Traumatic intercostal artery pseudoaneurysm following a bicycle accident.

In this article we present a fatal case of a ruptured intercostal artery pseudoaneurysm that occurred a number of years after an incident in which the patient suffered a blunt-trauma injury. A long interval between blunt trauma and this type of fatality has rarely been reported. This case discusses a 49-year-old woman who was found dead at her home by her husband and was referred for autopsy because the cause of death was uncertain. Her past medical history was unknown; however, it was learned that she had a bicycle accident 4 years previously and had sustained injuries to the left side of her body. During the autopsy, healed fractures in the bones of the left lower rib cage and a large amount of blood in the left thorax were observed. Furthermore, a hematoma, containing a small rupture was found in the left tenth intercostal space adjacent to the thoracic vertebrae. Histological examinations showed that the wall of the left tenth intercostal artery was ruptured, with recent blood clots including fibrin. Additionally, in the lesion where the tunica adventitia was disrupted, the dissecting cavity was filled with blood. We concluded that the woman died of hemorrhagic shock resulting from a ruptured intercostal artery pseudoaneurysm that formed as a result of the injury incurred from the bicycle accident 4 years before.

Evidence for involvement of p59fyn in fasting-induced thymic involution.

p59fyn, a member of the src-family protein tyrosine kinase, is expressed abundantly in thymus. We examined the possible involvement of p59fyn in thymic involution induced by a fasting stress in Fyn-/- mice. An acute 48 h fast resulted in severe atrophy of the thymus and a marked decrease of the total thymocyte number with depletion of the CD4+CD8+[double positive (DP)] population in Fyn+/+ (control) mice. A remarkable increase in terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling-positive signals was detected in the fasted group of control mice. However, these findings were not observed in Fyn-/- mice. Interestingly, MRL/MPJ-lpr/lpr, a Fas-deficient model animal, also showed no significant decrease of DP cell numbers in the fasted group. p59fyn is known to interact with Fas signalling, and these findings suggest that p59fyn is involved in fasting-induced thymic involution, raising the possibility that Fas/p59fyn-mediated signalling may, at least partially, be associated with the phenomenon.

Immobilization stress-induced thymocyte apoptosis in rats.

Immobilization of rats is a well known model of emotional stress. We studied apoptosis in rat thymocytes during immobilization for 2-8 hours (h). Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells increased with time of immobilization. The positive cells increased significantly after 2 h and comprised about 33% of total cells after 8 h. The apoptotic cells aggregated as scattered foci predominantly in the cortex of the thymus and diffusely distributed with time of the stress. The DNA laddering also increased with time of immobilization, which was inhibited by a glucocorticoid receptor antagonist, RU-486. These results suggest that the emotional stress evoked by immobilization induces thymocyte apoptosis through glucocorticoid overflow.

Development of rigor mortis is not affected by muscle volume.

There is a hypothesis suggesting that rigor mortis progresses more rapidly in small muscles than in large muscles. We measured rigor mortis as tension determined isometrically in rat musculus erector spinae that had been cut into muscle bundles of various volumes. The muscle volume did not influence either the progress or the resolution of rigor mortis, which contradicts the hypothesis. Differences in pre-rigor load on the muscles influenced the onset and resolution of rigor mortis in a few pairs of samples, but did not influence the time taken for rigor mortis to reach its full extent after death. Moreover, the progress of rigor mortis in this muscle was biphasic; this may reflect the early rigor of red muscle fibres and the late rigor of white muscle fibres.

Imidazoline Receptor Contributes to Ion and Water Transport across the Intestine of the Eel Acclimated to Sea Water.

Guanabenz, an I2-imidazoline-related compound with high affinity for intestinal membrane of the eel (), enhanced the transepithelial potential difference (PD) and short-circuit current (Isc) from serosa to mucosa after pretreatment with isobutylmethylxanthine (IBMX), serotonin (5-HT) and methacholine (MCh). The mucosal effect of guanabenz was not mimicked by adrenaline, indicating that the mucosal guanabenz binding site is not adrenoceptors. The mucosal guanabenz enhanced the Isc in a concentration-dependent manner. Similar enhancement in the Isc was also obtained after addition of other imidazoline derivatives such as ST93, clonidine, ST91, naphazoline and UK14,304 into the mucosal fluid. On the other hand, the effect of guanabenz was completely blocked by mucosal RX821002 or efaroxan, another imidazoline derivatives. Since some imidazoline derivatives act as agonists and others as antagonist, there must exist imidazoline receptor on the mucosal side of the eel intestine. Accompanied by an increase in the PD, NaCl and water absorption across the intestine was also enhanced by mucosal guanabenz. To search for endogenous ligands for the imidazoline receptor, luminal fluid in the intestine of the seawater eels was collected. However, most luminal fluid was ineffective. Only one among 10 samples showed guanabenz-like activity, suggesting that the endogenous ligands is secreted into the lumen under restricted condition alone.

