than 5 days, sensitivity of valve culture was markedly reduced compared to sensitivity of PCR. In three of seven blood-culture-negative cases PCR was positive, including two cases with non-cultivable bacteria. No PCR samples were contaminated, whereas 35% of valve-culture samples were contaminated. PCR is more sensitive and specific than valve culture, and a valuable supplement to the existing analyses of valve tissue. PCR is necessary to identify the full spectrum of pathogens causing IE. In contrast to sensitivity of culture, sensitivity of PCR was independent of length of antibiotic treatment before surgery.     

Infective endocarditis due to Neisseria meningitidis: two case reports

Two cases of meningococcal endocarditis are described. An 84-year-old man developed sepsis and septic shock and died 15 h after admission to the department. The autopsy revealed aortic endocarditis. Blood and vegetation culture yielded Neisseria meningitidis B:16:P1.5. A 37-year-old man was admitted for fever and rash lasting several weeks. Endocarditis of the bicuspid aortic valve caused by N. meningitidis C:2a:P1.2,5 was found. The patient was successfully treated with penicillin G for 4 weeks. Brief epidemiologic characteristics of invasive meningococcal disease in the Czech Republic are given.     

Fluorescence in situ hybridization in diagnosis of urinary bladder cancer

The paper presents preliminary results of a study of the diagnosis of urinary bladder cancer by fluorescence in situ hybridization (FISH). Specific chromosomal aberrations are shown to be detectable in both proper tumor tissue and urine from patients with urinary bladder cancer; and the pattern of these changes coincides. FISH may identify cells with genetic disorders in urine long before the clinical symptoms of a recurrence occur.     

Infective endocarditis in patients who have undergone transcatheter aortic valve implantation: a review

BackgroundTranscatheter aortic valve implantation (TAVI) has been approved for the treatment of severe aortic stenosis since 2008 and recent trials have shown that TAVI is at least non-inferior to surgical aortic valve replacement (SAVR) with regards to short-term efficacy and safety in patients across all surgical risk profiles. Prosthetic valve endocarditis of the transcatheter heart valve is a feared complication; data on the risk of infective endocarditis (IE) subsequent to TAVI are now gradually emerging.ObjectivesWe set forth to conduct a review of the incidence, diagnosis, microbial aetiologies, prevention, outcome and management of TAVI-IE.SourcesFrom the MEDLINE database we included a total of 12 observational studies and five studies of long-term results from randomized controlled trials.ContentThe incidence of TAVI-IE was reported to be between 0.7% and 3.0% per person-year. The most common microbes were reported to be enterococci, Staphylococcus aureus, streptococci and coagulase-negative staphylococci. International guidelines on prevention strategies of IE recommend good sanitary conditions including cutaneous care, good oral hygiene and good care of dialysis catheters. Antibiotic prophylaxis is recommended by guidelines prior to dental procedures in patients with TAVI; however, evidence is sparse. The majority of the patients included in this review with TAVI-IE had an indication for surgical intervention due to IE (50.0% or more); however, only a small subset of the patients underwent surgery (16.4% or less). The in-hospital mortality was around 25%, i.e. of the same order of magnitude as in prosthetic valve IE in general, but varied substantially between studies (from 11% to 64%).ImplicationsThe US Food and Drug Administration's approval of TAVI in patients at low surgical risk may change the characteristics of patients with TAVI, which may influence the incidence, management, and outcome of patients with TAVI-IE.     

Fluorescence in situ hybridization: A brief review

Fluorescence in situ hybridization (FISH) is used for many purposes, including analysis of chromosomal damage, gene mapping, clinical diagnostics, molecular toxicology and cross-species chromosome homology. FISH allows an investigator to identify the presence and location of a region of cellular DNA or RNA within morphologically preserved chromosome preparations, fixed cells or tissue sections. This report describes in situ hybridization, and discusses the past, present and future applications of this method for genetic analysis and molecular toxicology. © 1996 Wiley-Liss, Inc.     

