Balloon extraction of esophageal foreign bodies in children

A study to determine the sensitivity, specificity, and positive and negative predictive values of several clinical diagnostic tests of subcutaneous Achilles tendon rupture was performed during a 13-year period. There were 174 patients with clinical diagnosis of unilateral complete subcutaneous Achilles tendon tear and 28 patients with unilateral suspected but no actual Achilles tendon tear. The following tests were used: palpation, calf squeeze, Matles, Copeland, and O'Brien. Palpation of the gap was the least sensitive clinical test with the patient awake (0.73), increasing to 0.81 when the test was performed under anesthesia; the Copeland and O'Brien tests showed a sensitivity of 0.8. Both the calf squeeze and Matles tests were significantly more sensitive than the other tests (0.96 and 0.88, respectively; 0.022 < P < 0.05). All tests showed a high positive predictive value, with no statistically significant difference between the various tests. In the 28 patients with no evidence of a subcutaneous Achilles tendon tear on imaging, the tests showed a high capability to detect that the Achilles tendon was intact (gap palpation specificity, 0.89; calf squeeze test specificity, 0.93; Matles test specificity, 0.85). Whichever tests were performed, at least two of them were positive for a subcutaneous tear of the Achilles tendon in all patients in this study.     

Prevalence of malnutrition in minors under 5 years of age in Tabasco

AIMS: Abdominal aortic aneurysms are characterised by changes in the extracellular matrix of the arterial media, in particular a reduction in elastin concentration. These changes are mediated by increased levels of endogenous matrix metalloproteinases (MMPs). Recently, calcium channel blockers have been shown to increase the proteolytic activity of MMP-2 secreted by vascular smooth muscle cells. It may therefore by hypothesised that calcium antagonists may potentiate the activity of MMPs in aneurysmal disease and thus accelerate AAA expansion. In this study, the ability of amlodipine--a calcium antagonist--to influence elastin degradation, was assessed in a previously described model of aneurysmal disease. METHODS: Porcine aortic segments (n = 8) were pre-incubated in exogenous pancreatic elastase for 24 h prior to culture in standard conditions for 6 days with 10 and 100 micrograms/l amlodipine. Control segments were cultured both with and without amlodipine and without elastase. At the termination of culture MMPs were extracted from the tissue and quantified by a combination of substrate gel enzymography and immunoblotting. The volume fractions of elastin and collagen were determined by stereological analysis of EVG stained sections. RESULTS: Gel enzymography demonstrated significantly increased MMP-9 activity in the amlodipine treated segments, median 4.218 vs. 2.809 arbitrary units (p < 0.01) and this elevated activity was reflected in a significant destruction of medial elastin 27.0 vs. 40.5% (p < 0.05). CONCLUSION: Therapeutic ranges of amlodipine significantly enhanced elastin degradation and potentiated MMP-9 activity within the aortic organ cultures.     

Evaluation of the standardized disk diffusion and agar dilution antibiotic susceptibility test methods by using strains of Neisseria gonorrhoeae from Tucumán, Argentina

At present, most Neisseria gonorrhoeae testing is done with beta-lactamase and agar dilution tests using common therapeutic agents. Generally, in bacteriological diagnosis laboratories in Argentina, study of antibiotic susceptibility of N. gonorrhoeae is based on beta-lactamase determination and agar dilution method using common therapeutic agents. The National Committee for Clinical Laboratory Standards (NCCLS) recently described a disk diffusion test that produces results similar to the reference agar dilution method for antibiotic susceptibility of N. gonorrhoeae. We obtained 57 gonococcal isolates from patients attending a clinic for sexually transmitted diseases in Tucumán, Argentina. Antibiotic susceptibility tests using agar dilution and disk diffusion techniques were compared. The established NCCLS interpretive criteria for both susceptibility methods appeared to be applicable to domestic gonococcal strains. The correlation between the minimum inhibitory concentration (MIC's) and the zones of inhibition was studied for penicillin, ampicillin, cefoxitin, spectinomycin, cefotaxime, cephaloridine, cephalexin, tetracycline, norfloxacin and kanamycin. Dispersion diagrams showed a high correlation between both methods, with a sensitivity of 89% and specificity of 91%.     

