P. gingivalis and E. coli lipopolysaccharides exhibit different systemic but similar local induction of inflammatory markers

BACKGROUND: Porphyromonas gingivalis is a Gram-negative bacterium that is an important etiologic agent of human adult periodontitis. The goal of the study was to test the hypothesis that two isoforms of P. gingivalis lipopolysaccharide (PgLPS), PgLPS(1435)(/1449) and PgLPS(1690), exhibit differences in their capacity to stimulate systemic versus local responses compared to Escherichia coli lipopolysaccharide (LPS). METHODS: LPS was inoculated into the scalp of mice, and the response was measured locally at the site of inoculation and systemically in the heart/aorta. Vascular cell adhesion molecule (VCAM)-1 was assessed at the protein level by enzyme-linked immunosorbent assay, and VCAM-1, E-selectin, and intercellular adhesion molecule (ICAM)-1 were assessed at the RNA level of the RNase protection assay. Serum tumor necrosis factor-alpha (TNF-alpha) levels were also measured. RESULTS: E. coli LPS and both isoforms of P. gingivalis LPS were relatively potent in stimulating the expression of inflammatory markers, with E. coli LPS being more potent. In contrast, when the systemic response was measured in the heart/aorta, E. coli LPS, but not P. gingivalis LPS, significantly induced inflammatory markers. At moderate to low doses (1 and 10 microg per injection), serum TNF-alpha levels were minimally induced by P. gingivalis LPS compared to E. coli LPS. CONCLUSIONS: Both forms of P. gingivalis LPS stimulated an inflammatory response when injected into connective tissue but were minimally stimulatory when a systemic response was measured. In contrast, E. coli LPS was a potent stimulus at the systemic and local levels.     

Dacryoscintigraphy for the detection of ocular drainage system stenosis induced by docetaxel and fluorouracil

