Antibiotic effects on bacterial profile in osteonecrosis of the jaw

OBJECTIVE

Oral infection is considered to play a critical role in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ), and antibiotic therapy has become a mainstay of BRONJ therapy. This study was aimed to investigate the effect of antibiotics on bacterial diversity in BRONJ tissues.

MATERIALS AND METHODS

The bacterial profile from soft tissues associated with the BRONJ lesion was determined using 16S rRNA-based denaturing gradient gel electrophoresis (DGGE) and sequencing. Twenty BRONJ subjects classified as stage 0-2 were enrolled in this study, and patient groups were divided into an antibiotic cohort (n=10) treated with systemic antibiotic and a non-antibiotic cohort (n=10) with no prior antibiotic therapy.

RESULTS

The DGGE fingerprints indicated no significant differences in bacterial diversity of BRONJ tissue samples. Patients on antibiotics had higher relative abundance of phylum Firmicutes with bacterial species, Streptococcus intermedius, Lactobacillus gasseri, Mogibacterium timidum, and Solobacterium moorei, whereas patients without antibiotics had greater amounts of Parvimonas micra and Streptococcus anginosus. Thirty percent of bacterial populations were uncultured (yet-to be cultured) phylotypes.

CONCLUSION

This study using limited sample size indicated that oral antibiotic therapy may have a limited efficacy on the bacterial population associated with BRONJ lesions.

Degradation of surfactant wastewater under microwave irradiation in the presence of activated carbon assisted with nano-sized TiO2 or nano-sized ZnO

An improved method treating surfactant wastewater by the addition of semiconductor material such as nano-sized TiO2 or ZnO to activated carbon (AC) with microwave (MW) irradiation was proposed so as to assist efficient degradation of organic pollutants. A series of degradation experiments of sodium dodecyl benzene sulfonate (SDBS) were carried out under MW irradiation in the presence of AC/TiO2 or AC/ZnO. The influences of catalyst dose, irradiation time, initial SDBS concentration and solution acidity on the degradation were assessed in detail. The results showed that the addition of TiO2 or ZnO obviously promoted the degradation and AC/TiO2 system displayed higher catalytic activity under MW irradiation. Thus the method of MW irradiation with AC/TiO2 or AC/ZnO revealed many advantages of rapid degradation rate, short irradiation time, low cost, no residual intermediates and no secondary pollution in applications.

Outcome in acute stroke with different intra-arterial infusion rate of urokinase on thrombolysis

Intra-arterial infusion of urokinase (UK) has been widely used. However, the optimal infusion rate of the reagent has never been determined. This was investigated in the acute stage of middle cerebral artery (MCA) embolism in the present study. Sprague Dawley male rats (n=43) were randomly divided into sham-operation and five ischemic groups with urokinase administration at different infusion rates or without urokinase administration. Ischemia was induced with MCA embolism. Two hours after embolism, total urokinase (urokinase, 170,000U/kg) was given in groups A,B,C and D (n=8 each) at different rates: 1,000 U (0.03 ml/min) per minute, 4,000U (0.12 ml/min), 10,000U (0.30 ml/min), and 16,000U (0.48 ml/min), respectively. Group E received normal saline at a rate of 0.48 ml/min. The sham-operation group (no embolism) received urokinase at (170,000U/kg, 1.5 ml, 16,000 U/min). During ischemia and thrombolysis, regional cerebral blood flow (CBF) was monitored by laser Doppler flowmetry. The neurological deficits, infarct volumes and mortalities in each group were determined. The CBF in ischemic hemisphere were significantly (p<0.05) decreased after embolism in groups A∼E at similar levels (27.32±8.20% to 34.71±6.84%). After different treatments, in group B 4,000U/min infusion of UK induced the best reperfusion, the least neurological deficits and infarct volume, as well as the least mortality and lowest incidence of hemorrhage. The effect of intra-artery thrombolysis of urokinase was related to the infusion rate. Our study demonstrated an optimal infusion rate at 4,000U/min, suggesting relatively low levels of infusion are better able to improve brain reperfusion and reduce brain injury after stroke.

