Infections of prosthetic heart valves and cardiac pacemakers

Prosthetic valve endocarditis may be considered present when two fo the following criteria are met: (1) two or more blood cultures are positive with the same organism in the absence of extracardiac infections, (2) evidence of bacterial endocarditis by histology or cultures is obtained from surgical or autopsy specimens, and/or (3) a clinical picture compatible with endocarditis (fever, new or changing regurgitant murmur, splenomegaly, hematuria, or evidence of peripheral emboli) is present. The overall incidence of PVE ranges from 0.98 to 4.4 per cent. Early and late PVE (that is endocarditis developing less than 60 and 60 or more days following valve implantation, respectively) accounts for 18 to 36 per cent and 64 to 82 per cent of infections, respectively. The overall mortality is 53 per cent and is higher in patients with early versus late PVE. Coagulase-negative staphylococci are responsible for a higher percentage of early (43 per cent) than late (28 per cent) infections. Streptococci are more common in late (27 per cent) than in early (3 per cent) PVE, while diphtheroids are most common in early PVE. The diagnosis of PVE may be difficult to establish, especially in patients with postoperative bacteremias who have other potential sources of extracardiac infections. Antimicrobial therapy is generally based on the susceptibility of the offending pathogen. With respect to the use of synergistic combinations, results are controversial, and most available data are derived from patients with native-valve endocarditis. Surgery remains an important aspect of treatment, and the mortality among patients who undergo early surgical intervention, particularly if their illness is complicated, is less than in those who are treated only with antibiotics. Indications for surgery include: (1) moderate-severe refractory congestive heart failure, (2) persistent bacteremia or fungemia, (3) multiple emboli, (4) myocardial abscesses, (5) relapsing PVE, and possibly (6) patients with clinical evidence of PVE and negative blood cultures and persistent fever despite 1 week or more of appropriate antibiotics. Pacemaker infections occur in less than 6 per cent of patients who undergo pacemaker insertion. These infections generally result from wound contamination at the time of surgery, and 75 per cent of infections are due to staphylococci. Staphylococcus aureus causes most infections occurring within 2 weeks after surgery, while S. epidermidis causes most later infections. The need to remove infected pacemakers is controversial.     

A huge low-grade fibromyxoid sarcoma of small bowel mesentery simulating hyper immune splenomegaly syndrome: a case report and review of literature

Introduction

Low-grade fibromyxoid sarcoma (LGFMS) is a rare non epithelial tumour. It usually arises from the smooth muscles of the extremities. It is, however, occasionally reported to arise from other regions of the body.

Case report

We report the case of a 32 year old man who complained of a progressive abdominal swelling of 4 months duration. There was associated abdominal discomfort and weight loss. Abdominal examination revealed a non-tender intra abdominal mass filling the abdomen completely. Abdominal ultrasound suggested a massive splenomegaly. Abdomina Computerized Tomography (CT) scan was not done due to financial constraints. At laparotomy, a large, pearl-coloured mass was found within the mesentery of the proximal jejunum, with dilated, tortuous vessels. It was resected along with the overlying 60cm of jejunum. It weighed 7.5kg. Histology and immunohistochemistry confirmed the diagnosis of lowgrade fibromyxoid sarcoma. Post-operative period was uneventful and there were no features of recurrent after 2 year of follow up.

Conclusion

LGFMS may cause a diagnostic dilemma, especially in a third world setting where preoperative diagnosis is hampered by lack of facilities and poverty. A high index of suspicion is needed for preoperative diagnosis, which is necessary for proper planning of the operation.     

Respiratory gated [18F]FDG PET/CT for target volume delineation in stereotactic radiation treatment of liver metastases

Purpose

The use of 4D-[¹⁸F]fluorodeoxyglucose (FDG) PET/CT in combination with respiratory gated magnet resonance imaging (MRI) in target volume definition for stereotactic radiation of liver metastases was investigated.

Methods and materials

A total of 18?patients received respiration gated FDG-PET/CT and MRI. Data were fused using a rigid co-registration algorithm. The quality of the co-registration was rated on a scale from 1 (excellent) to 5 (poor) for co-registration of MRI with gated PET and ungated PET. Gross tumor volume (GTV) was delineated in CT (GTV?_CT), MRI (GTV_MRI), and PET (GTV_PET). MRI- and PET-based GTVs were defined by three observers each. Interobserver variability was calculated for all patients as well as for subgroups with and without previous treatment of liver metastases. All GTVs were compared for all patients and separately for patients with previous local therapy. In addition, a semiautomatic segmentation algorithm was applied on the PET images.

Results

Co-registration? between MR and PET images was rated with 3.3 in average when non-gated PET was used and improved significantly (p?CT ?was 51.5?ml, GTV_MRI ?51.8?ml, and the average GTV_PET ?48.1?ml. Volumes delineated in MRI were 9.9% larger compared to those delineated in CT. Volumes delineated in PET were 13.8% larger than in MRI. The differences between the GTVs were more pronounced in patients with previous treatment. The GTVs defined in MRI showed an interobserver variability of 47.9% (84.1% with previous treatment and 26.2% without previous treatment). The PET-defined GTVs showed an interobserver variability of 21% regardless of previous treatment. Semiautomatic segmentation did not provide satisfying results.

