Prognostic factors for colorectal cancer patients with pulmonary metastases

e15107

Background: Pulmonary is the second common metastastic site of CRC with a good survival after metastasectomy, however the general situation of pulmonary metastases from CRC has received little attention, especially for unresectable ones. The aim of this study was to determine factors that may influence survival and disease free interval from primary radical surgery to pulmonary metastases (DFI). Methods: From 01/2000 to 11/2008, a total of 206 pts with pulmonary metastases (colon72, rectal ca131, 3 unknown) were collected retrospectively and the clinical data were analyzed using Kaplan-Meier survival curves, univariate and multivariate analysis. Results: 128 pts (62.1%) had lung disease as the first metastatic site and 33 pts (26.7%) had synchronous liver involvement. Only 17 patients (8.3%) followed pulmonary metastatic resection, and others underwent palliative medical treatment including the chemotherapy and intervention. Median survival was 16.0 months (range 12.240–19.760) with a 18% 5-year survival. Of the totally 160 patients who had synchronous pulmonary metastases after radical primary tumor surgery, the mDFI was 20 months (range 16.738–23.262) months. Rectal cancer had a high chance (65%) for lung recurrence with longer DFI (21 vs 14 mo, P=0.02), but no difference of survival was shown compared to colon cancer. Factors that significantly predicted a poor prognosis on univariate analysis included vessel invasion (P=0.022) and high T stage (P=0.009), but neither of them was the independent prognostic factors after multivariate analysis. The factors influencing the DFI of metachronous pulmonary metastases included primary tumor site, pathological morphology, tumor infiltration stage and regional lymph node stage (P<0.05). There was a trend of better survival of patients receiving resection surgery after pulmonary metastases than receiving chemotherapy alone though no statistical significant was reached (mOS:34 vs 16 mo, P=0.125). But to patients who receiving metastatic site resection, chemotherapy after surgery improved the survival (P=0.042). Conclusions: No independent prognostic factors of survival had been found. The invasive tumor with high stage may have a shorter disease free interval of pulmonary metastases after primary surgery.

No significant financial relationships to disclose.

Fabrication and biological characteristics of beta-tricalcium phosphate porous ceramic scaffolds reinforced with calcium phosphate glass

The fabrication process, compressive strength and biocompatibility of porous beta-tricalcium phosphate (beta-TCP) ceramic scaffolds reinforced with 45P(2)O(5)-22CaO-25Na(2)O-8MgO bioglass (beta-TCP/BG) were investigated for their suitability as bone engineering materials. Porous beta-TCP/BG scaffolds with macropore sizes of 200-500 muicrom were prepared by coating porous polyurethane template with beta-TCP/BG slurry. The beta-TCP/BG scaffolds showed interconnected porous structures and exhibited enhanced mechanical properties to those pure beta-TCP scaffolds. In order to assess the effects of chemical composition of this bioglass on the behavior of osteoblasts cultured in vitro, porous scaffolds were immersed in simulated body fluid (SBF) for 2 weeks, and original specimens (without soaked in SBF) seeded with MC3T3-E1 were cultured for the same period. The ability of inducing apatite crystals in simulated body fluid and the attachment of osteoblasts were examined. Results suggest that apatite agglomerates are formed on the surface of the beta-TCP/BG scaffolds and its Ca/P molar ratio is approximately 1.42. Controlling the crystallization from the beta-TCP/BG matrix could influence the releasing speed of inorganic ions and further adjust the microenvironment of the solution around the beta-TCP/BG, which could improve the interaction between osteoblasts and the scaffolds.

Inhibition of protein deacetylation by trichostatin A impairs microtubule-kinetochore attachment

Inhibition of protein deacetylation arrests cells in mitosis, but the mechanism is unknown. To understand why inhibiting protein deacetylation causes cell cycle arrest, we treated HeLa cells beyond G1/S transition with trichostatin A (TSA), a potent protein deacetylase inhibitor, and found that the cells arrested at prometaphase with ectopic spindles and unaligned chromosomes. The hyper-acetylated cells encountered a serious microtubule (MT)-kinetochore attachment problem, although the kinetochores are intact at ultrastructural level. By immunofluorescence staining of kinetochore proteins, we found that the pericentromeric H3K9Me3-HP1 pathway was disrupted and that the CENP-A-dependent outer plate protein dynamics of kinetochores was greatly diminished by the drug treatment. The treatment also caused the loss of chromosome passenger complex (CPC), the proposed error checking system, from centromere and impaired the microtubule dynamics of the cells. Overall, we propose that deacetylation inhibition impairs MT-kinetochore attachment through disrupting the centromere function and altering the kinetochore composition and MT dynamics.

