Enhanced M1/M2 macrophage ratio promotes orthodontic root resorption

Mechanical force-induced orthodontic root resorption is a major clinical challenge in orthodontic treatment. Macrophages play an important role in orthodontic root resorption, but the underlying mechanism remains unclear. In this study, we examined the mechanism by which the ratio of M1 to M2 macrophage polarization affects root resorption during orthodontic tooth movement. Root resorption occurred when nickel-titanium coil springs were applied on the upper first molars of rats for 3 to 14 d. Positively stained odontoclasts or osteoclasts with tartrate-resistant acid phosphatase were found in resorption areas. Meanwhile, M1-like macrophages positive for CD68 and inducible nitric oxide synthase (iNOS) persistently accumulated on the compression side of periodontal tissues. In addition, the expressions of the M1 activator interferon-γ and the M1-associated pro-inflammatory cytokine tumor necrosis factor (TNF)-α were upregulated on the compression side of periodontal tissues. When the coil springs were removed at the 14th day after orthodontic force application, root resorption was partially rescued. The number of CD68(+)CD163(+) M2-like macrophages gradually increased on the compression side of periodontal tissues. The levels of M2 activator interleukin (IL)-4 and the M2-associated anti-inflammatory cytokine IL-10 also increased. Systemic injection of the TNF-α inhibitor etanercept or IL-4 attenuated the severity of root resorption and decreased the ratio of M1 to M2 macrophages. These data imply that the balance between M1 and M2 macrophages affects orthodontic root resorption. Root resorption was aggravated by an enhanced M1/M2 ratio but was partially rescued by a reduced M1/M2 ratio.

Force-induced Adrb2 in periodontal ligament cells promotes tooth movement

The sympathetic nervous system (SNS) regulates bone resorption through β-2 adrenergic receptor (Adrb2). In orthodontic tooth movement (OTM), mechanical force induces and regulates alveolar bone remodeling. Compressive force-associated osteoclast differentiation and alveolar bone resorption are the rate-limiting steps of tooth movement. However, whether mechanical force can activate Adrb2 and thus contribute to OTM remains unknown. In this study, orthodontic nickel-titanium springs were applied to the upper first molars of rats and Adrb1/2(-/-) mice to confirm the role of SNS and Adrb2 in OTM. The results showed that blockage of SNS activity in the jawbones of rats by means of superior cervical ganglion ectomy reduced OTM distance from 860 to 540 μm after 14 d of force application. In addition, the injection of nonselective Adrb2 agonist isoproterenol activated the downstream signaling of SNS to accelerate OTM from 300 to 540 μm after 7 d of force application. Adrb1/2(-/-) mice showed significantly reduced OTM distance (19.5 μm) compared with the wild-type mice (107.6 μm) after 7 d of force application. Histopathologic analysis showed that the number of Adrb2-positive cells increased in the compressive region of periodontal ligament after orthodontic force was applied on rats. Mechanistically, mechanical compressive force upregulated Adrb2 expression in primary-cultured human periodontal ligament cells (PDLCs) through the elevation of intracellular Ca(2+) concentration. Activation of Adrb2 in PDLCs increased the RANKL/OPG ratio and promoted the peripheral blood mononuclear cell differentiation to osteoclasts in the cocultured system. Upregulation of Adrb2 in PDLCs promoted osteoclastogenesis, which accelerated OTM through Adrb2-enhanced bone resorption. In summary, this study suggests that mechanical force-induced Adrb2 activation in PDLCs contributes to SNS-regulated OTM.

Two biomarker-directed randomized trials in European and Chinese patients with nonsmall-cell lung cancer: the BRCA1-RAP80 Expression Customization (BREC) studies

BACKGROUND

In a Spanish Lung Cancer Group (SLCG) phase II trial, the combination of BRCA1 and receptor-associated protein 80 (RAP80) expression was significantly associated with outcome in Caucasian patients with nonsmall-cell lung cancer (NSCLC). The SLCG therefore undertook an industry-independent collaborative randomized phase III trial comparing nonselected cisplatin-based chemotherapy with therapy customized according to BRCA1/RAP80 expression. An analogous randomized phase II trial was carried out in China under the auspices of the SLCG to evaluate the effect of BRCA1/RAP80 expression in Asian patients.

