[Simultaneous detection of 7 important Rickettsiales pathogens by TaqMan-probe quantitative real-time PCR]

Objective: To establish and optimize a TaqMan-probe quantitative real-time PCR (qPCR) assay for the detection of 7 important Rickettsiales pathogens and simultaneous identification of the infection types. Methods: Based on the ompB gene of Rickettsia prowazekii, Rickettsia mooseri and spotted fever group rickettsiae, the groEL gene of Orientia tsutsugamushi, the 16S rRNA of Ehrlichia chaffeensis, the gltA gene of Anaplasma phagocytophilum and the com1 gene of Coxiella burnetii, we synthesized primers and TaqMan-probes and optimized the reaction system and reaction process to same solution. The sensitivity, specificity and reproducibility of this assay were evaluated and the assay was used for the detection of simulated and actual samples. Results: The Ct value of the standard curves of the 7 pathogens showed a good linear relationship with the number of DNA copies (all R² >0.990 0), the minimum detection limit was 10 copies/μl, showing good specificity. In the 96 tick nucleic acid extracts, Coxiella burnetii was detected in 1 sampleand spotted fever group Rickettsiae was detected in 3 samples. In the 80 blood samples from patients with undefined febrile illness, Orientia tsutsugamushi was detected in 1 sample and spotted fever group rickettsiae was detected in 2 samples. Conclusions: In this study, based on the established TaqMan-probe qPCR assay, the reaction system and reaction condition of the 7 important pathogens of Rickettsiales were optimized to the same solution. This method overcomes the shortcomings of using different reaction systems and reaction conditions for different pathogens, which can precisely identify the species of 7 important pathogens of Rickettsiales in clinical sample detections and is important for the infection type identification and laboratory detection time reduction to facilitate precise treatment of the patients.

A novel approach for developing left bundle branch pacing and left bundle branch block in a canine model

BACKGROUND AND OBJECTIVE

Left bundle branch pacing (LBBP) has shown the benefits in the treatment of dyssynchronous heart failure (HF). The purpose of this study was to develop a novel approach for LBBP and left bundle branch block (LBBB) in a canine model.

METHODS

A "triangle-center" method by tricuspid valve annulus angiography for LBBP implantation was performed in 6 canines. A catheter was then applied for retrograde His potential recording and left bundle branch (LBB) ablation simultaneously. The conduction system was stained to verify the "triangle-center" method for LBBP and assess the locations of the LBB ablation site in relation to the left septal fascicle (LSF).

RESULTS

The mean LBB potential to ventricular interval and stimulus-peak left ventricular activation time were 11.8 ± 1.2 and 35.7 ± 3.1 ms, respectively. The average intrinsic QRS duration was 44.7 ± 4.7 ms. LBB ablation significantly prolonged the QRS duration (106.3 ± 8.3 ms, p < .001) while LBBP significantly shortened the LBBB-QRS duration to 62.5 ± 5.3 ms (p < .001). After 6 weeks of follow-up, both paced QRS duration (63.0 ± 5.4 ms; p = .203) and LBBB-QRS duration (107.3 ± 7.4 ms; p = .144) were unchanged when comparing to the acute phase, respectively. Anatomical analysis of 6 canine hearts showed that the LBBP lead-tip was all placed in LSF area.

CONCLUSION

The new approach for LBBP and LBBB canine model was stable and feasible to simulate the clinical dyssynchrony and resynchronization. It provided a useful tool to investigate the basic mechanisms of underlying physiological pacing benefits.

The mediation function of resting heart rate in how physical activity improves all-cause mortality: Continuous and automatic measurement via cardiac implantable electronic devices

Background

Physical activity (PA) and resting heart rate (RHR) are connected with all-cause mortality. Moreover, there was an inverse correlation between PA and RHR. However, the causal relationship between PA, RHR, and long-term mortality has been rarely evaluated and quantified, particularly the mediation effect of RHR in the association between PA and all-cause mortality.