Fluorescence in situ hybridization for the differential diagnosis between Spitz naevus and spitzoid melanoma

Requena C, Rubio L, Traves V, Sanmartín O, Nagore E, Llombart B, Serra C, Fernández‐Serra A, Botella R & Guillén C
(2012) Histopathology  61, 899–909 Fluorescence in situ hybridization for the differential diagnosis between Spitz naevus and spitzoid melanoma Aims: The differential diagnosis between Spitz naevus and spitzoid melanoma can be extremely difficult, or even impossible. In recent years, many attempts have been made to find specific histopathological or immunohistochemical markers, although none has proved successful. Because the prognosis and treatment of each are very different, it is important to distinguish between these entities. We evaluated the ability of the fluorescence in situ hybridization (FISH) assay–designed to detect the copy number of the RREB1 (6p25), MYB (6q23) and CCND1 (11q13) genes and of centromere 6 (Cep 6)–in order to distinguish between Spitz naevus and spitzoid melanoma. Methods and results: We evaluated 12 spitzoid melanomas and six Spitz naevi from our records. The diagnosis of both conditions was based on previously described histopathological criteria. We obtained valuable results for FISH in eight spitzoid melanomas and five Spitz naevi. Chromosomal aberrations were detected in seven of the eight spitzoid melanomas (FISH‐positive) and in none of the five Spitz naevi. The FISH‐negative spitzoid melanoma was the least typical in its group. Conclusions: FISH was able to distinguish between Spitz naevus and spitzoid melanoma, with a sensitivity of 87.5% and a specificity of 100%. Our findings suggest that FISH could prove a useful tool in the differential diagnosis between these entities.     

先天性心脏病合并感染性心内膜炎的临床及预后分析

目的总结分流型先天性心脏病合并感染性心内膜炎(IE)患者的临床特点、治疗及影响预后的因素。方法分析我院2001年1月-2010年12月收治的51例分流型先天性心脏病合并IE患者的临床资料。结果合并于分流型先天性心脏病的IE占全部IE患者的20.6%,其中室间隔缺损和动脉导管未闭是最常见的先天性心脏病。链球菌属(47.1%)是最常见的致病菌。52.9%的患者出现并发症,主要为瓣膜受损和系统性栓塞。38例患者(58.8%)行手术治疗,其中21例于IE活动期行早期手术。先心病合并IE的死亡率为19.6%。回归分析显示,严重心力衰竭(P<0.05)和神经系统并发症(P<0.05)是死亡率的预测因子,而手术治疗是死亡率降低的独立预测因子(P<0.05)。结论先天性心脏病合并IE者死亡率较高。出现严重心力衰竭和中枢神经系统并发症提示预后不良,手术治疗可显著降低死亡率。     

荧光原位杂交技术在染色体病产前诊断中的应用及前景

荧光原位杂交是近年来发展起来的检测染色体异常的新型技术,在产前诊断中也得到了广泛的应用,成为传统细胞遗传学检测的一种重要补充。本文着重介绍了FISH技术的原理及探针的分类,FISH技术在染色体病产前诊断中的应用及前景。     

Time to blood culture positivity: An independent predictor of infective endocarditis and mortality in patients with Staphylococcus aureus bacteraemia

Objectives

Time to blood culture positivity (TTP), a routinely available parameter in automated blood culture systems, may be a proxy for infectious burden in patients with bloodstream infections. We aimed to study the association between TTP and infective endocarditis (IE), or death, in patients with Staphylococcus aureus bacteraemia.

Case clustering in infective endocarditis: the role of availability bias

Limited data exist regarding the impact of variations in clinical practice and physicians' cognitive bias on the diagnosis of infective endocarditis (IE). As an illustration of these effects, unexpected clustering of IE diagnosis was encountered in a prospectively studied cohort. Transoesophageal echocardiography examinations for suspected IE were performed more frequently following a diagnosis of IE, and were associated with a subsequent cluster of IE cases. The cognitive bias of physicians resulting from a recent case of IE can lead to a transient increase in diagnosing additional cases of IE.     

Capnocytophaga canimorsus: a rare case of conservatively treated prosthetic valve endocarditis

We describe a rare case of prosthetic valve endocarditis caused by the canine bacterium Capnocytophaga canimorsus in a male aged 73 years. The diagnosis of infective endocarditis was unequivocal, as it blood cultures were positive for C. canimorsus and vegetations were detected on transesophageal echocardiography; the modified Duke criteria were fulfilled. PET‐CT showed intense ¹⁸F‐FDG uptake of the prosthetic valve area. The patient was treated with antibiotics alone (no surgery), and is now on life‐long suppressive antibiotic therapy. To our knowledge, this is the third reported case of prosthetic valve endocarditis caused by C. canimorsus and the first one to have been treated conservatively.     