PATIENTS AND METHODS

Eligibility criteria included stage IIIB-IV NSCLC and sufficient tumor specimen for molecular analysis. Randomization to the control or experimental arm was 1 : 1 in the SLCG trial and 1 : 3 in the Chinese trial. In both trials, patients in the control arm received docetaxel/cisplatin; in the experimental arm, patients with low RAP80 expression received gemcitabine/cisplatin, those with intermediate/high RAP80 expression and low/intermediate BRCA1 expression received docetaxel/cisplatin, and those with intermediate/high RAP80 expression and high BRCA1 expression received docetaxel alone. The primary end point was progression-free survival (PFS).

RESULTS

Two hundred and seventy-nine patients in the SLCG trial and 124 in the Chinese trial were assessable for PFS. PFS in the control and experimental arms in the SLCG trial was 5.49 and 4.38 months, respectively [log rank P = 0.07; hazard ratio (HR) 1.28; P = 0.03]. In the Chinese trial, PFS was 4.74 and 3.78 months, respectively (log rank P = 0.82; HR 0.95; P = 0.82).

CONCLUSION

Accrual was prematurely closed on the SLCG trial due to the absence of clinical benefit in the experimental over the control arm. However, the BREC studies provide proof of concept that an international, nonindustry, biomarker-directed trial is feasible. Thanks to the groundwork laid by these studies, we expect that ongoing further research on alternative biomarkers to elucidate DNA repair mechanisms will help define novel therapeutic approaches.

TRIAL REGISTRATION

NCT00617656/GECP-BREC and ChiCTR-TRC-12001860/BREC-CHINA.

Effects of 20 standard amino acids on the growth, total fatty acids production, and γ-linolenic acid yield in Mucor circinelloides

Twenty standard amino acids were examined as single nitrogen source on the growth, total fatty acids production, and yield of γ-linolenic acid (GLA) in Mucor circinelloides. Of the amino acids, tyrosine gave the highest biomass and lipid accumulation and thus resulted in a high GLA yield with respective values of 17.8 g/L, 23 % (w/w, dry cell weight, DCW), and 0.81 g/L, which were 36, 25, and 72 % higher than when the fungus was grown with ammonium tartrate. To find out the potential mechanism underlying the increased lipid accumulation of M. circinelloides when grown on tyrosine, the activity of lipogenic enzymes of the fungus during lipid accumulation phase was measured. The enzyme activities of glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and ATP-citrate lyase were up-regulated, while NADP-isocitrate dehydrogenase was down-regulated by tyrosine during the lipid accumulation phase of the fungus which suggested that these enzymes may be involved in the increased lipid biosynthesis by tyrosine in this fungus.

Short-term therapeutic drug monitoring of mycophenolic acid reduces infection: a prospective, single-center cohort study in Chinese living-related kidney transplantation

BACKGROUND

The role of therapeutic drug monitoring (TDM) of mycophenolic acid (MPA) in kidney transplant recipients (KTRs) is not clear. We performed a prospective cohort study to evaluate the efficiency of MPA TDM in the Chinese population.

METHODS

A total of 183 living-related KTRs were studied; 101 KTRs received controlled-dose mycophenolate mofetil (MMF) (the CD group), and 82 patients received fixed-dose MMF (the FD group). MPA exposure was measured at days 3, 7, 14, and 30 in the CD group, and at day 30 in the FD group. The primary endpoint was treatment failure (a composite of acute rejection, graft loss, death, or MMF discontinuation) at 12 months post transplantation.

RESULTS

In the CD group, with a starting MMF dose of 2 g/day, approximately 35% of patients had high MPA levels, which were >60 mg × h/L, and mean MPA levels were 59.17 mg × h/L and 61.38 mg × h/L for the CD and FD groups, respectively (P = 0.588). After adjusting MMF dose, MPA exposures in the CD group at day 30 were lower than those in the FD group at day 30 (54.06 vs. 61.38, P = 0.004). At month 12, the CD group had fewer infections (16.8% vs. 31.7%, P = 0.018) with no difference in treatment failure, acute rejection, diarrhea, or anemia.

CONCLUSIONS

KTRs can benefit from short-term TDM of MPA in reducing infection, without increasing acute rejection.

