Polyp Sensitivity

The first problem was partly addressed by PiCKHARDT et al. (PiCKHARDT et al. 2003), who showed that, based on 1233 asymptomatic patients, CTC could have a high by-polyp sensitivity of 93.9% for polyps >8 mm. This was superior even to that of optical colonoscopy. However, other large trials showed much lower sensitivity a prospective trial on 703 asymptomatic patients reported by Johnson, et al. OoHNSON et al. 2003a), a multicenter trial at 8 hospitals on 314 patients, also reported by Johnson et al. (Johnson et al. 2003b), a prospective multicenter trial at 9 hospitals on 615 patients by Cotton et al. (Cotton et al. 2004), and the most recent prospective multicenter trial at 15 hospitals on 617 patients by Rockey et al. (Rockey et al. 2005). Therefore, a larger clinical trial with the state-of-the art CT scanner and interpretation method needs to be conducted to address the first concern. 

Among the studies published in peer-reviewed journals that describe a full CAD scheme, the CAD scheme developed at the University of Chicago yielded a 95% by-polyp sensitivity, with an average of 1.5 false positives per patient (0.7 false positives per... 

The CAD system at the University Hospital Gast-huisberg achieved an 80% hy-polyp sensitivity, with 8.2 false positives per patient (4.1 false positives per data set), based on 18 patients, with 15 polyps 5 mm in 9 patients (Kiss et al. 2002). In this study, fecal tagging was used for most of the cases. A group at Stanford reported a 100% sensitivity with 7.0 false positives per data set (only the supine data set of each patient was used) based on 8 patients that included a total of 7 polyps >10 mm in 4 patients (Pair et al. 

Three years after introduction of aspirin into therapy, Hirschberg in Poznan, now in Poland, described the first case of a transient, acute angioedema/urticaria, occurring shortly after ingestion of aspirin. Reports of anaphylactic reactions to aspirin soon followed. The other major type of adverse reaction, acute bronchospasm, was described in the second decade of the 20th century. In 1920, Van der Veer reported the first death due to aspirin. The association of aspirin sensitivity, asthma and nasal polyps was first recorded by Widal in 1922. This clinical entity, later named the aspirin triad was popularized in 1968 by Samter and Beers [3], who presented a... 

Genetic factors cannot explain the recent rapid rise in asthma prevalence. Asthma appears to require both genetic predisposition and environmental exposure. Many patients with occupational asthma develop the disease late in life upon exposure to specific allergens in the workplace. Environmental influences in utero or in infancy may contribute to the development of asthma. Maternal smoking during pregnancy or exposure to secondhand smoke after birth increases the risk of childhood asthma.3 Adult-onset asthma is not uncommon and may be related to atopy, nasal polyps, aspirin sensitivity, occupational exposure, or a recurrence of childhood asthma. 

Acute and chronic sinusitis can also aggravate asthma, and antibiotic therapy of sinusitis may improve asthma symptoms.3 Nasal polyps are associated with aspirin-sensitive asthma, and adult patients with nasal polyps should be counseled against using non-steroidal anti-inflammatory medications.1,3... 

Aspirin desensitization is useful in diseases where low-level antiplatelet action is needed and in the care of patients with aspirin sensitivity and intractable nasal polyps. Lysine aspirin availability in Europe allows desensitization by inhalation at... 

Obelin is a Ca2+-activated bioluminescent photoprotein that has been isolated from the marine polyp Obelia longissima. Binding of calcium ions determines a luminescent emission. The protein consists of 195 amino acid residues [264] and is composed of apoobelin, coelenterazine, and oxygen. As aequorin, it contains three EF-hand Ca2+-binding sites and the luminescent reaction may be the result of coelenterazine oxidation by way of an intramolecular reaction that produces coelenteramide, C02, and blue light. As for aequorin, the luminescent reaction of obelin is sensitive to calcium and the protein was used in the past as an intracellular Ca2+ indicator. More recently, the cloning of cDNA for apoobelin led to the use of recombinant obelin as a label in different analytical systems. 