Docetaxel (D) is an antineoplastic agent of the taxane group produced by fir needles and is used in the treatment of breast, lung, prostate, stomach as well as of head and neck cancers. It is usually administered in weekly or 3-weekly regimens. Some side-effects of D are neutropenic fever, anemia, fluid retention, hypersensitivity reactions, anorexia, myalgias, mucositis, mild alopecia, skin and nail toxicity, peripheral neuropathy, canalicular stenosis and/or obstruction, epiphora and tearing. Extensive fibrotic changes in the stroma of the lacrimal sac and the nasal mucosa are the prominent histologic features of the canalicular narrowing and nasolacrimal duct obstruction. Furthermore, studies in patients receiving D treatment showed that after intravenous infusion, D was usually secreted in tears causing ocular irritation. The histologic evidence of keratinization with marked epidermalization of the surface epithelium, thickening, and parakeratosis of the squamous epithelium, confirms fibrosis. Epiphora is a greek word meaning that the line of tears (phora) runs over the eye (epi). Epiphora is a clinical sign or condition, in which tears drain down the face rather than through the nasolacrimal system. Epiphora may also be due to ocular irritation and inflammation or to obstruction of tear outflow tract, ie. ectropion, punctal, canalicular or nasolacrimal obstruction. For punctal stenosis punctoplasty is performed, for subtotal stenosis a permanent silicone tube is advocated and for total stenosis a permanent bypass is required. Dacryoscintigraphy is a well established diagnostic tool for the eye drainage apparatus, and its importance in diagnosing functional lacrimal duct obstruction and even classifying the types of obstruction to predict postoperative results of silicone tube insertion has been reported by others. Chemotherapeutic drugs like D tend to be especially toxic to normal tissues and usually interfere with cell growth or proliferation. Thus, excessive tear production and epiphora, occur as a side effect of D, as the afflicted fibrosis disrupts the continuation of the membranous channel. Although the severity and frequency of epiphora is less with the 3-weekly dosing schedule of D, an incidence of almost 40% has been reported even for this schedule, especially during the longer treatment regimes for metastatic breast cancer. We report on two patients with epiphora and canalicular stenosis developed while on a 3-weekly D treatment regime. Both our patients agreed to be monitored with dacryoscintigraphy. The patients were seated in front of the low energy high resolution (LEHR) collimator of the gamma camera, and after applying 0.1mL of (99m)Tc-pertechnetate of 3.7 MBq on the conjunctiva near the internal canthus of each eyeball we recorded bilateral eyeball images. A dynamic scintigraphy of the area was obtained (9 frames of 1min duration each, followed by one 5min frame, matrix 64x64, LEHR collimator and no zoom), as the (99m)Tc-pertechnetate flows along the tear strips, through the nasolacrimal drainage system, into the nasal fossa. By using LEHR collimator, the canaliculi, the lacrimal sac, the nasolacrimal duct and the Hasner's valve area are normally visualized. When the flow in the lacrimal apparatus is impaired, dacryoscintigraphy will demonstrate the blockage and may also identify the site of obstruction. A follow-up with a second dacryoscintigraphy, a month after the end of D treatment, was performed. The first patient, a 59 years old woman was treated for metastatic breast cancer with D. She received a 3-weekly treatment regime of 75mg/m2 (130 mg in total) intravenously, with dexamethasone coverage for a total of 6 cycles. She reported extensive tearing 2 weeks after the second cycle, which did not improve after discontinuation of the drug. She was advised to use artificial tears and visit the ophthalmology clinic. She had been reluctant to undergo any procedures but at least she agreed to be monitored with dacryoscintigraphy. Initial imaging of the drainage apparatus by dacryoscintigraphy, when symptoms appeared, showed complete bilateral blockage at the lower canaliculus. The second patient, a 54 years old male with metastatic gastric carcinoma received a combination of docetaxel 75 mg/m2 (120mg in total), carboplatin 450mg and 6 pills capecitabine (xeloda) of 500mg each, in a weekly treatment regime (3 weeks treatment and one week intermission), with dexamethasone coverage for a total of 6 cycles. This patient had also refused to visit an ophthalmology clinic but followed our instructions to use artificial tears. The first dacryoscintigraphy was performed as soon as epiphora appeared, a few days after the first cycle of D treatment and the second, a month after the end of 6 cycles of D treatment. Both dacryoscintigraphies, showed a bilateral total blockage of the drainage apparatus in the area of the lower canaliculus. Despite his complaints and discomfort, this patient was also reluctant to undergo any other procedures. Capecitabine is a prodrug converted into fluorouracil (5FU) in the tissues. This combination may increase the possibility of dacryostenosis. The cytotoxic metabolites of 5FU interfere with DNA replication and RNA synthesis in rapidly proliferating tear duct cells and may occasionally cause canalicular stenosis with intractable epiphora and even fibrosis, which is difficult to manage. Furthermore, 5FU is also known to cause mucosal inflammation, conjunctivitis and GI tract inflammations. It may also be hypersecreted from the lacrimal gland, thus tears gaining access over the ocular surface may cause ocular surface toxicity and reflex tearing. The development of cicatricial ectropion further exacerbates the situation. The possibility that the above stenoses could be partly due to viral infection in an immunocompromised patient cannot be excluded. The incidence and severity of lacrimation correlates with the concentration of 5FU in tears but is not directly related to its plasma levels. Epiphora can have a negative impact on the quality of life, because it induces inability to read, drive, put on make up and gives the false impression of emotional tearing. If left untreated, epiphora may have a negative impact on visual function, with significantly lower visual acuity scores. Artificial tears and/or eye drops containing corticosteroids are suggested for treatment. Patients receiving D and/or 5FU should be closely followed by an ophthalmologist for an early diagnosis and treatment of epiphora that may prevent closure of ocular canaliculi. Nuclear dacryoscintigraphy is simple, fast, cheap, and harmless technique for this diagnosis and may replace a more uncomfortable and not so specific technique like the Schirmer's test, in which a filter paper is placed in the lower lid of the eye and the amount of tears is measured. It would be valuable to add the importance of dacryoscintigraphy in the differential diagnosis of pseudoepiphora, which encompasses reflex tearing caused by inflammation or dry eyes, nasal disease, like allergic rhinitis, polyps, tumors or rhinoplasty. It has been suggested that dacryoscintigraphy is the best method for measuring the dynamics of tear drainage especially in the canaliculi, although some prefer the CT dacryocystography, which gives a much higher radiation dose to the patient. In conclusion, we have described one patient with epiphora after docetaxel treatment and another after both docetaxel and 5FU treatment and emphasize the diagnostic value of dacryoscintigraphy.     

Preliminary noise reduction efforts in a medical intensive care unit

Noise is a significant contributor to sleep disruption in the intensive care unit (ICU) that may result in increased patient morbidity such as delirium and prolonged length of stay in ICU. We conducted a pre-post intervention study in a 24-bed tertiary care academic medical ICU to reduce the mean noise levels. Baseline dosimeter recordings of ICU noise levels demonstrated a mean noise level of 54.2 A-weighted decibels (dBA) and peak noise levels of 109.9 dBA, well above the Environmental Protection Agency’s recommended levels. There were 1735 episodes of “defects” (maximum noise levels > 60 dBA). Following implementation of multipronged interventions, although the mean noise levels did not change significantly between pre- and post-intervention (54.2 vs 53.8 dBA; p = 0.96), there was a significant reduction in the number of “defects” post-intervention (1735 vs 1289, p ≤ 0.000), and the providers felt that the patients were sleeping longer in the ICU post-intervention.     