Relation between nuclear envelope and nuclear lamina in nuclear assembly in vitro

Xenopus laevis egg extracts cell-free nuclear assembly system was used as an experimental model to study the process of nuclear lamina assembly in nuclear reconstitution in vitro. The experimental results showed that lamin was involved in the nuclear assembly in vitro. The assembly of nuclear lamina was preceded by the assembly of nuclear matrix, and probably, inner nuclear matrix assembly provided the basis for nuclear lamina assembly. Inhibition of normal assembly of nuclear lamina, by preincubating egg extracts cell-free system with anti-lamin antibodies, resulted in abnormal assembly of nuclear envelope, suggesting that nuclear envelope assembly is closely associated with nuclear lamina assembly.

The oligopeptide (opp) gene cluster of Streptococcus mutans: identification, prevalence, and characterization

INTRODUCTION

The Opp system is an ATP-binding cassette-type transporter formed by membrane-associated proteins required for the uptake of oligopeptides in bacteria. In gram-positive bacteria, the Opp system, and particularly the oligopeptide-binding protein (OppA), has been shown to be involved in different aspects of cell physiology, including intercellular communication and binding to host proteins.

METHODS

In the present study we began to investigate the Opp system of Streptococcus mutans, the main etiological agent of dental caries.

RESULTS

Five opp genes (oppABCDF) organized in a single operon were identified in the genome of the S. mutans UA159 strain. Amino acid sequence analyses showed that the S. mutans OppA is closely related to an ortholog found in Streptococcus agalactiae. Incubation of S. mutans UA159 cells with an anti-OppA-specific serum did not inhibit biofilm formation on polystyrene plates. Moreover, S. mutans UA159 derivatives carrying deletions on the oppA or oppB genes did not show significant growth impairment, increased sensitivity to aminopterin, or defective capacity to form biofilms on polystyrene wells in the presence or not of saliva. Remarkably, only two out of three laboratory strains and one out of seven clinical strains recovered from tooth decay processes harbored a copy of the oppA gene and expressed the OppA protein.

CONCLUSION

Collectively, these results indicate that, in contrast to other Streptococcus species, the S. mutans Opp system, and particularly the OppA protein, does not represent an important trait required for growth and colonization.

Strategies to design inhibitors of Clostridium botulinum neurotoxins

Botulinum neurotoxins (BoNTs), produced by spore-forming anaerobic Clostridium botulinum, are the most toxic substances known. They cause the life-threatening disease botulism, characterized by flaccid muscle paralysis. While the natural cases of botulism are rare, due to their extreme toxicity and easy production, BoNTs have become potential biowarfare agents, and create maximum fear among populations concerned with bioterror agents. The only available antidote against BoNTs is equine antitoxin. Equine antitoxin can only target the toxins at extracellular level, and can not reverse the paralysis caused by botulism. In addition, equine antibody can cause severe hypersensitivity reactions, and is limited to be used for prophylaxis treatment. BoNTs are large proteins with three distinct domains, the binding domain, the translocation domain, and the enzymatic domain with highly specific endopeptidase activity to cleave the proteins involved the neurotransmitter release. Targeting any of these domains can inhibit the functions of BoNT. Humanized monoclonal antibodies, small peptides and peptide mimetics, receptor mimics, and small molecules targeting the endopeptidase activity have emerged as potential new inhibitors against BoNTs. With the structure of BoNT resolved, molecular modeling and rational design of potent antidotes against botulism is on the horizon. An area that has not been explored for designing the antidotes against botulism is aptamers, which have been successfully developed as therapeutics in several areas. This review will focus on some of these new strategies to design effective antidotes against botulism. The strategies reviewed in this article can be easily applied to design inhibitors for other bacterial toxins.

Systemic and Myocardial Oxygen Transport Responses to Brain Death in Pigs

BACKGROUND

Brain death is associated with profound disturbances of systemic and myocardial oxygen transport, but little is known regarding the acute response of systemic oxygen consumption (VO(2)).

