Choledochocele of the common bile duct

The eighth report case of choledochocele is described. This lesion is a cyst communicating with the terminal portion of the common bile duct. It is characteristically lined with duodenal mucosa and is probably a form of duplication of the duodenum. The surgical treatment is marsupialization of the cyst to the interior of the duodenum.     

Non-Hodgkin's lymphoma

Attention is being directed at increasing the intensity of therapy as a means of improving the results of primary therapy for non-Hodgkin's lymphoma. There is increasing evidence that the use of high-dose consolidation therapy followed by autologous hematopoietic rescue in first remission improves survival in high-risk patients. There is also evidence from randomized trials that transplantation for relapsed patients improves survival compared with conventional salvage chemotherapy. Phase II trials of radiolabeled antibody therapy are providing promising results. There is still no definitive evidence that any treatment of advanced low-grade lymphoma prolongs survival, although the use of allogeneic bone marrow transplantation is under investigation. Treatment designed to eradicate Helicobacter pylori can cause regression in approximately 50% of patients with gastric lymphomas of mucosa-associated lymphoid tissue, although long-term follow-up information is lacking. The results of treatment for mantle cell lymphoma are poor and there is no consensus on management. Most trials of primary central nervous system lymphoma are employing systemic chemotherapy with drugs that penetrate the blood-brain barrier in addition to radiation.     

Androgen metabolism and prostate cancer: establishing a model of genetic susceptibility

The prostate is an androgen-regulated organ, which has led to long-standing interest in the role of androgens in prostate carcinogenesis. Although evidence of a hormonal etiology for prostate cancer is strong, it is almost entirely circumstantial. Much of the problem in proving a causal relationship relates to the continued difficulties in reliably measuring human tissue-specific exposure to endogenous steroid hormones. The international and racial-ethnic variations in prostate cancer incidence, combined with the effects of migration on risk patterns, have suggested that whereas environmental factors are likely to be important, genetic factors might also play a central role in determining prostate cancer risk. We are developing a polygenic model of prostate carcinogenesis focused around a series of genes involved in androgen biosynthesis and androgen activation, transport, and metabolism in the prostate. In this developing model, we have initially targeted four genes based on three main criteria: (a) all encode products that play important roles in inducing androgen stimulation in the prostate; (b) all are polymorphic; and (c) all show substantial allelic variation in the polymorphic marker among the racial-ethnic groups of greatest interest in terms of prostate cancer risk. In addition to studying how the polymorphic markers of interest are related to prostate cancer development within and between racial-ethnic groups, we are concurrently evaluating whether genotypic variations correlate in the anticipated direction with biochemical parameters in vitro and in vivo. We summarize the development of this model and the state of knowledge related to each of the genes comprising the current model. We discuss the extent to which the current model can explain demographic variation in prostate cancer risk as well as the potential for future expansion of the model to incorporate environmental risk factors as well as additional genes. The model, when fully developed, can potentially provide a basis for targeting populations for screening interventions and/or preventive strategies aimed at the multigene products or at the genes themselves.     

Trace elements and protein-calorie malnutrition in the Fès area (Morocco)

Copper and selenium are essential micronutrients for development and growth as well as being necessary for the immune system and as an antioxidant defense. These trace elements present a variable distribution according to geographic regions. Several studies have shown reduced serum copper and selenium levels, as well as the activity of erythrocyte copper-zinc superoxide dismutase (SOD) and selenium-glutathione peroxidase (GPX) in protein-calorie malnutrition (PCM). The aim of this study was to evaluate the erythrocyte enzymatic activity depending on copper or selenium and the levels of these elements in serum. Fifty-six Moroccan children between the age of 6 to 60 months were selected, then divided into 20 control group children and 36 patients suffering from PCM (15 mildly malnourished and 21 severely malnourished). The malnourished group showed a significant decrease of selenium and copper levels that was related to the severity of malnutrition. Serum selenium decreased more than serum copper. No differences were noted between the groups in erythrocyte GPX activity, whereas SOD activity showed more discrepancy than in the copper levels in malnutrition. Serum copper or ceruloplasmin levels could be used as indicators of the severity of malnutrition, whereas the selenium levels could be used as indicators of the nutritional status.     

Cytomegalovirus DNA can be detected in peripheral blood mononuclear cells from all seropositive and most seronegative healthy blood donors over time

1. The purpose of this study was to assess the potential of various preservation solutions, orginally designed for solid organs, to protect muscle function during cold storage. 2. The soleus (SOL) and the cutaneous trunci (CT) muscle from the rat were isolated and stored for 2, 4 or 8 h at 10 degrees C. The solutions used, listed in order from an intracellular to an extracellular-like composition, were: University of Wisconsin (UW), Euro-Collins (EC), HTK-Bretschneider (HTK), reversed St. Thomas' Hospital (ST2) and Krebs-Henseleit (KH). After cold storage, the muscles were tested by direct electrical stimulation to obtain the maximum twitch tension (Pt) and the maximum tetanus tension (P0). Subsequently, the muscles were prepared for morphological analysis. 3. In general, storage at 10 degrees C caused a gradual decrease of Pt and P0 with time. After 8 h of storage in the extracellular-like solutions KH and ST2, the P0 was about 50% (SOL) and 35% (CT) of control. Eight hours of storage in intracellular-like solutions resulted in a P0 of 50% of control for HTK, in a P0 of 40% (SOL) and 67% (CT) for UW, but in a P0 of 5% (SOL) and 26% (CT) for EC. These findings corresponded well with the morphological observations. 4. It is concluded that the effects of 10 degrees C storage on skeletal muscle function are not predominantly determined by the intra- or extracellular-like composition of the solutions used. Both UW and HTK were most effective (P0 > 50% of control) in preserving muscle function.     

Effect of adaptation to high altitude hypoxia on fixation of temporary connections

Parameters of preservation of conditioned defensive reflexes elaborated in one combination and of reflexes elaborated in many combinations in a T-maze varied as a function of time in animals preliminarily adapted to hypoxia and in control ones. Adaptation to altitude hypoxia raised the degree and duration of preservation of temporary connections and did not influence the course of conditioning. The degree of preservation in animals adapted to hypoxia was enhanced both during continued adaptation and in ten to twenty days after its cessation. It is probable that adaptation considerably intensifies the process of fixation of temporary connections. It is suggested that the effect results from activation of the synthesis of nucleic acids and proteins in the brain, due to adaptation to altitude hypoxia.     

The complex-shaped ‘perforated’ synapse,a problem in quantitative stereology of the brain

Failure to appreciate the consequences for stereological work of the simultaneous presence of complex-shaped perforated and disc-like non-perforated synapses in brain tissue results in underestimation of synaptic profile length and overestimation of synaptic density when measured in randomly selected ultrathin E-PTA slices. This problem can be solved by using serial slices and a calculation method which makes no assumptions about synaptic size and shape. A three-dimensional reconstruction is unnecessary.     

Computation of the factorized error covariance of the differencebetween correlated estimators

A state estimation problem where some of the measurements may be common to two or more data sets is considered. Two approaches for computing the error covariance of the differences between filtered estimates (for each data set) are discussed. The first algorithm is based on postprocessing of the Kalman gain profiles of two correlated estimators. It uses UD factors of the covariance of the relative error. The second algorithm uses a square root information filter applied to relative error analysis. In the absence of process noise, the square root information filter is computationally more efficient and more flexible than the Kalman gain (covariance update) method. Both the algorithms (covariance and information matrix based) are applied to a Venus orbiter simulation and their performances are compared