NSAID hypersensitivity Because of potential cross-sensitivity to other NSAIDs, do not give these agents to patients in whom aspirin or other NSAIDs have induced symptoms of asthma, rhinitis, urticaria, nasal polyps, angioedema, bronchospasm. 

The more sensitive and convenient method of PolyP detection in situ is fluorescence microscopy using fluorochromes of the type 4/,6/-diamino-2-phenylindole.2HCl (DAPI), which is commonly used for DNA detection. At a high concentration (50 mg ml 1), it also stains PolyP granules and lipid inclusions (Allan and Miller, 1980 Tijssen et al, 1982 Streichan et al, 1990). DAPI-DNA fluorescence is blue-white, while DAPI-PolyP and DAPI-lipid fluorescence is yellow. The lipid fluorescence is weak and fades in a few seconds, while the PolyP granules appear bright yellow, thus allowing discrimination of the above types of cell inclusions (Streichan et al, 1990). 

Therefore, the availability of purified enzymes specific to PolyPs allowed the development of rapid, sensitive and definitive assays. It should be noted, however, that PolyPs in biological samples may not be effectively hydrolysed by exopolyphosphatase or be available for polyphosphate kinase (Sethuraman et al, 2001). 

One of the characteristics of protein calcium channels is their sensitivity to ablock by transition metal cations. Lanthanum is a particularly potent blocker. It is suggested that permeant and blocking ions compete for the common binding sites in the channels. The PolyP-PHB channel complexes are also blocked by transition metal cations in a concentration-dependent manner. A nearly complete block of single-channel currents was observed in the synthetic complexes at concentations > 0.1 mM La3+ (0.1 % of Ca2+) (Das et al., 1997). Evidently, PHB-PolyP complexes are versatile ion carriers whose selectivities may be modulated by small adjustments of the local pH. The results may be relevant to the physiological function of PHB-PolyP channels in bacteria and the role of PHBs and PolyPs in the Streptomyces lividans potassium channel (Das and Reusch, 2001). 

There are other examples of the influence of PolyPs on the expression of some genes omitting rpoS. If the level of cellular PolyP in E. coli was reduced to a barely detectable concentration by overproduction of exopolyphosphatase (Shiba et al., 1997), the cells were more sensitive to UV or mitomycin C than the control cells. PolyP accumulation was observed after treatment with mitomycin C, whereas the PolyP level was below the detectable level... 

There is an example of another effect of mutation of the vacuolar PolyP. S. cerevisiae, with a defect of the SPT7 gene, became less sensitive to nickel and had a highly elevated amount of PolyPs in the vacuoles (Nishimura et al., 1999). 

Had it not been for the remarkable increase in their numbers when the cells are made genetically transformable and the sensitivity of the fluorescence assay with NPN, it is likely they would have remained undetected for many years to come (Figure 24A). It was the striking correlation between PHB/polyP concentrations and transformation efficiencies in A. vinelandii, B. subtilis, and E. colt that led Reusch et al 22,23,25 to postulate that the complexes play a role in DNA transmembrane transport (Figure 24B). Here we will briefly consider the experimental and structural evidence in support of this hypothesis, and speculate on a mechanism by which PHB/polyP may be used for DNA transmembrane transport. 

People with asthma may be particularly sensitive to acetylsalicylic acid, which may be given alone or as a constituent of a combination medicine. The association between aspirin sensitivity, nasal polyps, and rhinitis in asthma is well known. 

Aspirin sensitivity or intolerance occurs in 4% to 20% of aU asthmatics." The frequency of aspirin-induced bronchospasm increases with age. Patients older than 40 years have a frequency approximately four times that of patients younger than 20 years." The frequency increases to 14% to 23% in patients with nasal polyps." Women predominate over men, and there is no evidence for a genetic or familial predisposition."... 

All aspirin-sensitive asthmatics do not fit the classic aspirin triad picture, and not all patients with asthma and nasal polyps develop sensitivity to aspirin. In most cases, aspirin-sensitive asthmatics are clinically indistinguishable from the general population of asthmatics except for their intolerance to aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). Aspirin-induced asthmatics are not at higher risk of having fatal asthma if aspirin and other NSAIDs are avoided. ... 

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