A study of the ditiophosphoric acid diacylester as a masking agent for the determination of bismuth in the presence of copper by hydride generation atomic absorption spectrometry.

The masking action of the dithiophosphoric acid diacylester (DDTP) for the determination of Bi by hydride generation absorption spectrometry (HGAAS) in the presence of high concentrations of copper was studied. Cu/Bi ratios up to 50x10(3) were found to be tolerable in the presence of 2x10(-3) M chelating solutions in 10% HCl, using 1.5% NaBH(4) as reductant. Good agreement between the certified values and those found in the present study was verified in the analysis of certified reference materials.

Coupling of the expressed cannabinoid CB1 and CB2 receptors to phospholipase C and G protein-coupled inwardly rectifying K+ channels.

Signaling of the cannabinoid CB1 and CB2 receptors through phospholipase C (PLC) and G protein-coupled inwardly rectifying K+ channels (GIRK) was studied after their expression in COS7 cells and Xenopus oocytes. The CB1 or CB2 receptor was co-expressed with alpha subunits of the Galphaq family (Galphaq, Galpha11, Galpha14, Galpha15 and Galpha16) in COS7 cells. Receptor-dependent activation of PLC was observed after co-expressing the CB1 receptor with Galpha14, Galpha15 or Galpha16 but not with Galphaq or Galpha11. Co-expression of Gbeta1 and Ggamma2 abolished the activation, indicating that the activation was mediated by Galpha. PLC activation was not observed when the CB2 receptor was expressed alone or co-expressed with any of the above Galpha subunits. Coupling to GIRK was observed with both CB1 and CB2 receptors after expression in Xenopus oocytes. Significantly larger currents were induced when the receptor was co-expressed with both GIRK1 and GIRK4 than with either GIRK alone. Co-expression of Galpha transducin with the receptor significantly reduced the K+ currents, indicating that GIRK activation was mediated by Gbetagamma but not by Galpha. These findings suggest two new signaling pathways for the cannabinoid receptors.

Inhibition of the growth of cariogenic bacteria in vitro by plant flavanones.

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified from Sophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 micrograms/ml.

Comparative study of the cellular fatty acids of methicillin-resistant and -susceptible Staphylococcus aureus.

The cellular fatty acid compositions of 26 strains of methicillin-resistant Staphylococcus aureus (MRSA) and 17 strains of methicillin-susceptible S. aureus (MSSA) were analyzed by gas-liquid chromatography. The fatty acid compositions of the two groups were very similar with 16 identified components. The major fatty acids were Ci14 = 0, Ci15 = 0, C18 = 0 and C20 = 0. Among these fatty acids, the percentage of the Ci15 = 0 fatty acid component of MRSA strains (11.4 +/- 3.9%) was statistically higher than that of MSSA strains (6.2 +/- 2.4%) (p < 0.001). On the other hand, the percentage of the C20 = 0 fatty acid components of MRSA strains (20.2 +/- 8.8%) was statistically lower than that of MSSA strains (30.7 +/- 10.4%) (p < 0.001). The production of beta-lactamase and beta-hemolysin in both groups' strain was also unrelated to the relative amounts of the fatty acid components. These results indicated a statistical tendency for the percentage fatty acid compositions of the MRSA strains to be quantitatively different from those of the MSSA for both the Ci15 = 0 and C20 = 0 fatty acid components. Analysis of the fatty acid compositions may have an application in the differentiation of MRSA and MSSA strains.

Cathodic adsorptive stripping voltammetry of nickel complexed with hydroxynaphthol blue at a static mercury drop electrode.

A new method is described for the determination of Ni based on the cathodic adsorptive stripping of Ni(II) complexed with hydroxynaphthol blue (HNB) at a static mercury drop electrode. Optimal conditions were found to be: accumulation potential -0.50 V (vs. Ag/AgCl); final potential -1.10 V; accumulation time 50 sec; scan rate 200 mV/sec; linear scan mode; filter 0.1 sec; supporting electrolyte acetic acid/acetate (0.25M, pH = 6.0) and concentration of HNB 3.3 x 10(-5)M. The response of the system was found to be linear in a range of Ni concentrations from 25 ppb to the detection limit. The detection limit was found to be 1.7 nM (0.10 ppb) with 2 mins of accumulation time. The effect of various potential interferences (including a variety of cations, anions and organic surfactants) were also studied. With the exception of Co, at less than equimolar concentrations no significant interferences were observed. Al was found to interfere at high concentrations with respect to Ni, but Al concentrations up to 1000 ppb may be masked by sodium citrate or sodium fluoride. The utility of the method is demonstrated by the recovery of Ni in a doped sample of commercial mineral water.

