Mitochondrial function after associating liver partition and portal vein ligation for staged hepatectomy in an experimental model.

BACKGROUND: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a two-stage strategy to induce rapid regeneration of the remnant liver. The technique has been associated with high mortality and morbidity rates. This study aimed to evaluate mitochondrial function, biogenesis and morphology during ALPPS-induced liver regeneration. METHODS: Male Wistar rats (n = 100) underwent portal vein ligation (PVL) or ALPPS. The animals were killed at 0 h (without operation), and 24, 48, 72 or 168 h after intervention. Regeneration rate and proliferation index were assessed. Mitochondrial oxygen consumption and adenosine 5'-triphosphate (ATP) production were measured. Mitochondrial biogenesis was evaluated by protein level measurements of peroxisome proliferator-activated receptor γ co-activator (PGC) 1-α, nuclear respiratory factor (NRF) 1 and 2, and mitochondrial transcription factor α. Mitochondrial morphology was evaluated by electron microscopy. RESULTS: Regeneration rate and Ki-67 index were significantly raised in the ALPPS group compared with the PVL group (regeneration rate at 168 h: mean(s.d.) 291·2(21·4) versus 245·1(13·8) per cent, P < 0·001; Ki-67 index at 24 h: 86·9(4·6) versus 66·2(4·9) per cent, P < 0·001). In the ALPPS group, mitochondrial function was impaired 48 h after the intervention compared with that in the PVL group (induced ATP production); (complex I: 361·9(72·3) versus 629·7(165·8) nmol per min per mg, P = 0·038; complex II: 517·5(48·8) versus 794·8(170·4) nmol per min per mg, P = 0·044). Markers of mitochondrial biogenesis were significantly lower 48 and 72 h after ALPPS compared with PVL (PGC1-α at 48 h: 0·61-fold decrease, P = 0·045; NRF1 at 48 h: 0·48-fold decrease, P = 0·028). Mitochondrial size decreased significantly after ALPPS (0·26(0·05) versus 0·40(0·07) µm2 ; P = 0·034). CONCLUSION: Impaired mitochondrial function and biogenesis, along with the rapid energy-demanding cell proliferation, may cause hepatocyte dysfunction after ALPPS. Surgical relevance Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a well known surgical strategy that combines liver partition and portal vein ligation. This method induces immense regeneration in the future liver remnant. The rapid volume increase is of benefit for resectability, but the mortality and morbidity rates of ALPPS are strikingly high. Moreover, lagging functional recovery of the remnant liver has been reported recently. In this translational study, ALPPS caused an overwhelming inflammatory response that interfered with the peroxisome proliferator-activated receptor γ co-activator 1-α-coordinated, stress-induced, mitochondrial biogenesis pathway. This resulted in the accumulation of immature and malfunctioning mitochondria in hepatocytes during the early phase of liver regeneration (bioenergetic destabilization). These findings might explain some of the high morbidity if confirmed in patients.

Robust vessel segmentation in fundus images.

One of the most common modalities to examine the human eye is the eye-fundus photograph. The evaluation of fundus photographs is carried out by medical experts during time-consuming visual inspection. Our aim is to accelerate this process using computer aided diagnosis. As a first step, it is necessary to segment structures in the images for tissue differentiation. As the eye is the only organ, where the vasculature can be imaged in an in vivo and noninterventional way without using expensive scanners, the vessel tree is one of the most interesting and important structures to analyze. The quality and resolution of fundus images are rapidly increasing. Thus, segmentation methods need to be adapted to the new challenges of high resolutions. In this paper, we present a method to reduce calculation time, achieve high accuracy, and increase sensitivity compared to the original Frangi method. This method contains approaches to avoid potential problems like specular reflexes of thick vessels. The proposed method is evaluated using the STARE and DRIVE databases and we propose a new high resolution fundus database to compare it to the state-of-the-art algorithms. The results show an average accuracy above 94% and low computational needs. This outperforms state-of-the-art methods.

False-positive results in mammographic screening for breast cancer in Europe: a literature review and survey of service screening programmes.

