Positive visualization of implanted devices with susceptibility gradient mapping using the original resolution

In magnetic resonance imaging, implantable devices are usually visualized with a negative contrast. Recently, positive contrast techniques have been proposed, such as susceptibility gradient mapping (SGM). However, SGM reduces the spatial resolution making positive visualization of small structures difficult. Here, a development of SGM using the original resolution (SUMO) is presented. For this, a filter is applied in k‐space and the signal amplitude is analyzed in the image domain to determine quantitatively the susceptibility gradient for each pixel. It is shown in simulations and experiments that SUMO results in a better visualization of small structures in comparison to SGM. SUMO is applied to patient datasets for visualization of stent and prostate brachytherapy seeds. In addition, SUMO also provides quantitative information about the number of prostate brachytherapy seeds. The method might be extended to application for visualization of other interventional devices, and, like SGM, it might also be used to visualize magnetically labelled cells. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.     

Repeat prescribing processes in primary care: a qualitative study

Objective To investigate the characteristics, local agreements and changes regarding repeat prescribing processes in primary health care in Finland. Setting Twenty‐eight municipal health centres nationwide. Method Twenty‐eight physicians and 28 medical receptionists were given semi‐structured telephone interviews about repeat prescribing practices. The repeat prescribing process of each health centre was displayed as a flow chart and the processes were classified according to the quality of the practical flow and the medication review. Key findings There are various ways of carrying out repeat prescribing in different health centres. In some centres, a review of the medications is recognised as part of the repeat prescribing process, but in others there is no systematic review of the patients' medication. Repeat prescribing is often performed in a busy atmosphere. Repeat prescribing systems have evolved over time without proper management, and few local guidelines exist. Conclusions There is a need to reorganise the repeat prescribing systems in primary health care. A regular review of long‐term medications, in particular, needs to become a part of the repeat prescribing process. There is a need for both local and national guidelines.     

There is no transmantle pressure gradient in communicating or noncommunicating hydrocephalus

OBJECTIVE: To examine whether a transmantle pressure gradient exists in adult patients with communicating and noncommunicating hydrocephalus. METHODS: Ten patients participated in the study. The mean patient age was 57 +/- 18 years (range, 20-80 yr); seven patients had communicating hydrocephalus, and three had noncommunicating hydrocephalus. Microsensors were used to measure the intracranial pressure (ICP), for 17 to 24 hours during sleeping and waking periods, in the right lateral ventricle (ICP(IV)) and in the subarachnoid space (ICP(SAS)) over the right cerebral convexity simultaneously. Patient activities and body positions were documented. The hydrostatic pressure difference between the two sensors was calculated from cranial x-rays for four basic body positions and compared with the actual body positions of the patients and the measured difference between the two sensors. For three 10-minute periods, the exact transmantle pressure gradient was calculated for each patient as ICP(IV) - ICP(SAS), adjusted for the hydrostatic pressure difference. RESULTS: The measured pressure difference between the two sensors was always within the limits of the maximal possible hydrostatic pressure difference, and it correlated well with the expected difference for the various body positions: mean correlation coefficient, 0.79 +/- 0.10 (range, 0.65-0.92). The exact mean transmantle pressure was -0.01 +/- 0.24 mmHg (range, -0.4 to 0.4 mmHg). ICP waves caused by cardiac pulse, respiration, and B waves were identical in both spaces. CONCLUSION: This study demonstrates no factual support for existence of a transmantle pressure gradient in nonacute communicating or noncommunicating hydrocephalus.     

Local visual field defects correlate with the multifocal electroretinogram (mfERG) in retinal vascular branch occlusion

BACKGROUND: The value of multifocal electroretinography (mfERG) in the detection of localized retinal dysfunction in vascular branch disease at the posterior pole of the eye is investigated, and mfERG is compared with visual field defects. PATIENTS AND METHODS: 10 eyes of 7 patients were tested, of which 8 eyes had a branch retinal vein occlusion and 2 eyes a branch artery occlusion. First order mfERG's were performed with the VERIS (TM) system, using 61 and 103 hexagons, and visual fields with the OCTOPUS M1 macular program. The number of hexagons with a response density loss (nV/deg (2)) of more than -2.0 standard deviations or of more than - 1.5 StDev, respectively, found in the normal population was compared with the number of disturbed test locations or total sensitivity loss (dB) of M1. RESULTS: Local perimetric defects of various extent correlated well concerning localization and sensitivity loss with mfERG response density loss (nV/deg (2)). The best correlation was the total loss of M1 (dB) versus the number of hexagons out of 103, if the criterion of - 1.5 StDev was applied (p 相似文献   

