Placental malaria. I. Pathological classification

Pregnant women are more likely to contract malaria than their non-pregnant counterparts. The aim of this study was to develop a simple classification system for the histopathological diagnosis of placental malaria infection applicable to placentas collected in field conditions. The placentas were classified into four groups depending on the presence and disribution of parasites and malaria pigment: active infection, active-chronic infection, past-chronic infection, not infected. The frequency of parasitized placentas (26.4%) was in keeping with the prevalence of placental parasitaemia documented in epidemiological studies. An additional 29.8% placentas showed pigment in fibrin only, indicating pastchronic infection. Chronic placental malaria infection was most common in primigravidae, possibly reflecting ineffective clearance of parasites from the placenta. Seasonal fluctuations between infection categories support progression of placental infection with delayed clearance of pigment from fibrin. The proposed classification system has allowed diagnosis of different categories of placental malaria infection by two independent observers. A stadardized method of diagnosis may enhance understanding of placental pathology and reduced birth weight in malaria infection during pregnancy.     

(iii) Minimal invasive techniques in the management of tibial plateau fractures

Intra-articular fractures of the proximal tibia present a wide spectrum of injury patterns with associated soft tissue injury. The last two decades have seen the techniques of management evolve from extensive open reduction and rigid internal fixation to arthroscopy-assisted minimal invasive surgery (MIS) and biologically benign internal fixation. The ultimate aim is to prevent the occurrence of late degenerative arthritis. This could be achieved in selected patients using minimal invasive surgery, which offers the advantages of better visualisation and management of intra-articular soft tissue injuries, confirmation of fracture reduction viewed from the joint surface, faster rehabilitation and fewer wound complications.     

RETROPERITONEAL SCHWANNOMA: A CASE SERIES AND REVIEW

Schwannomas account for only a small percentage of retroperitoneal tumours. Presentation is typically varied and non-specific and pre-operative diagnosis is difficult. Herein are described five cases of retroperitoneal schwannoma. Presentation was varied, ranging from abdominal pain, abdominal mass, obstructed labour or an incidental finding. All patients had either an abdominal computed tomography scan and/or ultrasound performed. Pre-operative biopsy either by fine needle aspiration (in one patient) or core biopsy in two patients was unhelpful. In four patients with smaller tumours, complete excision was possible with no apparent long-term morbidity and no clinical evidence of recurrent tumour with follow up from 3.5 months to 11 years. For the largest tumour, complete surgical excision was not attempted as it would have entailed significant morbidity.     

Détermination de la tortuosité pour la détection des rétinopathies vasculaires sur les images d''angiographie rétinienne

Les rétinopathies vasculaires peuvent être accompagnées d'une modification de la forme des vaisseaux. Les patients atteints courent le risque de perdre la vue. Jusqu'ici, les méthodes utilisées par les ophthalmologistes pour analyser ces modifications sont qualitatives. Nous proposons une méthode nouvelle d'analyse de la tortuosité des vaisseaux de la rétine en vue d'élaborer par la suite un outil d'aide au diagnostic des rétinopathies vasculaires. La première étape de la méthode est une représentation symbolique de la structure vasculaire de la rétine. La deuxième étape appelée reconstitution 2D est la classification des entités vasculaires en gros vaisseaux (artères ou veines) et en petits vaisseaux (artérioles ou veinules) en utilisant la moyenne du diamèetre et du niveau de gris des segments de vaisseau comme paramètres discriminants. La dernière étape consiste à calculer l'excentricité des vaisseaux pour décrire leur tortuosité. Pour s'assurer de la capacité de l'excentricitéà décrire les petites modifications de forme, un second paramètre a été défini à titre comparatif. Les résultats obtenus permettent de quantifier les modifications de forme des vaisseaux.     

Clinical course and outcome of cycloid psychotic disorder: a three-year prospective study

The course and outcome of cycloid psychotic disorder was explored by means of a prospective three-year follow-up of a sample of patients fulfilling the diagnostic criteria for the disorder provided by Perris & Brockington, compared to patients with a diagnosis of affective or schizoaffective disorder. The most striking difference between cycloids and affectives was the lack of manic episodes during the follow-up period in the former group. Moreover, the mean age at onset was lower in cycloids. No difference between these patient groups was observed with regard to outcome. Compared to schizoaffectives, cycloids showed several differences in the clinical picture during the index episode, and their symptomatological pattern was more consistent from one episode to another during the follow-up. Moreover, the outcome of cycloids was significantly more favourable than that of schizodepres-sives.     

关于卫生监督医疗纠纷类图书归类探析

指出第四版《中图法》中有关卫生监督、医疗事故、医疗纠纷等类目中存在的一些问题和不足,并提出具体改进措施和分类建议。     

A Bayesian approach to subvoxel tissue classification in NMR microscopic images of trabecular bone

NMR microscopy is currently being used as an investigational tool for the evaluation of micromorphometric parameters of trabecular bone as a possible means to assess its strength. Since, typically, the image voxel size is not significantly smaller than individual trabecular elements, partial volume blurring can be a major complication for accurate tissue classification. In this paper, a Bayesian segmentation technique is reported that achieves improved subvoxel tissue classification. Each voxel is subdivided either into eight subvoxels twice the original resolution, or up to four subvoxels along the transaxial direction and the subvoxels optimally classified as either bone or marrow. Based on a statistical model for partial volume blurring, the likelihood for the number of marrow subvoxels in each voxel can be computed on the basis of its measured signal. To resolve the ambiguity of the location of the marrow subvoxels, a Gibbs distribution is introduced to model the interaction between the subvoxels. Neighboring subvoxel pairs with the same tissue label are encouraged, and pairs with distinct labels are penalized. The segmentation is achieved by maximizing the a posteriori probability of the label image using the block ICM (iterative conditional mode) algorithm. The potential of the proposed technique is demonstrated in real and synthetic NMR microscopic images.