OBJECTIVE: To estimate the cumulative risk of a false-positive screening result in European mammographic screening programmes, and examine the rates and procedures of further assessment. METHODS: A literature review was conducted to identify studies of the cumulative risk of a false-positive result in European screening programmes (390,000 women). We then examined aggregate data, cross-sectional information about further assessment procedures among women with positive results in 20 mammographic screening programmes from 17 countries (1.7 million initial screens, 5.9 million subsequent screens), collected by the European Network for Information on Cancer project (EUNICE). RESULTS: The estimated cumulative risk of a false-positive screening result in women aged 50-69 undergoing 10 biennial screening tests varied from 8% to 21% in the three studies examined (pooled estimate 19.7%). The cumulative risk of an invasive procedure with benign outcome ranged from 1.8% to 6.3% (pooled estimate 2.9%). The risk of undergoing surgical intervention with benign outcome was 0.9% (one study only). From the EUNICE project, the proportions of all screening examinations in the programmes resulting in needle biopsy were 2.2% and 1.1% for initial and subsequent screens, respectively, though the rates differed between countries; the corresponding rates of surgical interventions among women without breast cancer were 0.19% and 0.07%. CONCLUSION: The specific investigative procedures following a recall should be considered when examining the cumulative risk of a false-positive screening result. Most women with a positive screening test undergo a non-invasive assessment procedure. Only a small proportion of recalled women undergo needle biopsy, and even fewer undergo surgical intervention.

Mammographic screening programmes in Europe: organization, coverage and participation.

OBJECTIVES: To summarize participation and coverage rates in population mammographic screening programmes for breast cancer in Europe. METHODS: We used the European Network for Information on Cancer (EUNICE), a web-based data warehouse (EUNICE Breast Cancer Screening Monitoring, EBCSM) for breast cancer screening, to obtain information on programme characteristics, coverage and participation from its initial application in 10 national and 16 regional programmes in 18 European countries. RESULTS: The total population targeted by the screening programme services covered in the report comprised 26.9 million women predominantly aged 50-69. Most of the collected data relates to 2005, 2006 and/or 2007. The average participation rate across all programmes was 53.4% (range 19.4-88.9% of personally invited); or 66.4% excluding Poland, a large programme that initiated personal invitations in 2007. Thirteen of the 26 programmes achieved the European Union benchmark of acceptable participation (>70%), nine achieved the desirable level (>75%). Despite considerable invitation coverage across all programmes (79.3%, range 50.9-115.2%) only 48.2% (range 28.4-92.1%) of the target population were actually screened. The overall invitation and examination coverage excluding Poland was 70.9% and 50.3%, respectively. CONCLUSIONS: The results demonstrate the feasibility of European-wide screening monitoring using the EBCSM data warehouse, although further efforts to refine the system and to harmonize standards and data collection practices will be required, to fully integrate all European countries. The more than three-fold difference in the examination coverage should be taken into account in the evaluation of service screening programmes.

Cervical screening in Hungary: why does the "English model" work but the "Hungarian model" does not?

A comparison has been made between the English practice and the "Hungarian model" of cervical screening. In England, until 1986, extensive opportunistic screening was the practice, but--as it had no effect on cervical cancer mortality--afterwards, the screening policy was changed to be strictly in line with international recommendations. On the other hand, in Hungary, the "old practice" has been petrified: gynaecologists are the "gatekeepers", a "gynaecological examination completed with smear-taking for cytology" makes up the screening strategy. Although in the frame of a National Public Health Programme all the prerequisites for nationwide organised screening have been provided, and an up-to-date screening strategy declared, 20-times as many smears are taken and analysed outside as inside the programme, and the efforts have had no impact on cervical cancer mortality. This is because "old habits die hard". There is an urgent need to reconsider the screening strategy, and to reorganise the cervical screening practice in Hungary.

The organisation and results of first screening round of the Hungarian nationwide organised breast cancer screening programme.

BACKGROUND: The aim of this paper is to give an overview of organisational issues of the Hungarian nationwide organised breast cancer screening programme and to provide the results of the first screening round of the programme for the years 2002-2003. PATIENTS AND METHODS: Data were derived from the financial database of the National Health Insurance Fund Administration covering the period 2000-2003. Women who underwent mammography screening were included into the study. RESULTS: Uptake of the organised screening programme in 2002-2003 was 45.09%, while the recall rate was 7.23%. Malignant cases represented 65.38% of total surgeries and 0.36% of total number of screened women yielding a cancer detection rate 3.6 per 1000 screened women. Malignant cases of 10.78% were identified as ductal carcinoma in situ, while 89.22% was invasive cancer. Benign to malignant ratio was 0.54 : 1. CONCLUSION: There is therefore an urgent need to closely monitor performance and to review programme policies and procedures with the aim of increasing both the participation rate and the proportion of women eligible to attend screening.