BACKGROUND: Unsupervised fuzzy clustering (UFC) analysis is a mathematical technique that groups together objects in the multidimensional feature space according to a specified similarity measurement, thereby yielding clusters of similar data points that can be represented by a set of prototypes or centroids. METHODS: Since clinical studies of mental disorders distinguish between affected and unaffected individuals, we designed an inclusion/exclusion criteria (cutoff behavioral criteria [CBC]) approach for animal behavioral studies. The effect of classifying the study population into clearly affected versus clearly unaffected individuals according to behaviors on two behavioral paradigms was statistically significant. RESULTS: Here the raw data from previous studies were subjected to UFC algorithms as a means of objectively testing the validity of the concept of the CBC for our experimental model. The first UFC algorithm yielded two clearly discrete clusters, found to consist almost exclusively of the exposed animals in the one and unexposed animals in the other. The second algorithm yielded three clusters corresponding to animals designated as clearly affected, partially affected, and clearly unaffected. The algorithm for physiological data in addition to behavioral data failed to elicit discrete clusters. CONCLUSIONS: The UFC analysis yielded data that support the conceptual contention of the CBC and lends additional validity to our previous behavioral studies. 相似文献
Background Recent data confirmed the importance of 18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in the selection of patients with colorectal hepatic metastases for surgery.
Neoadjuvant chemotherapy before hepatic resection in selected cases may improve outcome. The influence of chemotherapy on
the sensitivity of FDG-PET and CT in detecting liver metastases is not known.
Methods Patients were assigned to either neoadjuvant treatment or immediate hepatic resection according to resectability, risk of
recurrence, extrahepatic disease, and patient preference. Two-thirds of them underwent FDG-PET/CT before chemotherapy; all
underwent preoperative contrast-enhanced CT and FDG-PET/CT. Those without extensive extrahepatic disease underwent open exploration
and resection of all the metastases according to original imaging findings. Operative and pathological findings were compared
to imaging results.
Results Twenty-seven patients (33 lesions) underwent immediate hepatic resection (group 1), and 48 patients (122 lesions) received
preoperative neoadjuvant chemotherapy (group 2). Sensitivity of FDG-PET and CT in detecting colorectal (CR) metastases was
significantly higher in group 1 than in group 2 (FDG-PET: 93.3 vs 49%, P < 0.0001; CT: 87.5 vs 65.3, P = 0.038). CT had a higher sensitivity than FDG-PET in detecting CR metastases following neoadjuvant therapy (65.3 vs 49%,
P < 0.0001). Sensitivity of FDG-PET, but not of CT, was lower in group 2 patients whose chemotherapy included bevacizumab compared
to patients who did not receive bevacizumab (39 vs 59%, P = 0.068).
Conclusions FDG-PET/CT sensitivity is lowered by neoadjuvant chemotherapy. CT is more sensitive than FDG-PET in detecting CR metastases
following neoadjuvant therapy. Surgical decision-making requires information from multiple imaging modalities and pretreatment
findings. Baseline FDG-PET and CT before neoadjuvant therapy are mandatory.
The abstract was presented before the 58th Cancer Symposium of the Society of Surgical Oncology, Atlanta, GA, USA, 2005, and
before the 2005 Congress of the American Hepato-Pancreato-Biliary Association, Fort-Lauderdale, FL, USA. 相似文献
Objective: To assess the relationship between tumor marker carcinoma antigen-125 levels in seminal plasma and serum and fertilization rates in an IVF program, using intracytoplasmic sperm injection (ICSI).
Design: A prospective study.
Setting: IVF Unit, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
Patient(s): Twenty-five infertile patients with severe oligo-terato-asthenospermia syndrome and 25 fertile male donors.
Intervention(s): None.
Main Outcome Measure(s): Serum and seminal plasma carcinoma antigen-125 concentrations and fertilization rate per cycle.