Bacteria in hernia sac: an important risk fact for surgical site infection after incarcerated hernia repair

BACKGROUND

Although some recent reports have proven that incarcerated and/or strangulated hernia is not contraindication to mesh repair, there is still a common concern owing to increased rate of postoperative surgical site infection (SSI). The aim of this clinical study was to evaluate factors that increase the risk of SSI after incarcerated hernia repair, and to identify the pathogens related to SSI.

METHODS

A retrospective analysis was performed on data collected prospectively over a 4-year interval from January 2007 to December 2011. A total of 121 patients who underwent emergency surgery for incarcerated hernias were analyzed.

RESULTS

107 hernias were repaired using mesh versus 14 primary suture repairs. SSIs were observed in 9 of the 121 patients. Of 15 preoperative and intraoperative variables studied, duration of symptoms, diabetes mellitus, present of ileus, bowel resection or mesh repair performed, bacteria present in hernia sac and cloudy fluid in hernia sac were found to be significant factors predicting SSI. On multivariate analysis only bowel resection, duration of symptoms and bacteria present in hernia sac were independent variables. The most common pathogen found in hernia sac and cultured from wound drainage or swab was Escherichia coli. The strains of bacteria cultured from wound drainage or swab were same as those cultured from fluid in hernia sac in six of nine patients.

CONCLUSION

Gut-sourced E. coli is an important common organisms associated with SSI after incarcerated hernia repair. Prosthetic mesh could be used when no bowel resection is performed, duration of symptoms less than 24 h and fluid hernia sac is clear.

Prevention of acute liver allograft rejection by IL-10-engineered mesenchymal stem cells

Hepatic allograft rejection remains a challenging problem, with acute rejection episode as the major barrier for long-term survival in liver transplant recipients. To explore a strategy to prevent allograft rejection, we hypothesized that mesenchymal stem cells (MSCs) genetically engineered with interleukin-10 (IL-10) could produce beneficial effects on orthotopic liver transplantation (OLT) in the experimental rat model. Syngeneic MSCs transduced with IL-10 were delivered via the right jugular vein 30 min post-orthotopic transplantation in the rat model. To evaluate liver morphology and measure cytokine concentration, the blood and liver samples from each animal group were collected at different time-points (3, 5 and 7 days) post-transplantation. The mean survival time of the rats treated with MSCs-IL-10 was shown to be much longer than those treated with saline. According to Banff scheme grading, the saline group scores increased significantly compared with those in the MSCs-IL-10 group. Retinoid acid receptor-related orphan receptor gamma t (RORγt) expression was more increased in the saline group compared to those in the MSCs-IL-10 group in a time-dependent manner; forkhead box protein 3 (FoxP3) expression also decreased significantly in the saline group compared with those in the MSCs-IL-10 group in a time-dependent manner. The expression of cytokines [IL-17, IL-23, IL-6, interferon (IFN)-γ and tumour necrosis factor (TNF)-α] in the saline groups increased significantly compared with the time-point-matched MSCs-IL-10 group, whereas cytokine expression of (IL-10, TGF-β1) was deceased markedly compared to that in the MSCs-IL-10 group. These results suggest a potential role for IL-10-engineered MSC therapy to overcome clinical liver transplantation rejection.

First proficiency testing of second-line anti-tuberculosis drug susceptibility testing in 12 provinces of China

OBJECTIVE

To evaluate the performance of drug susceptibility testing (DST) against the main second-line (SL) anti-tuberculosis drugs in tuberculosis (TB) laboratories in China.

METHOD

The supranational TB reference laboratory issued 30 Mycobacterium tuberculosis isolates to the participating laboratories. Each participating laboratory performed DST against kanamycin (KM), amikacin (AMK), capreomycin (CPM) and ofloxacin (OFX) using the proportion method in Löwenstein-Jensen medium per World Health Organization recommendations. Reported results were checked and compared with the judicial results.

RESULT

The main performance indicators for the four anti-tuberculosis drugs evaluated (KM, AMK, CPM, OFX) were as follows: accordance rates: 91.62%, 99.16%, 96.93% and 96.37%; reproducibility: 99.16%, 99.16%, 94.96% and 94.12%; specificity: 99.12%, 99.64%, 98.00% and 98.41%; sensitivity: 78.03%, 97.62%, 94.44% and 91.51%. The accordance rates and sensitivity values of the four drugs showed statistically significant differences, while specificities showed no significant differences.