How safe is safe?--a case of Lactobacillus paracasei ssp. paracasei endocarditis and discussion of the safety of lactic acid bacteria

We report a case of endocarditis due to Lactobacillus paracasei ssp. paracasei, which could be distinguished from Lactobacillus strains used for the fermentation of dairy products by randomly amplified polymorphic DNA-polymerase chain reaction. The safety of biotechnical lactic acid bacteria use is also discussed.     

Comparison of arterialized and nonarterialized orthotopic liver transplantation in mice: prowess or relevant model?

BACKGROUND: New insights into mechanisms of injury in orthotopic liver transplantation (OLT) often come from experiments in small animal models. Mice are particularly suitable because of the growing availability of gene-altered animals and specific antibodies. A validated model of OLT in mice is not available and, in particular, the role of rearterialization is unknown. Therefore, we developed a new model of OLT in mice, and we compared liver injury and animal survival in the presence and the absence of arterial blood supply. METHODS: Syngenic OLT was performed in male Balb/c mice. An arterial segment was removed en bloc with the graft in the donor animal and subsequently implanted in a recipient animal using a combination of suture and cuff technique. In some animals, rearterialization was performed with an end-to-side anastomosis between the recipient aorta and the graft artery using a running suture. Rewarming ischemia time was consistently kept below 20 min. RESULTS: All animals (8/8) survived permanently in the presence of a rearterialized graft, whereas only 50% (4/8) were alive at 2 weeks in the absence of arterial supply ( P=0.025). Serum aspartate aminotransferase levels were significantly lower in the presence of arterial supply at 1 and 3 days and 2 weeks after OLT. Serum levels of alkaline phosphatase normalized within 2 weeks in animals with arterialized grafts, whereas levels remained high (3x normal values) in nonarterialized animals. Histologic examination supported a primary injury to the small bile ducts. Viability of arterialized grafts preserved for 16 hr in cold University of Wisconsin solution was 100%. CONCLUSIONS: This study established a new model of arterialized OLT in mice, which opens new avenues for research.     

Intraoperative radiotherapy given as a boost after breast-conserving surgery in breast cancer patients

Conventional radiotherapy after breast-conserving therapy is confined to 50-55 Gy external beam radiation therapy (EBRT) to the whole breast and 10-16 Gy external boost radiation to the tumour bed or brachytherapy to the tumour bed. Local recurrence rate after breast-conserving surgery varies between 5 and 18%. External boost radiation can partially miss the tumour bed and therefore can result in local failure. Intra-operative radiotherapy (IORT) as a high precision boost can prevent a 'geographical miss'. From October 1998 to December 2000, 156 patients with stage I and stage II breast cancer were operated upon in a dedicated IORT facility. After local excision of the tumour, the tumour bed was temporarily approximated by sutures to bring the tissue in the radiation planning target volume. A single dose of 9 Gy was applied to the 90% reference isodose with energies ranging from 4 to 15 MeV, using round applicator tubes 4-8 cm in diameter. After wound healing, the patients received additional 51-56 Gy EBRT to the whole breast. No acute complications associated with IORT were observed. In 5 patients, a secondary mastectomy had to be performed because of tumour multicentricity in the final pathological report or excessive intraductal component. 2 patients developed rib necroses. In 7 patients, wound healing problems occurred. After a mean follow-up of 18 months, no local recurrences were observed. Cosmesis of the breast was very good and comparable to patients without IORT. Preliminary data suggest that IORT given as a boost after breast-conserving surgery could be a reliable alternative to conventional postoperative fractionated boost radiation by accurate dose delivery and avoiding geographical misses, by enabling smaller treatment volumes and complete skin-sparing and by reducing postoperative radiation time by 7-14 days.