Objective

To describe the relationship between PA and RHR when consistently measured via cardiac implantable electronic devices (CIED) and further explore the mediation effect of PA on all-cause mortality through RHR.

Materials and methods

Patients who underwent CIED implantation and received remote home monitoring services were included. During the first 30–60 days after CIED implantation, daily PA and RHR were continuously measured and automatically transmitted by CIED. The primary endpoint was all-cause mortality. The multiple linear regression model was used to confirm the relationship between PA and RHR. The predictive values of both PA and RHR for all-cause mortality were assessed by multivariable Cox proportional hazards models. The causal mediation model was further established to verify and quantify the mediation effect of RHR in the association between PA and all-cause mortality.

Results

A total of 730 patients with CIED were included. The mean daily PA and RHR were 10.7 ± 5.7% and 61.3 ± 9.1 bpm, respectively. During a mean follow-up period of 55.8 months, 187 (26.5%) death was observed. A negative linear relationship between PA and RHR was demonstrated in the multiple regression model (β = −0.260; 95% CI: −0.377 to −0.143, p < 0.001). Multivariable Cox proportional hazards analysis showed that both lower levels of PA (HR = 0.907; 95% CI: 0.878–0.936, p < 0.001) and higher RHR (HR = 1.016; 95% CI: 1.001–1.032, P = 0.031) were independent risk factors of all-cause mortality. Causal mediation analysis further confirmed and quantified the mediation function of RHR in the process of PA improving all-cause mortality (mediation proportion = 3.9%; 95% CI: 0.2–10.0%, p = 0.036).

Conclusion

The effects of the higher level of PA on improving life prognosis may be partially mediated through RHR among patients with CIED. It indicates that changes in the autonomic nervous function during postoperative rehabilitation exercises should get more attention.

Monitoring mild cognitive impairment of workers exposed to occupational aluminium based on quantitative susceptibility mapping

AIM

To investigate the diagnostic value of quantitative susceptibility mapping (QSM) in mild cognitive impairment (MCI) of aluminium (Al) workers.

MATERIALS AND METHODS

The basic data of 53 workers in an Al factory were collected and divided into the MCI group and normal control (NC) group by Montreal Cognitive Assessment (MoCA) scores. All participants were tested for plasma Al concentration and had magnetic resonance imaging (MRI). The QSM values of many areas of the brain were delineated and measured. Independent two-sample t-tests or non-parametric tests were used to compare the parameter values between the two groups. Spearman's correlation analysis was performed between QSM values, MoCA scores, and plasma Al concentration. The receiver operating characteristic curve and z test were performed to assess diagnostic efficacy and the best parameter.

RESULTS

There was no difference in age and educational level. Plasma Al concentration of the MCI group was higher than that of NC group (p=0.057). QSM values of the left hippocampus, left dentate nucleus, right substantia nigra, and left putamen in MCI group were higher than that of NC group (p<0.05), and the left hippocampus had the best diagnostic efficacy. QSM values correlated negatively with MoCA scores. No correlation was found between QSM values and plasma Al concentration (p>0.05).

CONCLUSION

QSM might be a neuroimaging marker for the diagnosis of MCI. The left hippocampus showed the best diagnostic efficacy. Plasma Al concentration of the MCI group was higher than that of the NC group. A correlation between QSM and plasma Al concentration was not found.