Antitumour response of a double mutant of staphylococcal enterotoxin C2 with the decreased affinity for MHC class II molecule

Staphylococcal enterotoxin C2 (SEC2) is one of the most potent known activators of human T lymphocytes, and recombinant SEC2 shows promising clinical values, but SEC2 can cause food poisoning and toxic shock syndrome in vivo. In this study, site-directed mutagenesis has been used to introduce alanine substitutions at Phe144 and Leu45 in the molecule. The mutant genes were cloned and expressed, and the corresponding proteins were purified by nickel agarose affinity chromatography. We found that the SEC2 mutant proteins could stimulate the proliferation of human peripheral blood lymphocytes and inhibit the growth of tumour cells as native SEC2. Furthermore, flow cytometry assay showed that mSEC2(F44A, L45A) drastically reduced the ability of the toxin to bind to MHC class II. Physiological parameters revealed that mSEC2(F44A, L45A) reduced significantly rat temperature compared with native SEC2 in vivo. Our results clearly suggest that this genetically modified SEC2 protein is less toxic and justifies its further development as a new, safer antitumour superantigen to prevent SEC2 intoxication.

Characterization of particles emitted by incense burning in an experimental house

The potential health effects of fine and ultrafine particles are of increasing concern. A better understanding of particle characteristics and dispersion behavior is needed. This study aims at characterizing spatial and temporal variations in fine and ultrafine particle dispersion after emission from a model source in an experimental house. Particles emitted by an incense stick burning for 15 min were characterized. Number concentration, specific surface area and mass were measured. Partial chemical analysis of particles was also realized. Near the burning incense stick, the maximum concentration was 25,500 particles/cm(3); the indoor PM(2.5) concentration reached 197 microg/m(3), and the specific surface area concentration was 180 microm(2)/cm(3). The estimated incense smoke density was 1.1 g/cm(3). Time of Flight Aerosol Mass Spectrometer measurements indicated that the organic fraction was predominant in the aerosol mass detected, and other minor components identified were K(+), NO(3)(-), and Cl(-). The combustion of an incense stick in the living room was associated with significant modifications of the concentrations of particles measured in the different rooms of the house. This demonstration of pollution by particle dispersion by a model source of moderate intensity may have significant implications in terms of assessment of indoor exposure to such particles. Practical Implications The particles emitted in a domestic environment by a source of moderate intensity such as burning incense disperse throughout the house, even in rooms with closed doors and in rooms as far away as the next floor. This dispersion has significant implications in terms of evaluating human indoor exposure to fine and ultrafine particles.

Exercise preconditioning reduces neuronal apoptosis in stroke by up-regulating heat shock protein-70 (heat shock protein-72) and extracellular-signal-regulated-kinase 1/2

Exercise preconditioning induces neuroprotection after stroke. We investigated the beneficial role of heat shock protein-70 (HSP-70) and phosphorylated extracellular-signal-regulated-kinase 1/2 (pERK 1/2), as they pertain to reducing apoptosis and their influence on Bcl-x(L), Bax, and apoptosis-inducing factor (AIF) in rats subjected to ischemia and reperfusion. Adult male Sprague-Dawley rats were subjected to 30 min of exercise on a treadmill for 1, 2, or 3 weeks. Stroke was induced by a 2-h middle cerebral artery (MCA) occlusion using an intraluminal filament. Protein levels of HSP-70, pERK 1/2, Bcl-x(L), Bax, and AIF were analyzed using Western blot. Neuroprotection was based on levels of apoptosis (TUNEL) and infarct volume (Nissl staining). Immunocytochemistry was used for cellular expression of HSP-70 and pERK 1/2. Significant (P<0.05) up-regulation of HSP-70 and pERK 1/2 after 3 weeks of exercise coincided with significant (P<0.05) reduction in neuronal apoptosis and brain infarct volume. Inhibition of either one of these two factors showed a significant (P<0.05) reversal in the neuroprotection. Bax and AIF were down-regulated, while levels of Bcl-x(L) were up-regulated in response to stroke after exercise. Inhibiting HSP-70 or pERK 1/2 reversed this resultant increase or decrease. Our results indicate that exercise diminishes neuronal injury in stroke by up-regulating HSP-70 and ERK 1/2.