Conclusion

FDG-PET can distinguish vital tumor tissue and scar tissue, and therefore alters the GTV especially in patients with previous local treatment. In addition, it reduces the interobserver variability significantly compared to MRI. However, respiratory gated PET is necessary for good co-registration of PET and MRI.     

Adaptive radiotherapy for soft tissue changes during helical tomotherapy for head and neck cancer

Purpose

The goal of the present study was to assess the frequency and impact of replanning triggered solely by soft tissue changes observed on the daily setup mega-voltage CT (MVCT) in head and neck cancer (H&;N) helical tomotherapy (HT).

Material and methods

A total of 11 patients underwent adaptive radiotherapy (ART) using MVCT. Preconditions were a soft tissue change >?0.5?cm and a tight mask. The dose–volume histograms (DVHs) derived from the initial planning kVCT (inPlan), the recalculated DVHs of the fraction (fx) when replanning was decided (actSit) and the DVHs of the new plan (adaptPlan) were compared. Assessed were the following: maximum dose (D_max), minimum dose (D_min), and mean dose (D_mean) to the planning target volume (PTV) normalized to the prescribed dose; the D_mean/fx to the parotid glands (PG), oral cavity (OC), and larynx (Lx); and the D_max/fx to the spinal cord (SC) in Gy/fx.

Results

No patient had palpable soft tissue changes. The median weight loss at the moment of replanning was 2.3?kg. The median PTV D_mean was 100% for inPlan, 103% for actSit, and 100% for adaptPlan. The PTV was always covered by the prescribed dose. A statistically significant increase was noted for all organs at risk (OAR) in the actSit. The D_mean to the Lx, the D_mean to the OC and the D_max to the SC were statistically better in the adaptPlan. No statistically significant improvement was achieved by ART for the PGs. No significant correlations between weight and volume loss or between the volume changes of the organs to each other were observed, except a strong positive correlation of the shrinkage of the PGs (ρ?=?+?0.77, p?=?0.005).

Conclusion

Soft tissue shrinkage without clinical palpable changes will not affect the coverage of the PTV, but translates into a higher delivered dose to the PTV itself and the normal tissue outside the PTV. The gain by ART in individual patients—especially in patients who receive doses close to the tolerance doses of the OAR—could be substantial.     

Comparative Assessment of the Shaping Ability of Reciproc Blue,WaveOne Gold,and ProTaper Gold in Simulated Root Canals

Maintaining the original trajectory of the root canal is a major challenge in endodontic therapy, especially in narrow and curved root canals. The present study aims to assess the shaping capacity of three endodontic systems made of different nickel–titanium alloys on simulated curved root canals. Thirty-six endodontic resin blocks (Ref. V040245, VDW) divided into three groups, each of twelve blocks (n = 12), were shaped, photographed, and analyzed: Group 1-Protaper Gold (PTG) (Dentsply Maillefer, Ballaigues, Switzerland) F2 25/08; Group 2-Reciproc Blue (RB), RB 25/08 (VDW, Munich, Germany); Group 3-WaveOne Gold (WOG) (Dentsply Maillefer), WOG 25/07. Each block was standardized and photographed before and after shaping in the same position, with the foramen oriented to the left. Post-shaping images were superimposed onto the initial ones. Thirteen measurement points were used for evaluation, spaced with 1 mm distance from one another, from level 0, apical foramen, to level 12, coronal orifice. The amount of removed resin from inner (X1) and outer (X2) walls, the direction of transportation (X1 − X2), and the centering ability (X1 − X2)/Y were measured, calculated, and comparatively analyzed. Statistical differences (p < 0.05) were observed between the shaping capacity of the considered systems in the middle and coronal thirds. PTG had a better centering ability than WOG and RB in the coronal third, while RB was more centered in the middle third in comparison to both WOG and PTG. In the apical third, the centering capacity of WOG was higher, without being statistically significant. WOG 25/07 and PTG 25/08 tend to cut more on the inner wall of the root canals, and RB 25/08 on the external one.     

马应龙痔疮膏治疗阴囊湿疹效果观察

阴囊湿疹是一种常见的变应性皮肤病，由于其发病部位隐蔽，局部皮肤敏感，剧烈疼痛及瘙痒使病人活动受限，严重影响工作与生活。为减轻病人痛苦，采用马应龙痔疮膏治疗阴襄湿疹，效果好。现介绍如下。     

Studies on the relationship between dental plaque and the hard tissues of healthy and diseased teeth]

1. Dental plaques were detected in all the teeth under investigation, with the exception of impacted teeth. 2. The appearance of the plaques is regular. They occur chiefly in certain zones of the tooth crown and in retention areas. The film thickness ranges from 10 to 60 mum. 3. No alterations of the structure or of the primary texture of the hard tissues were observed on healthy and periodontally diseased teeth. The plaques infiltrate but slightly into the surface. 4. Carious teeth have a different appearance. The plaques infiltrate more or less deeply. They even penetrate into the macroscopically free zones of the enamel as well as of the dentine. The infiltrate is diffuse, especially in regions where the relationship between mineral and organic constituents is distrubed.