[Microbial Diversity and Community Analysis of Dental Plaques in Orthodontic Patients Wearing Invisible Appliances and Fixed Appliances].

Objective: To explore the microbial diversity and community structure of dental plaques in orthodontic patients with invisible appliances and fixed appliances and to study the differences. Methods: Ten orthodontic patients wearing invisible appliances (I) and ten wearing fixed appliances (F) were recruited. Dental plaques were collected from both buccal (B) and lingual (L) sides. Based on 16S rDNA, 40 dental plaque samples were analyzed after Illumina sequencing. Results: The microbial diversity, abundance and evenness of the FB group were significantly higher than those of the IB and IL groups (P<0.05), while the FL group showed substantial individual differences. The community structures were generally similar among the four groups, but significant differences in the relative abundance of some bacteria were found. The IB group showed higher abundances of Actinomycetes and Rosella (P<0.05), which were considered to be involved in dental caries and periodontal diseases. Some key communities showing significant differences were significantly enriched in the FB group, including Coprobacillus, Bifidobacterium, Enterobacterium, Lactobacillus, etc.. Conclusion: Dental plaques in patients wearing invisible appliances and fixed appliances showed significantly different microbial abundance, diversity and composition, which may be involved in orthodontic complications such as dental caries and periodontal diseases. Orthodontic patients need strengthened measures for oral hygiene maintenance, no matter what kind of appliances they wear.

Cerebral structural alterations in the patients undergoing postherpetic neuralgia: A VBM-MRI study.

This study aimed to investigate the changes in gray matter (GM) volume and density in patients with postherpetic neuralgia (PHN). Using voxel-based morphometry (VBM), the differences in cerebral GM volume and concentration between 25 PHN patients and 25 healthy controls with similar gender ratios, ages, and education were compared. Meanwhile, correlation analysis was performed between the value of GM volume/concentration in the brain areas with discrepancy and the visual analog scale (VAS) score/lesion duration. The global GM volume in PHN patients was lower than that of healthy controls, while the total volume of cerebrospinal fluid in PHN patients was higher than that of healthy controls. In PHN patients, the GM volume decreased in the striatum, cerebellum, precentral gyrus, middle frontal gyrus, parahippocampal gyrus, postcentral gyrus, and so forth; the GM concentration decreased in the striatum, insula, middle and posterior cingulate, and superior temporal gyrus. There was a negative correlation between GM concentration in the right parahippocampal gyrus and the VAS in patients with PHN. In PHN patients, GM volume and density in the brain regions involved in nociceptive sensation, pain perception, and integration decreased significantly. The interaction between chronic pain of PHN and alteration of the cerebral structure may contribute to the occurrence and development of PHN.

[PVT1 Promoted the Proliferation and Migration Ability of BMSCs in Glioma C6 Microenvironment].

OBJECTIVE: To investigate the changes in the proliferation and migration ability of bone marrow mesenchymal stem cells (BMSCs) after indirect co-culturing with glioma C6 cells, and to examine the role of plasmacytoma variant translocation 1 gene ( PVT1), a long non-coding RNA (lncRNA), in these changes. METHODS: After separation, cultivation and identification of BMSCs, BMSCs of good growth condition were picked out and indirectly co-cultured with glioma C6 cells in Transwell chambers. These cells are henceforth referred to as the co-culture group. Normal BMSCs cultured separately were the control group. CCK-8 and soft agar colony formation assay were used to examine the proliferation ability of the two groups of cells. Flow cytometry was used to examine the cell cycle. Wound healing assay and Transwell assay were used to explore the migration ability of the cells. Quantitative real-time PCR (qRT-PCR) was used to examine the genetic expression level of PVT1 in the two groups. The above-mentioned tests were repeated after the co-cultured BMSCs were transfected with si- PVT1 (si- PVT1 group) and si-NC (si-NC group). In addition, qRT-PCR was done to evaluate the expression of CyclinD1, a cell cycle protein gene, and matrix metalloproteinases 2 and 9 ( MMP2 and MMP9), the migration-related genes in the si- PVT1 and si-NC transfected co-cultured BMSCs. RESULTS: The BMSCs used in the present study possess the capability of osteogeneic and adipogenic differentiation. Compared with the control group, the co-cultured BMSCs had smaller size, disorderly arrangement and the lack of intercellular contact inhibition. The proliferation and migration ability was significantly enhanced, the proportions of S and G 2 phase cells greatly increased and the expression level of PVT1 was significantly up-regulated ( P<0.05) in the co-cultured group in comparison with those of the control group. When compared with the si-NC group, the si- PVT1 group showed inhibited proliferation and migration ability of the co-cultured BMSCs; the percentage of G 1 phase cells increased, while that of S phase decreased; the expression of PVT1, CyclinD1, MMP2 and MMP9 mRNA also decreased ( P<0.05) in the si- PVT1 group. CONCLUSION: The enhanced proliferation and migration ability of BMSCs in the glioma C6 microenvironment may be associated with the up-regulated expression of PVT1 .