METHODS

Brain death was induced in 6 pigs (30.6 +/- 3.0 kg) by balloon inflation into the cranial cavity. VO(2) was continuously measured by respiratory mass spectrometry. Blood pressures and gases were measured from the aorta, superior vena cava, and coronary sinus, with arterial epinephrine and norepinephrine, prior to brain death, at 1, 10, and 90 minutes after brain death. Cardiac output (CO), systemic vascular resistance (SVR), oxygen delivery (DO(2)), oxygen extraction (EO(2)), and myocardial oxygen (mEO(2)) and lactate extractions (mE(1ac)) were calculated. Left ventricular contractility was assessed by micromanometer tipped catheters.

RESULTS

VO(2) increased from 4.8 +/- 0.9 to 6.3 +/- 0.9 mL/min/kg 1 minute after brain death (P < .001), and subsequently decreased to below baseline at 90 minutes (P < .001). Left ventricular contractility, CO, and DO(2) increased 1 minute after brain death (P < .001), followed by a rapid decrease to baseline within 10 minutes (P < .001). SVR and EO(2) decreased after brain death (P < .01) and remained low. Lactate remained unchanged. mE(1ac) decreased after brain death despite a decrease in mEO(2) (P < .01), and returned to baseline at 90 minutes.

CONCLUSIONS

The initial surge in VO(2) after brain death is offset by the greater increase in DO(2), thus tissue perfusion remains adequate. The lower than baseline VO(2) and SVR at the end of the study period may indicate general metabolic and hemodynamic compromise. The information regarding the profound metabolic alterations imposed by brain death may have implications for management of brain death donors.

The discovery of tetrahydrofluorenones as a new class of estrogen receptor beta-subtype selective ligands

Synthesis and derivatization of a series of substituted tetrahydrofluorenone analogs giving potent, ERbeta subtype selective ligands are described. Several analogs possessing ERbeta binding affinities comparable to 17beta-estradiol but with greater than 75-fold selectivity over ERalpha are reported.

Assessment of the relationship between cerebral and splanchnic oxygen saturations measured by near-infrared spectroscopy and direct measurements of systemic haemodynamic variables and oxygen transport after the Norwood procedure

OBJECTIVES

To evaluate the clinical utility of near-infrared spectroscopic (NIRS) monitoring of cerebral (ScO2) and splanchnic (SsO2) oxygen saturations for estimation of systemic oxygen transport after the Norwood procedure.

METHODS

ScO2 and SsO2 were measured with NIRS cerebral and thoracolumbar probes (in humans). Respiratory mass spectrometry was used to measure systemic oxygen consumption (O2). Arterial (SaO2), superior vena caval (SvO2) and pulmonary venous oxygen saturations were measured at 2 to 4 h intervals to derive pulmonary (Qp) and systemic blood flow (Qs), systemic oxygen delivery (DO2) and oxygen extraction ratio (ERO2). Mixed linear regression was used to test correlations. A study of 7 pigs after cardiopulmonary bypass (study 1) was followed by a study of 11 children after the Norwood procedure (study 2).

RESULTS

Study 1. ScO2 moderately correlated with SvO2, mean arterial pressure, Qs, DO2 and ERO2 (slope 0.30, 0.64. 2.30, 0.017 and -32.5, p < 0.0001) but not with SaO2, arterial oxygen pressure (PaO2), haemoglobin and O2. Study 2. ScO2 correlated well with SvO2, SaO2, PaO2 and mean arterial pressure (slope 0.43, 0.61, 0.99 and 0.52, p < 0.0001) but not with haemoglobin (slope 0.24, p > 0.05). ScO2 correlated weakly with O2 (slope -0.07, p = 0.05) and moderately with Qs, DO2 and ERO2 (slope 3.2, 0.03, -33.2, p < 0.0001). SsO2 showed similar but weaker correlations.

CONCLUSIONS

ScO2 and SsO2 may reflect the influence of haemodynamic variables and oxygen transport after the Norwood procedure. However, the interpretation of NIRS data, in terms of both absolute values and trends, is difficult to rely on clinically.