Differential superoxide anion generation by equine eosinophils and neutrophils

Equine eosinophils and neutrophils are believed to play an important part in the protection of horses against parasitic and bacterial invasion. Eosinophils may also play a key role in the pathogenesis of equine inflammatory conditions such as the allergic skin disease, insect hypersensitivity. The factors which stimulate the respiratory burst of equine eosinophils and neutrophils are poorly understood. The first aim of the present study was to determine the effects of the phorbol ester, phorbol myristate acetate (PMA), which is believed to activate intracellular protein kinase C, and opsonised particles of serum-treated zymosan (STZ), on the production of superoxide anions by equine eosinophils and neutrophils. Since histamine has been detected after antigen challenge in the skin of horses with insect hypersensitivity, the second aim was to establish the effects of this mediator on superoxide anion production by equine eosinophils and the receptor sub-type(s) that mediate histamine-induced responses. For comparison, responses of neutrophils from the same horses were also examined. PMA and STZ induced significant increases in superoxide anion generation by equine eosinophils and neutrophils. The estimated maximum (EMAX) superoxide anion production by eosinophils in the presence of PMA was significantly greater than that of neutrophils; the estimated concentration of PMA inducing 50% of the maximum response (EC50) by eosinophils was significantly less. The EMAX values for superoxide anion production by neutrophils in the presence of STZ were significantly greater than those for eosinophils. Histamine induced superoxide anion generation by equine eosinophils which was inhibited by the histamine-1 receptor antagonists chlorpheniramine and mepyramine, but not the histamine-2 and histamine-3 receptor antagonists, cimetidine and thioperamide, respectively. Histamine did not cause superoxide anion production by equine neutrophils. These studies demonstrate that equine granulocytes vary in their ability to produce a respiratory burst in the presence of different stimuli, with eosinophils being more responsive to protein kinase C activators and neutrophils to opsonised particles. They also show that histamine selectively induced the generation of superoxide anions by equine eosinophils via histamine-1 receptor activation. Thus, in horses with insect hypersensitivity, histamine released from cutaneous mast cells after antigen challenge could activate eosinophils which have migrated into the dermis.     

Prostanoid action on the human pulmonary vascular system

1. Four types of prostanoid receptor are present on pulmonary arterial vessels of man. Thromboxane (TP) receptors mediate constriction and are blocked by antagonists such as BAY u-3405, GR 32,191 and EP 169. Prostaglandin (PG) EP3 receptors also mediate constriction, the agonist potency ranking being SC 46,275 > sulprostone > misoprostol > or = PGE2; this action needs to be borne in mind when PGE analogues are used therapeutically. 2. Prostaglandin E2 causes relaxation in a few pulmonary artery preparations: an EP2 receptor may be involved. Prostacyclin, acting through i.p. receptors, consistently produces relaxation and studies are in progress to determine the contribution made by K(+)-channel opening. Agonist potencies of stable prostacyclin analogues and non-prostanoid prostacyclin mimetics, such as BMY 45,778 and the novel diphenylindole CU 23, on human pulmonary artery and platelets are well correlated. Interestingly, the non-prostanoid mimetics show persistent relaxant effects in vitro, which may be related to their high lipophilicities. 3. Prostacyclin and iloprost are being used to treat severe pulmonary hypertension; further study of the pharmacodynamic and pharmacokinetic properties of other i.p. receptor agonists could produce improved therapy.     