Long-term treadmill exercise improves spatial memory of male APPswe/PS1dE9 mice by regulation of BDNF expression and microglia activation

Increasing evidence suggests that physical activity could delay or attenuate the symptoms of Alzheimer's disease (AD). But the underlying mechanisms are still not fully understood. To investigate the effect of long-term treadmill exercise on the spatial memory of AD mice and the possible role of β-amyloid, brain-derived neurotrophic factor (BDNF) and microglia in the effect, male APPswe/PS1dE9 AD mice aged 4 months were subjected to treadmill exercise for 5 months with 6 sessions per week and gradually increased load. A Morris water maze was used to evaluate the spatial memory. Expression levels of β-amyloid, BDNF and Iba-1 (a microglia marker) in brain tissue were detected by immunohistochemistry. Sedentary AD mice and wildtype C57BL/6J mice served as controls. The results showed that 5-month treadmill exercise significantly decreased the escape latencies (P < 0.01 on the 4th day) and improved the spatial memory of the AD mice in the water maze test. Meanwhile, treadmill exercise significantly increased the number of BDNF-positive cells and decreased the ratios of activated microglia in both the cerebral cortex and the hippocampus. However, treadmill exercise did not significantly alleviate the accumulation of β-amyloid in either the cerebral cortex or the hippocampus of the AD mice (P > 0.05). The study suggested that long-term treadmill exercise could improve the spatial memory of the male APPswe/PS1dE9 AD mice. The increase in BDNF-positive cells and decrease in activated microglia might underpin the beneficial effect.

Involvement of regulatory volume decrease in the migration of nasopharyngeal carcinoma cells

The transwell chamber migration assay and CCD digital camera imaging techniques were used to investigate the relationship between regulatory volume decrease (RVD) and cell migration in nasopharyngeal carcinoma cells (CNE-2Z cells). Both migrated and non-migrated CNE-2Z cells, when swollen by 47% hypotonic solution, exhibited RVD which was inhibited by extracellular application of chloride channel blockers adenosine 5'-triphosphate (ATP), 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) and tamoxifen. However, RVD rate in migrated CNE-2Z cells was bigger than that of non-migrated cells and the sensitivity of migrated cells to NPPB and tamoxifen was higher than that of non-migrated cells. ATP, NPPB and tamoxifen also inhibited migration of CNE-2Z cells. The inhibition of migration was positively correlated to the blockage of RVD, with a correlation coefficient (r) = 0.99, suggesting a functional relationship between RVD and cell migration. We conclude that RVD is involved in cell migration and RVD may play an important role in migratory process in CNE-2Z cells.

[Regulatory volume decrease and its mechanism in nasopharyngeal epithelial cells]

To investigate regulatory volume decrease (RVD) and its mechanism in primary-culturing fetal human nasopharyngeal epithelial cells, living cell imaging technique was employed to detect the volume changes following exposure to hypotonic solution, and blockage of Cl- channels was used to clarify the role of Cl- channels in RVD. The results showed that extracellular hypotonic treatment swelled the cells and induced RVD. 47% hypotonic solution (160 mOsmol/L) swelled the cell by 144.7% and induced 38.7% recovery of cell volume within 20 min. RVD was correlated negatively to the extracellular osmolarity (r=-0.99, P<0.05) and positively to the swelling volume(r=0.99, P<0.05) in "S" shape, respectively. Chloride channel blockers, tamoxfen (20 micromol/ L), ATP (10 mmol/L) and NPPB (100 micromol/L), inhibited RVD by 100%, 76.3% and 62.7% (P< 0.01), respectively. The results indicated that primary-culturing fetal human nasopharyngeal epithelial cells are capable of RVD. Cl- efflux through Cl- channels is the key mechanism of RVD.

Randomised control trial of tongue acupuncture versus sham acupuncture in improving functional outcome in cerebral palsy

BACKGROUND

Traditional Chinese medicine (TCM) has been used historically in the treatment of cerebral palsy (CP). We investigated the efficacy of acupuncture in improving the motor function of children with CP.

METHODS

A randomised control trial was conducted to assess the effect of tongue acupuncture (TAC) in 33 CP children. The subjects were randomised to treatment (n = 22) with TAC or control (n = 11). Clinical outcome was evaluated using the gross motor function measure (GMFM) and the pediatric evaluation of disability inventory (PEDI).

RESULTS

The increase in mean GMFM score was significantly greater in the treatment than in the control group (p = 0.042).

