MRI of the heart: morphological and functional aspects

The performances of cardiac magnetic resonance imaging have been recently improved by the possibility of obtaining functional information by means of gradient echo sequences. Cavity volumetry and wall thickness and mass measurements are now possible. Ultrarapid sequences are useful for the analysis of myocardial perfusion and methods for measuring blood flow and temporal labelling of the ventricular wall open up new prospects for functional evaluation of the heart. In clinical practice, MRI can be useful for the exploration of cardiac parietal and intracavitary masses, constrictive pericarditis, hypertrophic and restrictive cardiomyopathy and cardiac malformations. Assessment of valvular and coronary heart disease is based on new techniques and is currently under evaluation.     

Medical aspects of fasting

Immunity to diphtheria and tetanus was determined in serum samples from 108 blood donors. Antitoxin concentration was evaluated by ELISA assay. 65% of donors were protected to diptheria and 100% to tetanus. Significant trend of decreasing immunity was observed with increasing age.     

Mammalian parathyroids: morphological and functional implications

Fixation with aldehydes is achieved either by immersion or perfusion. The parenchyma of parathyroid glands fixed by immersion consists of dark cells containing a lot of membranes of these organelles which are concerned with hormone secretion, light cells which are poor in these organelles, intermediate forms between the two, and multinuclear syncytial cells. They have been attributed to represent different functional stages of secretory activity, the dark cell being in an active form, the light cell in a resting form. Studies of the parathyroids of mice, rats, rabbits, cats, dogs, pigs, cattle, sheep, goats, and horses employing various fixation protocols clearly demonstrate that light cell variants and multinuclear syncytial cells are formed during improper immersion fixation as a result of membrane disintegration. Parathyroids fixed by perfusion or by immersion in an appropriate fixation medium comprise only one cell type which correspond to the dark chief cell. Parathyroid cells are polar cells bearing some of the rough endoplasmic reticulum in the basal pole, the rest of it, the Golgi complex, and secretory granules in the apical pole. The secretory product is released by exocytosis at the apicolateral domain of the plasma membrane into the intercellular space. Secretory activity can be altered experimentally, leading to drastic changes in the amount of cell membrane related to hormone synthesis, intracellular transport, exocytic release, and secretion coupled membrane retrieval. The sensitive reaction of parathyroid cells to both the mode of fixation and to fixation media demands careful evaluation of the fixation protocol. This and the polarity of parathyroid cells have to be borne in mind for estimating secretory activity on the basis of morphological criteria.     

Offside decisions by expert assistant referees in association football: Perception and recall of spatial positions in complex dynamic events.

This study investigated the offside decision-making process in association football. The first aim was to capture the specific offside decision-making skills in complex dynamic events. Second, we analyzed the type of errors to investigate the factors leading to incorrect decisions. Fédération Internationale de Football Association (FIFA; n = 29) and Belgian elite (n = 28) assistant referees (ARs) assessed 64 computer-based offside situations. First, an expertise effect was found. The FIFA ARs assessed the trials more accurately than the Belgian ARs (76.4% vs. 67.5%). Second, regarding the type of error, all ARs clearly tended to raise their flag in doubtful situations. This observation could be explained by a perceptual bias associated with the flash-lag effect. Specifically, attackers were perceived ahead of their actual positions, and this tendency was stronger for the Belgian than for the FIFA ARs (11.0 vs. 8.4 pixels), in particular when the difficulty of the trials increased. Further experimentation is needed to examine whether video- and computer-based decision-making training is effective in improving the decision-making skills of ARs during the game. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immunologic, functional, and morphological characterization of three new human small intestinal epithelial cell lines

BACKGROUND & AIMS: Epithelial cell cultures can be used for the study of epithelial cell biology, although human small intestinal cultures have not been available to date. The aim of this study was to characterize three cell lines derived from normal human duodenum. METHODS: Cells were cultured from tissue fragments obtained from endoscopic biopsy specimens and characterized with respect to morphology and cytokine gene expression and for the presence of vectorial transport. RESULTS: All cell lines grew as polarized continuous monolayers and were mostly cuboidal in shape but were not immortalized. Cells showed junctional complexes and sparse microvilli. All cell lines showed cytokeratins and mucin antigen but not chromagranin and messenger RNA for epidermal growth factor, interleukin 6, and vascular cell adhesion molecule 1. Disaccharidase activities were low and correlated with the low proportion of cells (1%-10%), showing positive immunocytochemistry for sucrase. Monolayer resistance varied from 30 to 200 ohms. One monolayer (BN) consistently showed secretion in response to forskolin (10 micromol/L), which could b inhibited by chloride-free buffer and apical addition of the chloride channel blocker diphenylamine decarboxylate. No monolayer had evidence of glucose transport. CONCLUSIONS: These three nonimmortalized lines show morphological, phenotypic, and transport characteristics of crypt-like intestinal epithelial cells. The pattern of messenger RNA expression suggests a growth-promoting and immunomodulatory role.     