Comparative studies on the roles of mediator molecules in expression of the suppressor activity of Mycobacterium avium complex-induced immunosuppressive macrophages against T cell and B cell mitogenic responses

Mycobacterium avium complex-induced immunosuppressive macrophages (MAC-MPhis) exhibit suppressor activity against concanavalin A-induced T cell mitogenesis (T cell Con A mitogenesis). We examined the profiles of the MAC-MPhi-mediated suppression of lipopolysaccharide-induced B cell mitogenesis (B cell LPS mitogenesis) and found the following. First, although N(G)-monomethyl-L-arginine and carboxy-PTIO effectively blocked the MAC-MPhi's suppressor activity against T cell Con A mitogenesis, MAC-MPhi's action against B cell LPS mitogenesis was only weakly affected by these NO-reducing agents. Second, B cell LPS mitogenesis was remarkably more susceptible to MAC-MPhi-derived reactive oxygen intermediates than T cell Con A mitogenesis. Third, B cell LPS mitogenesis was less susceptible to the inhibitory effects of the other MAC-MPhi-derived suppressor mediators, including free fatty acids, TGF-beta and prostaglandin E(2), than T cell Con A mitogenesis. Fourth, MAC-MPhi's suppressor activity was strongly dependent on B7-1 like molecule-mediated cell contact with target cells only in the case of T cell Con A mitogenesis. Therefore, there are significant differences in the modes of suppressor action of MAC-MPhis against T cell and B cell mitogenesis.

Targeted nNOS gene transfer into the cardiac vagus rapidly increases parasympathetic function in the pig

Nitric oxide (NO) derived from neuronal nitric oxide synthase (nNOS) facilitates cardiac vagal neurotransmission and bradycardia in vitro. Here we provide evidence of rapid (within 9 h) protein expression and increased vagal responsiveness in vivo following targeted gene transfer of nNOS into the cardiac vagus of the pig. Right vagi were injected with vector encoding nNOS (Ad.nNOS) or saline, while left vagi received an injection of vector encoding enhanced green fluorescent protein (Ad.eGFP). Enhanced nNOS protein expression was detected exclusively in the right vagus nerve, with no evidence of iNOS expression. This was associated with increased baroreflex sensitivity and greater heart rate responsiveness to right vagal stimulation. In contrast, responsiveness of left vagi, or sham-injected right vagi remained constant over the same time period. Basal heart rate was unchanged following gene transfer, suggesting no change in vagal tone. These results support the pre-/post-ganglionic synapse as a site for NO-mediated facilitation of vagal bradycardia in the pig. In addition they demonstrate in vivo that functional gene expression induced with adenoviral vectors occurs earlier than first thought, and may therefore, provide a novel intervention to acutely modulate the neural control of cardiac excitability.

Endothelial nitric oxide synthase dysfunction in diabetic mice: importance of tetrahydrobiopterin in eNOS dimerisation

AIMS/HYPOTHESIS

Impaired nitric oxide (NO) bioactivity and increased superoxide (SO) production are characteristics of vascular endothelial dysfunction in diabetes. The underlying mechanisms remain unknown. In this regard, we investigated the role of tetrahydrobiopterin (BH4) bioavailability in regulating endothelial nitric oxide synthase (eNOS) activity, dimerisation and SO production in streptozotocin-induced diabetic mice.

METHODS

Mouse aortas were used for assays of the following: (1) aortic function by isometric tension; (2) NO by electronic paramagnetic resonance; (3) SO by lucigenin-enhanced chemiluminescence and dihydroethidine fluorescence; (4) total biopterin and BH4 by high-performance liquid chromatography; and (5) eNOS protein expression and dimerisation by immunoblotting.

RESULTS

In diabetic mouse aortas, relaxations to acetylcholine and NO levels were significantly decreased, but SO production was increased, in association with reductions in total biopterins and BH4. Although total eNOS levels were increased in diabetes, the protein mainly existed in monomeric form. Conversely, specifically augmented BH4 in diabetic endothelium preserved eNOS dimerisation, but the expression remained unchanged.

CONCLUSIONS/INTERPRETATION

Our results demonstrate that BH4 plays an important role in regulating eNOS activity and its functional protein structure, suggesting that increasing endothelial BH4 and/or protecting it from oxidation may be a rational therapeutic strategy to restore eNOS function in diabetes.