Result(s): In the infertile group, the seminal plasma carcinoma antigen-125 levels ranged from 22.0 to 1,284.0 U/mL (mean level ± SD, 229.9 ± 274.2 U/mL). In the normospermic fertile male donors, the seminal plasma carcinoma antigen-125 concentrations ranged from 12.2 to 336.7 U/mL (mean level ± SD, 110.1 ± 91.6 U/mL). This difference was statistically significant. The mean ± SD ratio between the seminal plasma/serum carcinoma antigen−125 levels differed significantly between the infertile group (47.9 ± 61.3) and the fertile male donors (5.7 ± 3.5). In the infertile group, the ratio between the seminal plasma/serum carcinoma antigen-125 levels was found to be negatively correlated with the oocyte fertilization rate.
Conclusion(s): The ratio between carcinoma antigen−125 levels in the seminal plasma and serum may be an indirect marker for male infertility and fertilization rate in IVF treatment using ICSI. 相似文献
BACKGROUND: From May 1996 to August 1998 a minimal access approach was used for 135 of 200 consecutive surgical atrial septal defects closures in children through young adults ranging in age from 6 months to 25 years (median 5 years). METHODS: A 3.5- to 5-cm midline incision was centered over the xiphoid with division of the xiphoid alone (transxiphoid) or of the lower sternum (ministernotomy); both groups underwent bicaval venous cannulation through the incision. Cardioplegia and aortic cross-clamping were administered through the incision. Cephalad retraction of the sternum with a fixed-arm retractor aided exposure. RESULTS: There have been no early or late deaths and no bleeding or wound complications. No procedure required conversion to a full sternotomy, and no cannulation attempt was abandoned for an alternate site. Cross-clamp and cardiopulmonary bypass times were equivalent to those in the full sternotomy group. The mean length of hospital stay in the ministernotomy group was 2.7 days. CONCLUSIONS: The closure of atrial septal defects can be performed through a transxiphoid or ministernotomy approach, conferring a satisfactory cosmetic result without compromising the safety or accuracy of the repair. 相似文献
This study examined the feasibility and potential clinical utility of magnetic resonance imaging (MRI) evaluation of myocardial perfusion (first-pass contrast enhancement) and viability (myocardial delayed enhancement) in 30 patients with congenital and acquired pediatric heart disease. Good agreement was found between MRI evaluation of myocardial perfusion and viability and analysis of segmental wall motion as well as coronary angiography (n = 10) and single photon emission computed tomography (n = 6). 相似文献
Maldistribution of pulmonary artery blood flow (MPBF) is a potential complication in patients who have undergone single ventricle palliation culminating in the Fontan procedure. Cardiovascular magnetic resonance (CMR) is the best modality that can evaluate MPBF in this population. The purpose of this study is to identify the prevalence and associations of MPBF and to determine the impact of MPBF on exercise capacity after the Fontan operation.
Methods
This retrospective single-center study included all patients after Fontan operation who had maximal cardiopulmonary exercise test (CPET) and CMR with flow measurements of the branch pulmonary arteries. MPBF was defined as >?20% difference in branch pulmonary artery flow. Exercise capacity was measured as percent of predicted oxygen consumption at peak exercise (% predicted VO2). Linear and logistic regression models were used to determine univariate and multivariable predictors of exercise capacity and correlates of MPBF, respectively.
Results
A total of 147 patients who had CMR between 1999 and 2017 were included (median age at CMR 21.8?years [interquartile range (IQR) 16.5–30.6]) and the median time between CMR and CPET was 2.8?months [IQR 0–13.8]. Fifty-three patients (36%) had MPBF (95% CI 29–45%). The mean % predicted VO2 was 63?±?16%. Patients with MPBF had lower mean % predicted VO2 compared to patients without MPBF (60?±?14% versus 65?±?16%, p?=?0.04). On multivariable analysis, a lower % predicted VO2 was independently associated with longer time since Fontan, higher ventricular mass-to-volume ratio, and MPBF. On multivariable analysis, only compression of the branch pulmonary arteries by the ascending aorta or aortic root was associated with MPBF (OR 6.5, 95% CI 5.6–7.4, p?<?0.001).
Conclusion
In patients after the Fontan operation, MPBF is common and is independently associated with lower exercise capacity. MPBF was most likely to be caused by pulmonary artery compression by the aortic root or the ascending aorta. This study identifies MPBF as an important risk factor and as a potential target for therapeutic interventions in this fragile patient population.