1-Benzyl-3-methyl-imidazolium chloride 0.25-hydrate

The asymmetric unit of the title compound, C₁₁H₁₃N₂⁺·Cl⁻, contains two independent ion pairs and and half a solvent water mol­ecule (m site symmetry for the O atom). The imidazole ring is oriented at dihedral angles of 66.61 (3) and 89.17 (3)° with respect to the aromatic ring in the two cations. In the crystal, O—H⋯(O,Cl) hydrogen bonds and π–π stacking inter­actions between the imidazole ring of one mol­ecule and the aromatic ring of another [perpendicular distance = 3.4 (4) Å] link the mol­ecules.

Laminin enhances beta(2)-adrenergic receptor stimulation of L-type Ca(2+) current via cytosolic phospholipase A(2) signalling in cat atrial myocytes

We previously reported that attachment of atrial myocytes to the extracellular matrix protein laminin (LMN), decreases adenylate cyclase (AC)/cAMP and increases beta(2)-adrenergic receptor (AR) stimulation of L-type Ca(2+) current (I(Ca,L)). This study therefore sought to determine whether LMN enhances beta(2)-AR signalling via a cAMP-independent mechanism, i.e. cytosolic phospholipase A(2) (cPLA(2)) signalling. Studies were performed on acutely isolated atrial myocytes plated on uncoated coverslips (LMN) or coverslips coated with LMN (+LMN). As previously reported, 0.1 microm zinterol (zint-beta(2)-AR) stimulation of I(Ca,L) was larger in +LMN than LMN myocytes. In +LMN myocytes, zint-beta(2)-AR stimulation of I(Ca,L) was inhibited by inhibition of cPLA(2) by arachidonyltrifluoromethyl ketone (AACOCF(3); 10 microm), inhibition of G(i) by pertussis toxin and chelation of intracellular Ca(2+) by 10 microm BAPTA-AM. In contrast to zinterol, stimulation of I(Ca,L) by fenoterol (fen-beta(2)-AR), a beta(2)-AR agonist that acts exclusively via G(s) signalling, was smaller in +LMN than LMN myocytes. Arachidonic acid (AA; 5 microm) stimulated I(Ca,L) to a similar extent in LMN and +LMN myocytes. Inhibition of cAMP-dependent protein kinase A (cAMP/PKA) by either 5 mum H89 or 1 microm KT5720 in LMN myocytes mimicked the effects of +LMN myocytes to enhance zint-beta(2)-AR stimulation of I(Ca,L), which was blocked by 10 microm AACOCF(3). In contrast, H89 inhibited fen-beta(2)-AR stimulation of I(Ca,L), which was unchanged by AACOCF(3). Inhibition of ERK1/2 by 1 microm U0126 inhibited zint-beta(2)-AR stimulation of I(Ca,L) in +LMN myocytes and LMN myocytes in which cAMP/PKA was inhibited by KT5720. In LMN myocytes, cytochalasin D prevented inhibition of cAMP/PKA from enhancing zint-beta(2)-AR stimulation of I(Ca,L). We conclude that LMN enhances zint-beta(2)-AR stimulation of I(Ca,L) via G(i)/ERK1/2/cPLA(2)/AA signalling which is activated by concomitant inhibition of cAMP/PKA signalling and dependent on the actin cytoskeleton. These findings provide new insight into the cellular mechanisms by which the extracellular matrix can remodel beta(2)-AR signalling in atrial muscle.

Intra-arterial thrombolysis for acute central retinal artery occlusion

OBJECTIVE

In this study, we aimed at exploring the effect and safety of local intra-arterial thrombolysis on acute central retinal artery occlusion.