荧光原位杂交技术研究人类体外未受精卵的17号染色体非整倍体

目的 对比两种不同间期核制备方法的效果，并比较25－30岁和31－35岁这两个女性年龄组、不同的体外受精－胚胎移植（in vitro fertilization-embryo transfer,IVF-ET）指征、不同超排方案等与17号染色体非整倍体率之间的关系。方法 采用0.1% Tween 20/0.01 mol/L HCl和3：1的甲醇：冰醋酸两种方法制备人类未受精卵间期核，选用人类17号染色体端粒探针（17qter），按说明书步骤进行荧光原位杂交并在方法上稍作改进。结果 36个未受精卵中，正常17号单体24枚，二体7枚，三体5枚，非整倍体出现率为33.3%（12／36）；25－30岁和31－35岁这两个女性年龄组、不同IVF指征、不同超排方案的患者的17号染色体非整倍体发生率差异无显著性。结论 两种方法信号检出率均为100％，但前者间期核制备效果较好，易于操作，避免甲醇冰醋酸刺激性气味对环境的污染，卵母细胞17号染色体的非整倍性是造成体外受精失败的重要原因之一。     

Development of a dual-color fluorescence in situ hybridization probe set on chromosome 6q to improve cytogenetic diagnosis of lymphoid malignancies

Deletions in the long arm of chromosome 6 are one of the most commonly observed chromosome aberrations in lymphoid malignancies and have been identified as an adverse prognostic factor in subsets of leukemia and lymphoma. Although large deletions can readily be detected with conventional banding methods, subtle rearrangements represent a major diagnostic challenge. To identify and follow up 6q abnormalities that are difficult to detect with conventional banding analysis, we have developed a dual-color fluorescence in situ hybridization probe set on 6q21 and 6q27. We have also demonstrated its potential for clinical applications. While applying this new probe set to clinical cytogenetic studies, we identified a unique t(6;14) translocation in a patient with acute lymphoid leukemia. Because the translocation breakpoint on chromosome 6 is located within a common deletion region in patients with lymphoid malignancies, the determination of this translocation breakpoint will facilitate the identification of a candidate tumor suppressor gene in 6q.     

Haemophilus segnis: a rare cause of endocarditis

This report presents a case of endocarditis due to Haemophilus segnis , which represents a speciation difficulty for the routine laboratory. In this study, a molecular approach provided speciation, which was confirmed phenotypically by a reference laboratory. The use of molecular genotypic analysis is an additional strategy in the investigation of endocarditis. It has applications not only in isolate identification but also in primary detection of infection, particularly in patients whose blood is culture negative by conventional methodologies.     

Identification of host and donor cells in porcine homograft heart valve explants by fluorescence in situ hybridization

The pathogenesis of the primary tissue degeneration that limits the life-span of aortic and pulmonary homografts has still not been revealed. Histopathological studies on homograft explants have not given definitive insight into the eventual fate of donor cells, nor have they demonstrated the assumed importance of host cell ingrowth into the graft tissue. In this experimental study, fluorescence in situ hybridization (FISH) is introduced as a new approach to examine the distribution of host and donor cells in homograft explants. Aortic valve replacement was performed with a cryopreserved porcine aortic homograft in three pigs; donor and recipient were of opposite sex. After 4 months, the grafts were explanted and examined by FISH using a biotinylated porcine Y-chromosome-specific library probe. Following probe detection with FITC-conjugated avidin, a clear distinction could be made between cells of host and donor origin without distorting the histological integrity of the explants. There was ingrowth of donor cells into the graft aortic wall and into the valve leaflet, to some extent. In all explants, remaining donor cells were present, though decreased in number. The introduction of FISH in homograft heart valve research provides a powerful tool to study the fate of recipient and donor cellular elements in situ, and may therefore contribute to a better understanding of the histopathological processes that take place in transplanted homograft valves. © 1997 by John Wiley & Sons, Ltd.     

Fluorescence in situ hybridization (FISH) in the microbiological diagnostic routine laboratory: a review

Early identification of microbial pathogens is essential for rational and conservative antibiotic use especially in the case of known regional resistance patterns. Here, we describe fluorescence in situ hybridization (FISH) as one of the rapid methods for easy identification of microbial pathogens, and its advantages and disadvantages for the diagnosis of pathogens in human infections in the laboratory diagnostic routine. Binding of short fluorescence-labeled DNA or nucleic acid-mimicking PNA probes to ribosomes of infectious agents with consecutive analysis by fluorescence microscopy allows identification of bacterial and eukaryotic pathogens at genus or species level. FISH analysis leads to immediate differentiation of infectious agents without delay due to the need for microbial culture. As a microscopic technique, FISH has the unique potential to provide information about spatial resolution, morphology and identification of key pathogens in mixed species samples. On-going automation and commercialization of the FISH procedure has led to significant shortening of the time-to-result and increased test reliability. FISH is a useful tool for the rapid initial identification of microbial pathogens, even from primary materials. Among the rapidly developing alternative techniques, FISH serves as a bridging technology between microscopy, microbial culture, biochemical identification and molecular diagnostic procedures.