CONCLUSION

An improvement in motor function of CP subjects is seen following a short course of acupuncture.

Ruthenium complexes with a terminal hydrazido ligand. Synthesis, spectroscopy, and X-ray crystal structure

Bis(1,1-diphenylhydrazido(1-))ruthenium(IV) porphyrins, [Ru(IV)(Por)(NHNPh2)2] (Por = TPP, TTP, 4-Cl-TPP, 4-MeO-TPP), were prepared in approximately 60% yields through the reaction of dioxoruthenium(VI) porphyrins, [Ru(VI)(Por)O2], with 1,1-diphenylhydrazine in ethanol. This new type of ruthenium complex has been characterized by 1H NMR, IR, UV-vis, and FABMS with elemental analysis. The crystal structure of [Ru(IV)(TTP)(NHNPh2)2], which reveals an eta1-coordination mode for both hydrazido axial ligands, has been determined. The average Ru-NHNPh2 distance and Ru-N-N angle were found to be 1.911(3) A and 141.1(3) degrees, respectively. The porphyrin ring exhibits a ruffling distortion that is unprecedentedly large for ruthenium complexes with simple porphyrinato ligands (such as TTP). This is probably due to the steric effect of the axial hydrazido(1-) ligands.

Reactivity of dioxoruthenium(VI) porphyrins toward amines. Synthesis and characterization of bis(arylamine)ruthenium(II), bis(arylamido)- and bis(diphenylamido)ruthenium(IV), and oxo(tert-butylimido)ruthenium(VI) porphyrins

Reactions of dioxoruthenium(VI) porphyrins, [Ru(VI)O2(Por)], with p-chloroaniline, trimethylamine, tert-butylamine, p-nitroaniline, and diphenylamine afforded bis(amine)ruthenium(II) porphyrins, [Ru(II)(Por)(L)2] (L-p-ClC6H4NH2, Me3N, Por=TTP, 4-Cl-TPP; L=tBuNH2, Por = TPP, 3,4,5-MeO-TPP, TTP, 4-Cl-TPP, 3,5-Cl-TPP) and bis(amido)ruthenium(IV) porphyrins, [Ru(IV)(Por)(X)2] (X=p-NO2C6H4NH, Por=TTP, 4-Cl-TPP; X = Ph2N, Por = 3,4,5-MeO-TPP, 3,5-Cl-TPP), respectively. Oxidative deprotonation of [Ru(II)(Por)(NH2-p-C6H4Cl)2] in chloroform by air generated bis(arylamido)ruthenium(IV) porphyrins, [RuIV(Por)(NH-p-C6H4Cl)2] (Por=TTP. 4-Cl-TPP). Oxidation of [RuII(Por)-(NH2tBu)2] by bromine in dichloromethane in the presence of tert-butylamine and traces of water produced oxo(imido)ruthenium(VI) porphyrins, [RuVI-O(Por)(NtBu)] (Por=TPP, 3,4,5-MeO-TPP, TTP, 4-Cl-TPP, 3,5-Cl-TPP). These new classes of ruthenium complexes were characterized by 1H NMR, IR, and UV/visible spectroscopy, mass spectrometry, and elemental analysis. The structure of [Ru(IV)(TTP)(NH-p-C6H4Cl)2 . CH2Cl2 was determined by X-ray crystallography. The Ru-N bond length and the Ru-N-C angle of the Ru-NHAr moiety are 1.956(7) A and 135.8(6) degrees, respectively.