METHODS

Retrospective data analysis of 49 consecutive acute central retinal occlusion patients was performed. All the patients were treated with urokinase perfusion through the ophthalmology artery within the first 6 hours after central retinal artery occlusion attack. Conventional treatments including intra-ocular pressure decreasing, microcirculation improvement, neuroprotection and antiplatelet aggregation were conducted. The visual acuity (with International Snellen Chart) and field of vision were detected after thrombolysis. The complications and adverse events were observed.

RESULTS

Recanalization was found in 71% of patients. The visual acuity improvement was greater in the recanalization group (n=35) than in the non-recanalization group (n=14). The averaged visual acuity was 0.15+/-0.02, 0.25+/-0.03 and 0.4+/-0.05 after 2, 28 days and 6 months, respectively. Of the patients, 24.5% regained >0.6 of visual acuity, and the visual field deficit was less than 30% in 34.7% of patients after 28 days. Six months later, 36.7% patients regained visual acuity of >0.6, and the field deficit was less than 30% in 44.9% of patients. The difference between visual acuity in recanalization (0.6+/-0.04) and non-recanalization (0.002+/-0.0012) patients after 6 months after thrombolysis was significant (p>0.05).

CONCLUSIONS

Intra-arterial thrombolysis could obviously improve the short- and long-term visual function for patients with acute central retinal artery occlusion within 6 hours of symptom onset.

Recombinant Human Erythropoietin Protects against Experimental Spinal Cord Trauma Injury by Regulating Expression of the Proteins MKP-1 and p-ERK

The present study explored the tissue-protective effect of erythropoietin in rats after experimental spinal cord injury (SCI) produced by dropping a weight onto surgically exposed spinal cord. Sixty rats were randomized to sham operation (spinal cord exposure; control), SCI plus intraperitoneal saline injection, or SCI plus intraperitoneal erythropoietin injection. Locomotor function was evaluated with Basso, Beattie and Bresnahan scores 1 day (24 h) and 7 days later, and rats were then killed for analysis of lesion site tissue. Compared with saline-treated SCI rats, erythropoietin-treated SCI rats showed significantly less locomotor dysfunction and faster locomotor recovery. Immunohistochemistry showed that erythropoietin-treated SCI rats had a significantly lower phospho-extracellular signal-regulated kinase (p-ERK) protein expression and a significantly higher mitogen-activated protein kinase phosphatase-1 (MKP-1) protein expression than saline-treated SCI rats. Haematoxylin–eosin staining showed progressive disruption of dorsal white matter and neuron loss after SCI; lesions were less severe and there was more neuron regeneration in the erythropoietin group than in the saline group. It is concluded that erythropoietin reduces pathological changes and SCI severity via down-regulation of p-ERK and up-regulation of MKP-1.

Laminin acts via focal adhesion kinase/phosphatidylinositol-3' kinase/protein kinase B to down-regulate beta1-adrenergic receptor signalling in cat atrial myocytes

