Preliminary core set of domains and reporting requirements for longitudinal observational studies in rheumatology

The minimized energy mapping of annexin V Trp-187 chi1 x chi2 isomerization supports the existence of two preferential rotameric orientations of the Trp side chain upon annexin V binding to membranes, in agreement with the time-resolved fluorescence results. They correspond to the perpendicular trans (-173 degrees, 73 degrees) and g- (-71 degrees, 83 degrees) rotamers and represent 59 and 28% of the population, respectively. The analysis of their local environment makes it possible to assign the trans rotamer to the long component and the g- rotamer to the short component of the biexponential fluorescence decay. The orientation of these rotamers relative to the protein core suggests a dual role for Trp-187, which might be involved both in the interaction with the phospholipid bilayer and in the formation of the annexin V 2-D array at the surface of the membrane.     

Automated detection of bolus arrival and initiation of data acquisition in fast, three-dimensional, gadolinium-enhanced MR angiography

Automatic triggering of magnetic resonance (MR) angiography with detection of a contrast material bolus was evaluated. Signal intensity changes with time were tracked in a prescribed tracking or monitoring volume by a parallel signal processing unit that automatically started data acquisition once user-defined thresholds were exceeded. This technique, referred to as MR Smartprep, was reliable and avoided the inconsistencies of manual timing.     

Multiple symmetric lipomatosis in the Chinese: ultrasound, CT and MR imaging

We report four cases of multiple symmetric lipomatosis in the Chinese population. We believe that multiple symmetric lipomatosis in the Chinese is not uncommon and may be related to the increasing incidence of alcoholism. The ultrasound appearances of these lipomatous masses are presented for the first time. Heterogeneous echogenic masses with fine fibrous strands that insinuate around fascial planes, lymph nodes and vascular tissues are typical findings. Unlike diseases affecting the Western population, multiple symmetric lipomatosis in the Chinese appears to be limited to the head and neck.     

Lifestyle, gender and occupational status as determinants of dental health behavior

A 23-year-old patient suffered from episodic angioedema of the face and neck, accompanied by diarrhea and abdominal pain. Additionally, the patient had bronchial asthma, recurrent nasal polyps and allergic rhinoconjunctivitis. Blood examination revealed leucocytosis with eosinophilia. Histological studies showed eosinophilic infiltrates in the skin and the gastrointestinal mucosa. Allergic food reactions and parasites were ruled out. With systemic corticosteroid treatment, the clinical symptoms and the eosinophilia disappeared. This case shows some parallels to previously described syndromes (eosinophilic gastroenteritis, Samter's syndrome, episodic angioedema with eosinophilia), but to the best of our knowledge this combination of symptoms has not yet been reported.     

Abdominal compartment syndrome

PURPOSE: Two cases of abdominal compartment syndrome are described and the pathophysiology associated with it is reviewed. CLINICAL FEATURES: The first patient was a 46-yr-old man who sustained extensive blunt abdominal injuries following a fall. The second was a 54-yr-old man involved in a motor vehicle accident with blunt abdominal trauma. In both cases, the patients developed an extremely tense abdomen, increasing peak inspiratory pressures, hypercarbia and oliguria. Both demonstrated improvement in cardiac performance and ventilatory variables following an emergency decompressive celiotomy. CONCLUSION: Abdominal compartment syndrome results in impairment of organ function secondary to increased intraabdominal pressure. These patients require emergency decompressive celiotomy to relieve the symptoms. However, the incidence of intractable asystole and hypotension during this procedure is high and vigilance must be maintained during the release of the increased intraabdominal pressure.     

Vaccinia DNA topoisomerase I: evidence supporting a free rotation mechanism for DNA supercoil relaxation

The Vaccinia type I topoisomerase catalyzes site-specific DNA strand cleavage and religation by forming a transient phosphotyrosyl linkage between the DNA and Tyr-274, resulting in the release of DNA supercoils. For type I topoisomerases, two mechanisms have been proposed for supercoil release: (I) a coupled mechanism termed strand passage, in which a single supercoil is removed per cleavage/religation cycle, resulting in multiple topoisomer intermediates and late product formation, or (2) an uncoupled mechanism termed free rotation, where multiple supercoils are removed per cleavage/religation cycle, resulting in few intermediates and early product formation. To determine the mechanism, single-turnover experiments were done with supercoiled plasmid DNA under conditions in which the topoisomerase cleaves predominantly at a single site per DNA molecule. The concentrations of supercoiled substrate, intermediate topoisomers, and relaxed product vs time were measured by fluorescence imaging, and the rate constants for their interconversion were determined by kinetic simulation. Few intermediates and early product formation were observed. From these data, the rate constants for cleavage (0.3 s(-1)), religation (4 s(-1)), and the cleavage equilibrium constant on the enzyme (0.075) at 22 degrees C are in reasonable agreement with those obtained with small oligonucleotide substrates, while the rotation rate of the cleaved DNA strand is fast (approximately 20 rotations/s). Thus, the average number of supercoils removed for each cleavage event greatly exceeds unity (delta n = 5) and depends on kinetic competition between religation and supercoil release, establishing a free rotation mechanism. This free rotation mechanism for a type I topoisomerase differs from the strand passage mechanism proposed for the type II enzymes.     

Comparison of two oral evacuants (Citromag and Golytely) for bowel preparation before barium enema

Oral regimens for bowel preparation before barium enema examination are routinely used because of their convenience and simplicity, rather than the traditional method of colonic wash-out. We performed a prospective study comparing the side-effects and efficacy of two commonly used oral bowel evacuants (Citromag and Golytely) for bowel preparation before barium enema examination in 102 patients. The side-effects associated with the agents were assessed by analysing a questionnaire completed by the patients. There was no significant difference in the side-effects between the two agents although more patients taking Golytely (45.5%) deemed its taste unacceptable than those taking Citromag (25.9%). The results of the bowel preparation were assessed by two independent radiologists giving scores on the amount of faecal residue and the quality of mucosal coating. The amount of faecal residue was less in the Golytely group (p < 0.05). The quality of mucosal coating by barium was also better in the Golytely group than the Citromag group (p < 0.05).     

Measurements of phantom scatter factors for small field sizes in high energy x rays

An alternate method to measure the phantom scatter factor in small fields is provided for high energy photon beams. The measurement technique is based on the density scaling theorem described by O'Connor [Phys. Med. Biol. 1, 352-369 (1957)]. The phantom scatter factor (Sp) is measured in balsa and cedar wood to give effective field sizes in 3 x 3 to 0.5 x 0.5 cm2 water. The extrapolated zero area phantom scatter factor from the average data of balsa and cedar is 0.45. This indicates that the variation of output is largely due to a sharp decrease in the phantom scatter factor for small field sizes.