Medical legal aspects of clinical monitoring

Modern laboratory technology has spawned a plethora of techniques for measuring and monitoring drug concentrations and body constituents; but the availability and frequent over-use of these determinations, some of which are exotic and require specialized personnel and expensive apparatus have further escalated the already high cost of medical care in several ways. The specter of medical malpractice suits has compelled the physician to practice defensive medicine including ordering unnecessary monitoring procedures, particularly for drug levels. Further impetus has been superadded by the courts and state legislatures; for example, phenylketonuria (PKU) determinations are mandatory in almost all states. Court rulings have held that "common knowledge" not expert testimony, may be all that is necessary to hold the doctor culpable for not ordering a test; nor is expert testimony necessarily required if the Physicians Desk Reference (PDR) or drug company insert recommends that certain tests or monitoring procedures be performed and the doctor fails to comply. (PSRO) programs will force further conformity, leave less to the discretion of the physician and place the government in an ever more regulatory role. Professional societies should take cognizance of the impropriety and danger of the government dictating diagnosis and treatment and should launch a vigorous program to scrutinize pending regulatory legislation and to make official and informed representations to appropriate legislators.     

Medical and psychological aspects of irritable bowel syndrome

To engineer an a non-islet cell capable of glucose-stimulated insulin secretion, a chinese hamster ovary cell line (CHO) was transfected with a mammalian expression vector carrying the human insulin cDNA (pCB/hINS). More proinsulin than insulin was released daily by the stably transformed cell line (CHO-INS). Examination of acid-ethanol extracts confirmed that both insulin and proinsulin were stored. Immunohistochemical analysis of the cells also showed that (pro)insulin was stored. Unlike beta cells, CHO-INS cells did not secrete insulin in response to glucose. To investigate this lack of effect, we examined whether transfection of GLUT2 cDNA, which is ordinarily not expressed in CHO-INS cells, would confer glucose-stimulated insulin secretion. Consequently, we have demonstrated that glucose regulated insulin release occurs in the CHO-INS-GLUT2 cell line and that glucose potentiates the insulin secretory response to non-glucose secretagogues.     

New model of renal warm ischaemia-reperfusion injury for comparative functional, morphological and pathophysiological studies

BACKGROUND: Renal warm ischaemia-reperfusion injury is pertinent to vascular and transplant surgery. While established models provide functional and morphological data the authors wanted to be able to correlate this with the underlying pathophysiology at any chosen time point, thus allowing future interventional effects on reperfusion injury to be evaluated. METHODS: In a rodent model bilateral renal warm ischaemia (15-60 min) and then reperfusion (20 or 80 min) before nephrectomy allowed for analysis of early reperfusion pathophysiology. The remaining kidney provided functional data (glomerular filtration rate (GFR)) at days 2 and 7 before nephrectomy for late analysis and morphology using a new grading system. RESULTS: Acceptable survival rate (ten of 12 animals) was seen with up to 45 min of warm ischaemia. Renal function was impaired at day 2 following 30-60 min of warm ischaemia (P< 0.01) and day 7 in the 45- and 60-min groups (P < 0.05 and P < 0.01 respectively). Strong correlation existed between duration of ischaemia and GFR at day 2 (r2=0.88) and day 7 (r2=0.95). Histological damage in the cortical tubules was evident in the 45- and 60-min groups (P< 0.01). CONCLUSION: This new model allowed comparative functional, morphological and pathophysiological studies while minimizing the number of animals required. Overall 45 min of warm ischaemia gave significant, recoverable injury and is recommended for investigating renal reperfusion injury.     

Growth of macrophage colonies from normal canine peripheral blood: morphological, cytochemical and functional parameters

Canine macrophage colonies were grown at high colony-forming efficiencies (average of 4.5 macrophage colonies/10(4) mononuclear cells plated) from gradient-separated peripheral blood mononuclear cells. The colonies were first observed on day 5 of the culture period, reached maximum numbers between days 10-14, and differed kinetically from CFU-GM colonies. Colony cells had typical macrophage morphology at the cellular and ultrastructural levels, were nonspecific-esterase positive, specific-esterase negative, and were actively phagocytic. Colony growth in semisolid cultures and 3H-TdR incorporation in liquid cultures occurred following stimulation with rabbit anti-canine immunoglobulin antisera (anti-Ig), anti-bovine serum albumin and normal rabbit serum. Addition of 2-mercaptoethanol (2-Me) to stimulated cultures significantly enhanced the proliferative response. A maximal response was obtained using anti-IgM and 2-ME. Preincubation of anti-Ig with goat anti-rabbit IgG or purified canine immunoglobulin in the presence or absence of 2-ME significantly reduced the proliferative response, suggesting the presence of both specific and nonspecific components of stimulation. The growth of canine macrophage colonies from peripheral blood provides a method for non-invasive, sequential and kinetic studies of macrophage progenitor cells in large animals.     

Medical and biological aspects of artificial gravity: animal studies

In the review there analyzed the results of ground-based studies of rotation effects (at a gravity value near 1 g) on the animals, the experimental findings to determine a minimum effective value of artificial gravity as well as the data of biosatellite experiments. The major trends of animal studies in the artificial gravity area is presented.     

Clinico-radiological and functional aspects of respiratory syndromes caused by collagen diseases

The clinical and radiological features in 100 patients with collagen diseases (rheumatoid arthritis, lupus, sclerodermia, dermatomyositis, and panarteritis nodosa) were compared with respiratory performance. 56 patients were drawn from the series of Pende et Al. and 44 from a personal series. The results are set out in tables and graphs. It was found that lung lesions due to collagen disease have no special clinical and radiological features. Respiratory performance is that of a restrictive syndrome that gradually progresses from A.R. to E.S., S. and P.M., accompanied by obstruction of the large airways, as shown by hyperinsufflation in sclerodermia and reduced specific conductance in rheumatoid arthritis.