Native valve right sided infective endocarditis

Right-sided infective endocarditis (RSIE) accounts for 5–10% of all cases of infective endocarditis (IE), and is predominantly encountered in the injecting drug user (IDU) population, where HIV and HCV coinfections often coexist. Staphylococcus aureus is the most common pathogen. The pathogenesis of RSIE is still not well understood. RSIE usually presents as a persistent fever with respiratory symptoms whilst signs of systemic embolisation as seen in left-sided IE are notably absent. The prompt diagnosis of RSIE thus requires a high index of suspicion. Transthoracic echocardiography (TTE) can detect the majority of RSIE, whilst transoesophageal echocardiography (TOE) can increase sensitivity. Virulence of the causative organism and vegetation size are the major determinants of prognosis. Most cases of RSIE resolve with appropriate antibiotic administration.     

Validated LC–MS/MS method for simultaneous determination of SIM and its acid form in human plasma and cell lysate: Pharmacokinetic application

Simvastatin (SIM) is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor widely used in hyperlipidemia therapy. SIM has recently been studied for its anticancer activity at doses higher than those used for the hyperlipidemia therapy. This prompted us to study the pharmacokinetics of high-dose SIM in cancer patients. For this purpose, an LC–MS/MS method was developed to measure SIM and its acid form (SIMA) in plasma and peripheral blood mononuclear cells (PBMCs) obtained from patients. Chromatographic analyte separation was carried out on a reverse-phase column using 75:25 (% v/v) acetonitrile:ammonium acetate (0.1 M, pH 5.0) mobile phase. Detection was performed on a triple quadrupole mass spectrometer, equipped with a turbo ion spray source and operated in positive ionization mode. The assay was linear over a range 2.5–500 ng/mL for SIM and 5–500 ng/mL for SIMA in plasma and 2.5–250 ng/mL for SIM and 5–250 ng/mL for SIMA in cell lysate. Recovery was >58% for SIM and >75% for SIMA in both plasma and cell lysate. SIM and SIMA were stable in plasma, cell lysate and the reconstitution solution. This method was successfully applied for the determination of SIM and SIMA in plasma and PBMCs samples collected in the pharmacokinetic study of high-dose SIM in cancer patients.     

Mitochondrial ribonuclease P structure provides insight into the evolution of catalytic strategies for precursor-tRNA 5′ processing

Ribonuclease P (RNase P) catalyzes the maturation of the 5′ end of tRNA precursors. Typically these enzymes are ribonucleoproteins with a conserved RNA component responsible for catalysis. However, protein-only RNase P (PRORP) enzymes process precursor tRNAs in human mitochondria and in all tRNA-using compartments of Arabidopsis thaliana. PRORP enzymes are nuclear encoded and conserved among many eukaryotes, having evolved recently as yeast mitochondrial genomes encode an RNase P RNA. Here we report the crystal structure of PRORP1 from A. thaliana at 1.75 Å resolution, revealing a prototypical metallonuclease domain tethered to a pentatricopeptide repeat (PPR) domain by a structural zinc-binding domain. The metallonuclease domain is a unique high-resolution structure of a Nedd4-BP1, YacP Nucleases (NYN) domain that is a member of the PIN domain-like fold superfamily, including the FLAP nuclease family. The structural similarity between PRORP1 and the FLAP nuclease family suggests that they evolved from a common ancestor. Biochemical data reveal that conserved aspartate residues in PRORP1 are important for catalytic activity and metal binding and that the PPR domain also enhances activity, likely through an interaction with pre-tRNA. These results provide a foundation for understanding tRNA maturation in organelles. Furthermore, these studies allow for a molecular-level comparison of the catalytic strategies used by the only known naturally evolved protein and RNA-based catalysts that perform the same biological function, pre-tRNA maturation, thereby providing insight into the differences between the prebiotic RNA world and the present protein-dominated world.     

Ipsilateral and contralateral effects of proprioceptive neuromuscular facilitation techniques on hip motion and electromyographic activity.

The effects of two proprioceptive neuromuscular facilitation techniques on increasing the range of hip flexion during active straight leg raising were compared in 30 normal women. Subjects were randomly assigned into contract-relax, hold-relax, or control groups and were tested with the pelvis stabilized. An exercise technique was applied to the right lower extremity in two diagonal patterns while electrical activity was monitored from the contralateral rectus femoris, vastus medialis, semimembranosus, and biceps femoris muscles. Comparison of pretest and posttest measurements of the angle of straight leg raising of both lower extremities indicated that the increase in range of motion of the right lower extremity in subjects in the contract-relax group was significantly greater than that in the hold-relax and control groups. For the unexercised extremity, the increase in motion in subjects in the contract-relax group was significantly greater than that in the control group. Of the 30 subjects, 29 showed evidence of electrical activity in the contralateral limb when the right lower extremity was contracting against resistance.