Applying spatial distribution analysis techniques to classification of 3D medical images

OBJECTIVE: The objective of this paper is to classify 3D medical images by analyzing spatial distributions to model and characterize the arrangement of the regions of interest (ROIs) in 3D space. METHODS AND MATERIAL: Two methods are proposed for facilitating such classification. The first method uses measures of similarity, such as the Mahalanobis distance and the Kullback-Leibler (KL) divergence, to compute the difference between spatial probability distributions of ROIs in an image of a new subject and each of the considered classes represented by historical data (e.g., normal versus disease class). A new subject is predicted to belong to the class corresponding to the most similar dataset. The second method employs the maximum likelihood (ML) principle to predict the class that most likely produced the dataset of the new subject. RESULTS: The proposed methods have been experimentally evaluated on three datasets: synthetic data (mixtures of Gaussian distributions), realistic lesion-deficit data (generated by a simulator conforming to a clinical study), and functional MRI activation data obtained from a study designed to explore neuroanatomical correlates of semantic processing in Alzheimer's disease (AD). CONCLUSION: Performed experiments demonstrated that the approaches based on the KL divergence and the ML method provide superior accuracy compared to the Mahalanobis distance. The later technique could still be a method of choice when the distributions differ significantly, since it is faster and less complex. The obtained classification accuracy with errors smaller than 1% supports that useful diagnosis assistance could be achieved assuming sufficiently informative historic data and sufficient information on the new subject.     

Contraception for adolescents after abortion

Introduction Preventing repeated unplanned pregnancy among adolescents is still a challenge because many of them fail to use effective contraception after abortion.

Objective To review currently recommended options of methods and counselling for effective prevention of repeat pregnancies in adolescents.

Methods Review of the literature that was identified through the Medline, ScienceDirect, Google and Popline databases and relevant expert opinions.

Results Counselling needs to be adapted to the needs, values and lifestyle of adolescents. The best results are achieved with nondirective or active contraceptive counselling, followed by regular check-ups and cautious and attentive approach in the management of doubts, prejudices and side effects related to the contraceptive chosen. Adolescents should initiate contraception immediately after abortion: the motivation for choosing an efficacious method is highest at that time; resumption of ovulation following induced abortion occurs on average after three weeks; more than half of these girls will resume sexual activity within two weeks after pregnancy termination. Long-acting reversible contraception use during adolescence is safe and most effective. However, achieving a high long-term continuation rate is especially challenging in adolescents; this is due to developmental and environmental characteristics that influence their contraceptive behaviour.

Conclusion Adolescents should immediately after abortion initiate a reliable contraceptive method, preferably one whose efficacy is not user-dependent. Providing an appropriate health care would contribute to achieving continuity in the prevention of repeat pregnancy.     

Billateral Polycystic Kidneys in a Girl with WAGR Syndrome

The WAGR contiguous gene deletion syndrome is a combination of Wilms tumor, aniridia, genito-urinary abnormalities, and mental retardation. An 8.5-year-old girl was initially investigated at the age of 18 months for congenital bilateral aniridia, cataracts, glaucoma and epicantus. The ultrasound (US) scan showed polycystic kidney disease. FISH study revealed deletion of the WT1 and PAX6 gene in the 11p13 WAGR region. Forty days after the first kidney US, the second US revealed a 3 cm tumor in the right kidney: a Wilms tumour, treated successfully with the Wilm’s tumor protocol. The authors conclude that the identification of the deletions in the WAGR region in patients with aniridia should definitely be done. In addition, Wilms tumor can have a very rapid growth, which, per se requires frequent and careful ultrasound kidney controls. Polycystic kidneys can be part of the WAGR presentation.     

Ceruloplasmin and antioxidative enzymes in pre-eclampsia

Objective: To evaluate diagnostic value of ceruloplasmin together with other enzymatic and nonenzymatic antioxidants (superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and uric acid) and to evaluate the level of oxidative stress in patients with pre-eclampsia (PE) and compare it with normal pregnancy.

Methods: In this prospective study, antioxidative markers were investigated in two groups of pregnant women: patients with pre-eclampsia (n?=?32) and the healthy pregnant women (n?=?60). The following antioxidative markers and enzymes were evaluated: serum ceruloplasmin levels, uric acid, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px).

Results: Serum levels of ceruloplasmin, uric acid and SOD were significantly higher in the PE group compared to the control group. Serum levels of GSH-Px were not significantly higher in the PE group compared to the control group. Serum ceruloplasmin and serum uric acid have the best diagnostic accuracy for oxidative stress in PE and are more accurate compared to antioxidative enzymes -SOD and specially more accurate than GSH-Px.

Conclusions: Serum ceruloplasmin level may have significant role as the markers of oxidative stress in pre-eclampsia especially when used in combination with uric acid levels.     

Addressing multiple breast cancer risk factors in African-American women

This pilot study explored the acceptability and feasibility of and estimated the effectiveness of a weight loss/breast health intervention designed to reduce breast cancer risk in African-American women ages 35-65. The study had a one-group repeated-measures design and took place in a community setting. Forty-four African-American women were recruited, 35 completed the program, and 30 returned for the one-year follow-up. The pilot intervention was three weeks in duration and included twice-weekly exercise classes and weekly active learning seminars that addressed weight loss, breast health, healthy eating, and leading an active life. Measures included those of behavior related to diet, physical activity, and breast health. Satisfaction questionnaires and focus groups were also used to assess acceptability and cultural competency. Statistical analyses included Paired t-tests and Wilcoxon signed ranks tests. Significant results postintervention showed improved physical activity, dietary, and breast health behaviors. Results suggest the acceptability, feasibility, and effectiveness of this comprehensive weight/loss breast health program in reducing multiple breast cancer risk factors among African-American women.     