Effect of endodontic procedures on enterococci, enteric bacteria and yeasts in primary endodontic infections

AIM

To detect enterococci, enteric bacteria and yeast species from the canals of teeth with primary endodontic infections before and after canal preparation and to test the antibiotic susceptibility of enterococcal strains isolated from infected root canals.

METHODOLOGY

Twenty-five single-rooted teeth with pulp necrosis, intact pulp chambers and periradicular lesions were selected for study. Samples were collected from canals before and after instrumentation. Amongst isolated microorganisms from infected root canals only enterococci, enteric bacteria and yeasts were identified by biochemical tests. The in vitro antimicrobial susceptibility of isolated enterococci strains was evaluated by the Etest system.

RESULTS

Microorganisms were isolated from 92% of the samples following intracoronal access, 22% were enterococci, enteric bacteria or yeast species. After biomechanical preparation, these species were no longer detected. After 7 days without intracanal dressing, 100% of the canals contained microorganisms, 52% of which were target species. However, after using paramonochlorophenol [PRP (2.0 g), Rinosoro and polyethylene glycol (400 equal parts up to 100 mL)] as an intracanal dressing for 7 days, enteric bacteria and yeasts were not detected; only enterococci were still present. All strains of enterococci were susceptible to ampicillin, but exhibited variable susceptibility to rifampin and ciprofloxacin.

CONCLUSIONS

Enterococci, enteric bacteria and yeasts were present in primary endodontic infections. Enterococci, particularly Enterococcus faecalis and E. faecium were resistant to removal by root canal preparation followed by intracanal dressing.

In vitro antimicrobial effect of bacteriophages on human dentin infected with Enterococcus faecalis ATCC 29212

This study assessed the effect of bacteriophages on the viability of Enterococcus faecalis. Human dental roots were inoculated with a suspension of E. faecalis at three different multiplicities of infection - 0.1, 1.0 and 10.0. The phage lysate was able to significantly inhibit bacteria growth when incubated at the multiplicities of infection of 1.0, 10.0 and 0.1. The dental roots were also inoculated with bacteria for 6 days to allow bacterial penetration into the teeth tubules. Addition of the phage lysate to the roots following the 6-day incubation period led to a substantial reduction in bacteria viability. Phage therapy may be an important alternative for the treatment of root canal infections refractory to conventional endodontic therapy.

Impaired regulation of neuronal nitric oxide synthase and heart rate during exercise in mice lacking one nNOS allele

We tested the hypothesis that a single allele deletion of neuronal nitric oxide synthase (nNOS) would impair the neural control of heart rate following physical training, and that this phenotype could be restored following targeted gene transfer of nNOS. Voluntary wheel-running (+EX) in heterozygous nNOS knockout mice (nNOS(+/-), +EX; n= 52; peak performance 9.1 +/- 1.8 km day(-1)) was undertaken and compared to wild-type mice (n= 38; 9.5 +/- 0.8 km day(-1)). In anaesthetized wild-type mice, exercise increased phenylephrine-induced bradycardia by 67% (measured as heart rate change, in beats per minute, divided by the change in arterial blood pressure, in mmHg) or pulse interval response to phenylephrine by 52% (measured as interbeat interval change, in milliseconds, divided by the change in blood pressure). Heart rate changes or interbeat interval changes in response to right vagal nerve stimulation were also enhanced by exercise in wild-type atria (P < 0.05), whereas both in vivo and in vitro responses to exercise were absent in nNOS(+/-) mice. nNOS inhibition attenuated heart rate responses to vagal nerve stimulation in all atria (P < 0.05) and normalized the responses in wild-type, +EX with respect to wild-type with no exercise (-EX) atria. Atrial nNOS mRNA and protein were increased in wild-type, +EX compared to wild-type, -EX (P < 0.05), although exercise failed to have any effect in nNOS(+/-) atria. In vivo nNOS gene transfer using adenoviruses targeted to atrial ganglia enhanced choline acetyltransferase-nNOS co-localization (P < 0.05) and increased phenylephrine-induced bradycardia in vivo and heart rate responses to vagal nerve stimulation in vitro compared to gene transfer of enhanced green fluorescent protein (eGFP, P < 0.01). This difference was abolished by nNOS inhibition (P < 0.05). In conclusion, genomic regulation of NO bioavailability from nNOS in cardiac autonomic ganglia in response to training is dependent on both alleles of the gene. Although basal expression of nNOS is normal, polymorphisms of nNOS may interfere with neural regulation of heart rate following training. Targeted gene transfer of nNOS can restore this impairment.