Genes encoding two lipoproteins in the leuS-dacA region of the Escherichia coli chromosome.

The coding of two rare lipoproteins by two genes, rlpA and rlpB, located in the leuS-dacA region (15 min) on the Escherichia coli chromosome was demonstrated by expression of subcloned genes in a maxicell system. The formation of these two proteins was inhibited by globomycin, which is an inhibitor of the signal peptidase for the known lipoproteins of E. coli. In each case, this inhibition was accompanied by formation of a new protein, which showed a slightly lower mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and which we suppose to be a prolipoprotein with an N-terminal signal peptide sequence similar to those of the bacterial major lipoproteins and lysis proteins of some bacteriocins. The incorporation of 3H-labeled palmitate and glycerol into the two lipoproteins was also observed. Sequencing of DNA showed that the two lipoprotein genes contained sequences that could code for signal peptide sequences of 17 amino acids (rlpA lipoprotein) and 18 amino acids (rlpB lipoprotein). The deduced sequences of the mature peptides consisted of 345 amino acids (Mr 35,614, rlpA lipoprotein) and 175 amino acids (Mr 19,445, rlpB lipoprotein), with an N-terminal cysteine to which thioglyceride and N-fatty acyl residues may be attached. These two lipoproteins may be important in duplication of the cells.

Peptidoglycan synthetic activities in membranes of Escherichia coli caused by overproduction of penicillin-binding protein 2 and rodA protein.

Penicillin-binding protein (PBP)-2 and the RodA protein are known to function in determining the rod shape of Escherichia coli cells. Peptidoglycan biosynthetic reactions that required these two proteins were demonstrated in the membrane fraction prepared from an E. coli strain that overproduced both of these two proteins and which lacked PBP-1B activity (the major peptidoglycan synthetase activity in the normal E. coli membranes). The cross-linked peptidoglycan was synthesized from UDP-N-acetylmuramylpentapeptide and UDP-N-acetylglucosamine in the presence of a high concentration of cefmetazole that inhibited all of PBPs except PBP-2. The peptidoglycan was synthesized via a lipid intermediate and showed up to 30% cross-linking. The cross-linking reaction was strongly inhibited by the amidinopenicillin, mecillinam, and by other beta-lactam antibiotics that have a high affinity for PBP-2, but not by beta-lactams that had very low affinity for PBP-2. The formation of peptidoglycan required the presence of high levels of both PBP-2 and the RodA protein in the membranes, but it is unclear which of the two proteins was primarily responsible for the extension of the glycan chains (transglycosylation). However, the sensitivity of the cross-linking reaction to specific beta-lactam antibiotics strongly suggested that it was catalyzed by PBP-2. The transglycosylase activity of the membranes was sensitive to enramycin and vancomycin and was unusual in being stimulated greatly by a high concentration of a chelating agent.

A multichemical defense mechanism of bitter oliveOlea europaea (oleaceae) : Is oleuropein a phytoalexin precursor?

Olea europaea (Oleaceae) is resistant in nature to insect and microbe attack. Two types of chemical protection were found in the foliage. One type is the bitterseco-iridoid glycosides oleuropein (1) and ligstroside (2); The other is a physical barrier of crystalline oleanolic acid (4) that coats the leaf surface. Theseco-iridoid glycosides were isolated using two different countercurrent chromatographies: rotation locular countercurrent chromatography (RLCC) and droplet countercurrent chromatography (DCCC). The dimethyl ester (III) was shown to be an artifact. This is the first isolation of ligstroside fromO. europaea. In an antimicrobial test by the paper disk method againstBacillus subtilis, Saccharomyces cerevisiae, andEscherichia coli, compounds I, II, and III inhibited a growth ofB. subtilis at pH 7. Similar tests under the influence of ß-glucosidase suggest an aglycone of oleuropein, either the hemiacetal (i) or the possible enal-aldehyde (ii), could be the active intermediate. This intermediate could be produced rapidly in response to microorganism invasion. Oleuropein producing such a postinfection active intermediate could be referred to as a phytoalexin precursor.