Modulation of corticomuscular coherence by peripheral stimuli

The purpose of this study was to investigate the effects of peripheral afferent stimuli on the synchrony between brain and muscle activity as estimated by corticomuscular coherence (CMC). Electroencephalogram (EEG) from sensorimotor cortex and electromyogram (EMG) from two intrinsic hand muscles were recorded during a key grip motor task, and the modulation of CMC caused by afferent electrical and mechanical stimulation was measured. The particular stimuli used were graded single-pulse electrical stimuli, above threshold for perception and activating cutaneous afferents, applied to the dominant or non-dominant index finger, and a pulsed mechanical displacement of the gripped object causing the subject to feel as if the object may be dropped. Following electrical stimulation of the dominant index finger, the level of β-range (14–36 Hz) CMC was reduced in a stimulus intensity-dependent fashion for up to 400 ms post-stimulus, then returned with greater magnitude before falling to baseline levels over 2.5 s, outlasting the reflex and evoked changes in EMG and EEG. Subjects showing no baseline β-range CMC nevertheless showed post-stimulus increases in β-range CMC with the same time course as those with baseline β-range CMC. The mechanical stimuli produced similar modulation of β-range CMC. Electrical stimuli to the non-dominant index finger produced no significant increase in β-range CMC. The results suggest that both cutaneous and proprioceptive afferents have access to circuits generating CMC, but that only a functionally relevant stimulus produces significant modulation of the background β-range CMC, providing further evidence that β-range CMC has an important role in sensorimotor integration.     

Possibilty of the lower third molar eruption--radiographic analysis

BACKGROUND/AIM: To assess the possibility of the eruption of the lower third molar on the basis of the measured parameters: retromolar space, mesiodistal crown width of a molar and the third molar angulation. METHODS: The investigation included 104 patients both sexes (43 boys, and 61 girls), 16 to 25 years old (mean age, 18 years). It was performed using the orthopanthomographic radiographs analysis of those patients. Each radiograph was covered by tracing paper, and the contoures of the following anatomic details were drawn: a) the crown and root contours of third molars, upper and lower central incisors, distal molars in occlusion, anterior edge of ramus mandible, b) lines: 1. the occlusal plane, 2. the line of retromolar space, 3. the mesiodistal crown width of third molar, 4. the axial shaft of the third molar and the distal angle between occlusal plane and the axial shaft of the third molar. The values were measured with an orthodontic caliper: the diameter of retromolar space, diameter of mesiodistal width, the value of distal angle between occlusal plane and axial shaft of molar. RESULTS: A favourable angulation of the lower third molar (more than 60 degrees) was found in, boys (left 27.90%, right 32.55%), girls (left 39.34%, right 37.77%). A favourable relationship between the diameters of mesiodistal width of the third molar and retromolar space was found in, boys, (left 13.59%, right 16.27%), girls, (left 8.19%, right 14.75%). A favourable relationship between the diameters of mesiodistal width of the third molar and the retromolar space and the angulation was found in boys, (left 9.30%, right 11.62%), girls, (left 6.56%, right 9.83%). CONCLUSION: There was not any statistically significant difference found between the relation of the retromolar value, third molar mesiodistal diameter, or of the third molar angulation to the left and the right side nor of their mutual relations in comparing boys and girls. A favourable prognosis was found in 9.33% of the patients.     

Venous bubble count declines during strenuous exercise after an open sea dive to 30 m

INTRODUCTION: The effect of post-dive exercise on bubble formation remains controversial, although the current practice of divers and aviators is to avoid strenuous exercise after diving. Previously, we have shown that exercising 24 h before a dive, or during a decompression stop, significantly reduces bubble formation in man. The objective of this study was to determine whether a short period of strenuous post-dive exercise promotes venous bubble formation. METHODS: Seven male military divers performed an open-sea field dive to a maximum depth of 30 m for 30 min. At maximum depth, subjects performed mild underwater fin swimming, followed by standard decompression. Diving was followed by a post-dive exercise session consisting of short, strenuous incremental upright cycle ergometry, up to 85% of maximal oxygen uptake, for about 10 min. Subjects were monitored for venous gas bubbles in the right heart with an echo-imaging system starting 20 min post-dive while in the supine position, during cycle ergometry in the seated upright position, and immediately after exercise in a supine position. RESULTS: The average number of bubbles was 1.5 +/- 1.4 bubbles x cm(-2) 20 min after diving. Changes in posture from supine to seated upright resulted in significant reduction of bubbles to 0.6 +/- 1.3 bubbles x cm(-2) (p = 0.043), with further reduction to 0.2 +/- 0.3 bubbles x cm(-2) at the end of exercise (p = 0.02). No cases of DCS or intra-pulmonary shunt were observed during or following post-dive exercise. DISCUSSION: These results suggest that post-dive strenuous exercise after a single field dive reduces post-dive gas bubble formation in well-trained military divers. Additional findings are needed for normal sports divers.