Comparative antimicrobial activities of gatifloxacin, sitafloxacin and levofloxacin against Mycobacterium tuberculosis replicating within Mono Mac 6 human macrophage and A-549 type II alveolar cell lines

Mycobacterium tuberculosis (MTB) is capable of invading not only macrophages (Mphis) but also type II pneumocytes. In this study, we compared the antimicrobial activities of fluoroquinolones, including gatifloxacin, sitafloxacin and levofloxacin, against the MTB replication in the Mono Mac 6 human Mphi cell line (MM6-Mphis) and the A-549 human type II alveolar epithelial cell line (A-549 cells). When test quinolones were added at the MIC (0.125, 0.06 and 0.25 mg/l for gatifloxacin, sitafloxacin and levofloxacin, respectively) to the culture media of MTB-infected cells, these drugs exerted growth-inhibitory activity against intracellular organisms in the order of sitafloxacin > gatifloxacin > levofloxacin. On the other hand, when test quinolones were added at Cmax in the blood (1.7, 1.0 and 2.0 mg/l for gatifloxacin, sitafloxacin and levofloxacin, respectively), these drugs exhibited bactericidal activity against intracellular MTB in the order of gatifloxacin > sitafloxacin > or = levofloxacin. In addition, when test drugs were added at 1/8 C(max) to 1/2 C(max), the efficacy was in the order of sitafloxacin > gatifloxacin > levofloxacin. Thus, it appears that the MIC values of fluoroquinolones are not always predictive of their antimicrobial activity against intracellular MTB. In this context, it was also found that intracellular uptake of these quinolones by MM6-Mphis and A-549 cells was in the order of sitafloxacin > gatifloxacin > levofloxacin. This implies that the cellular permeability of these quinolones is an important factor that determines their efficacy to eliminate intracellular MTB organisms.

Molecular characterization of a distinct potyvirus from whitegrass in China

Apotyvirus isolated from perennial whitegrass ( Pennisetum centrasiaticum Tzvel.) in North China was characterized at the molecular level. The 3' terminal nucleotide (nt) sequence of 1669 nt of the viral RNA genome has been determined, which covered the coding region of the C-terminal part of the large nuclear inclusion protein (NIb, RNA polymerase), capsid protein (CP) gene and the 3' nontranslated region (NTR). The CP gene consisted of 909 nt (including the stop codon) encoding 302 amino acid residues, and the 3' NTR was 241 nt in length excluding the polyadenylated tract. Sequence comparison of the amino acids of CPs showed that this virus was most closely related to Sorghum mosaic virus and Maize dwarf mosaic virus with percent identities of 77% to 78% while that of the 3' NTRs suggested that it was most closely related to Zea mosaic virus with identity of 72%. This virus isolate was to some extent closely related to other members of the Sugarcane mosaic virus subgroup of potyviruses for the CP amino acid sequences. Phylogenetic analyses of the sequences indicated that this virus isolate represented a distinct potyvirus, and the name Pennisetum mosaic virus (PenMV) is proposed.

Efficacy of a 0.5% chlorhexidine gel on the control of gingivitis in Brazilian mentally handicapped patients

OBJECTIVE

To evaluate the effectiveness of a 0.5% chlorhexidine gel on the reduction of interdental gingival bleeding.

MATERIAL AND METHODS

Forty-three mentally handicapped subjects, living in an institution (Casas André Luiz, Brazil), were enrolled in a double-blind randomised clinical trial. The subjects were randomly divided into two groups: test (chlorhexidine gel) and control (placebo gel). The gel was applied with trays, twice a day, over a period of 8 weeks. The interdental bleeding index (IBI) was recorded before and after the period in which the gel was used.

RESULTS

Statistical analysis showed that baseline IBI scores were similar (p=0.82) for test and control groups (55.6% and 54.5%, respectively). After 8 weeks, a statistically significant (p<0.001) decrease in IBI means took place in the test group (33.2%). The control group presented a small increase (60.6%) in IBI scores. The difference between groups was significant at the end of the study (p<0.001).

CONCLUSION

The results indicated that the use of a 0.5% chlorhexidine gel was effective in reducing interdental gingival bleeding in special patients.