CONCLUSION

Eight (66.7%) participating laboratories met the set requirement criteria; however, DST in four (33.3%) laboratories requires greater attention. Of the four drugs tested, the results for KM were lower than those for the other drugs. External quality assessment can lead to effective evaluation of laboratory performance in SL DST.

Expression, purification, and characterization of NADP+-dependent malic enzyme from the oleaginous fungus Mortierella alpina

Malic enzymes are a class of oxidative decarboxylases that catalyze the oxidative decarboxylation of malate to pyruvate and carbon dioxide, with concomitant reduction of NAD(P)+ to NAD(P)H. The NADP+-dependent malic enzyme in oleaginous fungi plays a key role in fatty acid biosynthesis. In this study, the malic enzyme-encoding complementary DNA (cDNA) (malE1) from the oleaginous fungus Mortierella alpina was cloned and expressed in Escherichia coli BL21 (DE3). The recombinant protein (MaME) was purified using Ni-NTA affinity chromatography. The purified enzyme used NADP+ as the cofactor. The K m values for L-malate and NADP+ were 2.19±0.01 and 0.38±0.02 mM, respectively, while the V max values were 147±2 and 302±14 U/mg, respectively, at the optimal condition of pH 7.5 and 33 °C. MaME is active in the presence of Mn2+, Mg2+, Co2+, Ni2+, and low concentrations of Zn2+ rather than Ca2+, Cu2+, or high concentrations of Zn2+. Oxaloacetic acid and glyoxylate inhibited the MaME activity by competing with malate, and their K i values were 0.08 and 0.6 mM, respectively.

Increased fatty acid unsaturation and production of arachidonic acid by homologous over-expression of the mitochondrial malic enzyme in Mortierella alpina

Malic enzyme (ME) catalyses the oxidative decarboxylation of L-malate to pyruvate and provides NADPH for intracellular metabolism, such as fatty acid synthesis. Here, the mitochondrial ME (mME) gene from Mortierella alpina was homologously over-expressed. Compared with controls, fungal arachidonic acid (ARA; 20:4 n-6) content increased by 60 % without affecting the total fatty acid content. Our results suggest that enhancing mME activity may be an effective mean to increase industrial production of ARA in M. alpina.

The structure of the symptoms of major depression: exploratory and confirmatory factor analysis in depressed Han Chinese women

BACKGROUND

The symptoms of major depression (MD) are clinically diverse. Do they form coherent factors that might clarify the underlying nature of this important psychiatric syndrome?

METHOD

Symptoms at lifetime worst depressive episode were assessed at structured psychiatric interview in 6008 women of Han Chinese descent, age ⩾30 years with recurrent DSM-IV MD. Exploratory factor analysis (EFA) and confirmatoryfactor analysis (CFA) were performed in Mplus in random split-half samples.

RESULTS

The preliminary EFA results were consistently supported by the findings from CFA. Analyses of the nine DSM-IV MD symptomatic A criteria revealed two factors loading on: (i) general depressive symptoms; and (ii) guilt/suicidal ideation. Examining 14 disaggregated DSM-IV criteria revealed three factors reflecting: (i) weight/appetite disturbance; (ii) general depressive symptoms; and (iii) sleep disturbance. Using all symptoms (n = 27), we identified five factors that reflected: (i) weight/appetite symptoms; (ii) general retarded depressive symptoms; (iii) atypical vegetative symptoms; (iv) suicidality/hopelessness; and (v) symptoms of agitation and anxiety.

CONCLUSIONS

MD is a clinically complex syndrome with several underlying correlated symptom dimensions. In addition to a general depressive symptom factor, a complete picture must include factors reflecting typical/atypical vegetative symptoms, cognitive symptoms (hopelessness/suicidal ideation), and an agitated symptom factor characterized by anxiety, guilt, helplessness and irritability. Prior cross-cultural studies, factor analyses of MD in Western populations and empirical findings in this sample showing risk factor profiles similar to those seen in Western populations suggest that our results are likely to be broadly representative of the human depressive syndrome.