Site of macrophage inhibition of luteinizing hormone-stimulated testosterone production by purified leydig cells

It has been observed that testicular macrophages and testicular macrophage-conditioned medium reduce LH-stimulated, but not basal, testosterone production by purified Leydig cells in vitro. In order to determine how this inhibition occurs, we have examined the effects of testicular macrophages and testicular macrophage-conditioned medium at discrete stages of the steroidogenic pathway. The lesion in steroidogenesis is located at a step beyond cAMP formation, because the addition of dibutyryl cAMP or cholera toxin did not overcome the testicular macrophage-conditioned medium inhibition of LH-stimulated steroidogenesis by Leydig cells. This effect of testicular macrophage-conditioned medium on Leydig cell testosterone production is first observed at 18 h after initiation of culture. However, subsequent additions of 22R-hydroxycholesterol, pregnenolone, dehydroepiandrosterone, or androstenedione to the Leydig cell cultures can overcome the inhibition so that, after a further 6 h of incubation, testosterone production is not significantly different from that of control Leydig cells cultured in the absence of testicular macrophage-conditioned medium. These results suggest that the block in steroidogenesis is beyond cAMP production but prior to the formation of pregnenolone, dehydroepiandrosterone, and androstenedione. Since the medium for these cultures contained lipoprotein, it is possible that the testicular macrophage-conditioned medium metabolizes the lipoprotein, making it unavailable to the Leydig cells. However, our results show that preincubation of lipoprotein with testicular macrophage-conditioned medium does not significantly alter testosterone production by the Leydig cells in the culture. It is concluded that testicular macrophage-conditioned medium affects the transport or availability of cholesterol to mitochondria prior to further steps in the steroidogenic pathway.

The effect of testicular macrophages and interleukin-1 on testosterone production by purified adult rat Leydig cells cultured under in vitro maintenance conditions

A functional interaction between testicular macrophages and Leydig cells has been suggested. The present study attempts to clarify the interaction between purified Leydig cells and macrophages from adult male rats in coculture, employing culture conditions that maintain Leydig cell steroidogenic responsiveness in vitro. Basal Leydig cell testosterone production over 24 h was not significantly affected by coculture with macrophages, but an inhibitory effect of testicular macrophages on testosterone production by Leydig cells over 24 h was observed in the presence of increasing doses of LH from 0.125 ng/ml up to a maximally stimulating dose of 8 ng/ml. A consistent inhibitory effect was observed over a range of Leydig cell-testicular macrophage coculture ratios from 0.5:1 to 4:1 in the presence of LH (8 ng/ml). A similar inhibitory effect on maximal LH-stimulated Leydig cell testosterone production over 24 h was observed when Leydig cells were cocultured with peritoneal macrophages. Conditioned medium collected from testicular or peritoneal macrophage cultured for 24 h also inhibited LH-stimulated Leydig cell testosterone production, indicating that the effect of the macrophages was mediated by a secreted product. Inhibition of LH-stimulated testosterone production was observed also when Leydig cells were cultured in the presence of testicular macrophages for 24 h before maximal LH stimulation (8 ng/ml) for a further 24 h. Human recombinant interleukin-1 alpha and interleukin-1 beta (0.5-10 U/ml) did not significantly alter basal or LH-stimulated Leydig cell testosterone production at 24, 48, or 72 h of culture. The specific binding of 125I-human CG to Leydig cells was not affected by testicular macrophage-conditioned medium. These data demonstrate that testicular and peritoneal macrophages inhibit LH-stimulated Leydig cell testosterone production in coculture through secreted factors, acting distal to the LH receptor, and provide further support for paracrine interactions between these cell types.

CT diagnosis of lacunae

Lacuna, a special small infarction in deep regions of the brain, is difficult to diagnose clinically. Of 182 stroke patients receiving CT scanning, 23 were diagnosed as having lacuna. 34 foci found on CT were distributed in the internal capsule, basal ganglia, thalamus and pons, with diameters varying from 3 to 22 mm. Combined CT and clinical findings showed that motor hemiplegia was present in 12 patients, pure sensory stroke in 1, sensory-motor stroke in 9, and the lock-in syndrome in 1.20 (87%) of the 23 patients partly or completely fulfilled the criteria for the lacuna syndrome. The detection of lacunae depends on the property of instrument, the method of scanning, and the thickness of slice. By showing some minor infarctions, CT has offered the possibility of diagnosis of lacunae.