We previously reported that short-term (2 h) plating of cat atrial myocytes on the extracellular matrix protein, laminin (LMN) decreases adenylate cyclase activity and beta(1)-adrenergic receptor (beta(1)-AR) stimulation of L-type Ca(2+) current (I(Ca,L)). The present study sought to determine whether LMN-mediated down-regulation of beta(1) signalling is due to down-regulation of adenylate cyclase and to gain insight into the signalling mechanisms responsible. beta(1)-AR stimulation was achieved by 0.01 microm isoproterenol (isoprenaline) plus 0.1 microm ICI 118551, a selective beta(2)-AR antagonist. Atrial myocytes were plated for at least 2 h on uncoated cover-slips (-LMN) or cover-slips coated with LMN (+LMN). As previously reported, beta(1)-AR stimulation of I(Ca,L) was significantly smaller in +LMN compared to -LMN atrial myocytes. In -LMN myocytes, 10 microm LY294002 (LY), a specific inhibitor of PI-(3)K, had no effect on beta(1)-AR stimulation of I(Ca,L). In +LMN myocytes, however, LY significantly increased beta(1)-AR stimulation of I(Ca,L). Western blots revealed that compared with -LMN myocytes, +LMN myocytes showed a significant increase in Akt phosphorylation at Ser-473, which was prevented by LY. In another approach, +LMN myocytes were infected (multiplicity of infection (MOI), 100; 24 h) with replication-defective adenoviruses (Adv) expressing dominant-negative inhibitors of focal adhesion kinase (FAK) (Adv-FRNK or Adv-Y397F-FAK) or Akt (Adv-dnAkt). Compared with control cells infected with Adv-beta-galactosidase, cells infected with Adv-FRNK, Adv-Y397F-FAK or Adv-dnAkt each exhibited a significantly greater beta(1)-AR stimulation of I(Ca,L). In -LMN myocytes LY had no effect on forskolin (FSK)-stimulated I(Ca,L). However, in +LMN myocytes LY significantly increased FSK-stimulated I(Ca,L). Similar results were obtained in +LMN atrial myocytes infected with Adv-FRNK. We conclude that LMN binding to beta(1)-integrin receptors acts via FAK/PI-(3)K/Akt to inhibit adenylate cyclase activity and thereby down-regulates beta(1)-AR-mediated stimulation of I(Ca,L). These findings provide new insight into the cellular mechanisms by which the extracellular matrix can modulate atrial beta-AR signalling.

2-Nitro-p-phenyl-ene bis-(toluene-sulfonate)

In the mol­ecule of the title compound, C₂₀H₁₇NO₈S₂, the two toluene rings are oriented at a dihedral angle of 3.65 (4)°, while the nitrophenyl ring is oriented at dihedral angles of 44.39 (3) and 47.44 (3)° with respect to the toluene rings. An intra­molecular C—H⋯O hydrogen bond results in the formation of a five-membered ring, which adopts an envelope conformation. In the crystal structure, inter­molecular C—H⋯O hydrogen bonds link the mol­ecules. There is a π–π contact between the toluene rings [centroid–centroid distance = 4.035 (1) Å].

Ginsenoside Re suppresses electromechanical alternans in cat and human cardiomyocytes

Ginseng botanicals are increasingly used as complementary or alternative medicines for a variety of cardiovascular diseases, yet little is known about their cellular actions in cardiac muscle. Electromechanical alternans (EMA) is a proarrhythmic cardiac abnormality that results from disturbances of intracellular Ca(2+) homeostasis. This study sought to determine whether a purified ginsenoside extract of ginseng, Re, exerts effects to suppress EMA and to gain insight into its mechanism of action. Alternans was induced by electrically pacing cardiomyocytes at room temperature. Re (> or = 10 nM) reversibly suppressed EMA recorded from cat ventricular and atrial myocytes and Langendorff-perfused cat hearts. In cat ventricular myocytes, Re reversibly suppressed intracellular Ca(2+) concentration ([Ca(2+)](i)) transient alternans. Re exerted no significant effects on baseline action potential configuration or sarcolemmal L-type Ca(2+) current (I(Ca,L)), Na(+) current, or total K(+) conductance. In human atrial myocytes, Re suppressed mechanical alternans and exerted no effect on I(Ca,L). In cat ventricular myocytes, Re increased [Ca(2+)](i) transient amplitude and decreased sarcoplasmic reticulum (SR) Ca(2+) content, resulting in an increase in fractional SR Ca(2+) release. In SR microsomes isolated from cat ventricles, Re had no effect on SR Ca(2+) uptake. Re increased the open probability of ryanodine receptors (RyRs), i.e., SR Ca(2+)-release channels, isolated from cat ventricles and incorporated into planar lipid bilayers. We concluded that ginsenoside Re suppresses EMA in cat atrial and ventricular myocytes, cat ventricular muscle, and human atrial myocytes. The effects of Re are not mediated via actions on sarcolemmal ion channels or action potential configuration. Re acts via a subcellular mechanism to enhance the opening of RyRs and thereby overcome the impaired SR Ca(2+) release underlying EMA.