Adsorption of fibrinogen to droplets of liquid hydrophobic phases. Functionality of the bound protein and biological implications

Fibrinogen adsorbs spontaneously from aqueous media containing that protein to droplets of liquid hydrophobic phases dispersed in those same media. Examples of such phases include mineral oils, straight-chain hydrocarbons, and various plant- and animal-derived oils. Lecithin preexisting on the surface of oil droplets reduces significantly the amount of fibrinogen that can otherwise bind to them. When bound, fibrinogen remains active in the classic sense of fibrin gelation. As a consequence, oil droplets coated with fibrinogen can participate in a host of biologically important adhesive processes in which the protein would be expected to participate. Certain polyanions, eg, heparin, pentosan polysulfate, dextran sulfate, and suramin, bind to adsorbed fibrin(ogen) and prevent thrombin-dependent adhesion of fibrinogen-coated surfaces. Thus, these polyanions can be used to prevent adhesion between fibrin(ogen)-coated oil droplets and other fibrin(ogen)-coated surfaces. Potential practical applications and biological implications of these phenomena are presented and discussed.     

An unusual presynaptic action of Bothrops insularis snake venom mediated by phospholipase A2 fraction

A phospholipase A2-containing fraction was isolated from the venom of Bothrops insularis by a combination of gel filtration on Sephadex G-150 and ion exchange chromatography on DEAE-Sephadex. Peak IV of the latter chromatography containing all of the phospholipase A2 (PLA2) activity, was assayed on isolated neuromuscular preparations. In the mouse phrenic nerve-diaphragm incubated in Tyrode at 37 degrees C, the PLA2 fraction produced an initial increase in the twitch tension and in the frequency of the mepps, followed by a dose-dependent, irreversible blockade. The replacement of 1.8 mM Ca2+ by 4 mM Sr2 inhibited the neuromuscular blocking effect of the fraction. In the chick hiventer cervicis preparation incubated with Krebs solution at 37 degrees C, the PLA2 fraction induced blockade but did not affect the response to acetylcholine and K+, excluding the involvement of post-synaptic and direct muscular effects. A low temperature (18-22 degrees C) incubation prevented the neuromuscular effect from developing. These results suggest that the PLA2-containing fraction acts predominantly at presynaptic sites at the neuromuscular junction. This fraction also accounts for most of the pharmacological effects of the crude venom.     

Nonparametric estimation of covariance structure in longitudinal data

The three possible disulfide bonded isomers of alpha-conotoxin GI have been selectively synthesised and their structures determined by 1H NMR spectroscopy. alpha-Conotoxin GI derives from the venom of Conus geographus and is a useful neuropharmacological tool as it selectively binds to the nicotinic acetylcholine receptor (nAChR), a ligand-gated ion channel involved in nerve signal transmission. The peptide has the sequence ECCNPACGRHYSC-NH2, and the three disulfide bonded isomers are referred to as GI(2-7;3-13), GI(2-13;3-7) and GI(2-3;7-13). The NMR structure for the native isomer GI(2-7;3-13) is of excellent quality, with a backbone pairwise RMSD of 0.16 A for a family of 35 structures, and comprises primarily a distorted 310 helix between residues 5 to 11. The two non-native isomers exhibit multiple conformers in solution, with the major populated forms being different in structure both from each other and from the native form. Structure-activity relationships for the native GI(2-7;3-13) as well as the role of the disulfide bonds on folding and stability of the three isomers are examined. It is concluded that the disulfide bonds in alpha-conotoxin GI play a crucial part in determining both the structure and stability of the peptide. A trend for increased conformational heterogeneity was observed in the order of GI(2-7;3-13)相似文献   

Regulation and tissue distribution of the human sodium iodide symporter gene

The inclusion of an appropriate internal control DNA in polymerase chain reaction (PCR) is a rapid and simple method for the detection of PCR failure. Two PCR coamplification internal control DNAs (ICD I and ICD II) with the same primer-binding sequences as the target DNA for the detection of Bordetella pertussis and Bordetella parapertussis were produced using an overlap extension technique and a PCR MIMIC construction kit, respectively. The ICD II was further evaluated in a prospective clinical study in 360 patients with a clinical diagnosis of pertussis. From 360 nasopharyngeal swabs the internal control was positive in 318 (88%) samples, but was negative in 42 (12%). After phenol-chloroform extraction an additional 10 internal controls became positive. For the detection of PCR failure, the use of internal control DNA is highly recommended for PCR-based identification of B. pertussis and B. parapertussis organisms from nasopharyngeal swabs and aspirates.