[Study on the Expression of KDM6B of Osteoblast in Diabetic Environment].

OBJECTIVE: To investigate the ability of osteogenic differentiation and the expression of histone demethylases KDM6B in bone marrow mesenchymal stem cells (BMSCs) in diabetic environment. METHODS: Diabetic model rats was successfully established, and BMSCs from diabetic model rats and normal rats were isolated and cultured for further study. When cultured cells, we added high concentration of glucose and advanced glycosylation products (AGE) in the medium to imitating the diabetic environment. BMSCs were divided into 6 groups: diabetes group (derived from diabets SD rats), normal group (derived from normal SD rats), high glucose group (30 mmol/L D-glucose), normal glucose group (5.5 mmol/L D-glucose), AGE group (AGE 300 µg/mL) and BSA group (BSA 300 µg/mL). BMSCs in diabetes group were derived from diabetes SD rats, while others were derived from normal SD rats. After 7 d of osteogenic induction, the cells were examined the ability of osteogenic differentiation by alkaline phosphatase (ALP) staining, the transcription levels of Runt-related transcription factor 2 (Runx2) and KDM6B were determined by RT-PCR, and the expression levels of H3K27Me3 protein were examined by Western bolt. RESULTS: Compared with the control groups, the numbers of ALP stained cells and the mRNA levels of Runx2 and KDM6B in diabetes group, high glucose group and AGE group were all decreased (P < 0.05), while H3K27Me3 protein expression levels were all increased (P < 0.05). CONCLUSION: The ability of osteogenic differentiation of BMSCs in diabetic environment was weakened, and the expression of Runx2 mRNA was inhibited, which may be related to the increased expression of H3K27Me3 after the inhibition of KDM6B expression.

[Effects of Bisphosphonates on Beclin1 and LC3â ¡ Induced by High-glucose in Rat Bone Marrow Mesenchymal Stem Cells].

OBJECTIVE: To investigate the effects of bisphosphonates on autophagy induced by high-glucose in rat bone marrow mesenchymal stem cells (BMSCs). METHODS: BMSCs were isolated and cultured in vitro, identified by undergoing osteogenic/chondrogenic/adipogenic differentiation, the concentration of bisphosphonates was determined by CCK-8 method. The cells were cultured in normal glucose (5.6 mmol/L D-glucose), high glucose (30 mmol/L D-glucose), and high glucose with bisphosphonates (30 mmol/L D-glucose+10-9 mmol/L bisphosphonates). At 48 h, mRNA expression levels of autophagy related genes Beclin1 and microtubule-associated protein 1 light chain 3 (LC3) were dected by real-time PCR, protein expression levels of Beclin1 and LC3Ⅱ were detected by Western blot, and the autophagy body was observed by transmission electron microscopy (TEM). RESULTS: The results showed that BMSCs had the ability of osteogenenic, chondrogenic and adipogenic differentiation. Compared with the control group and high glucose with bisphosphonates group, the mRNA [CM(155mm]expressions of Beclin1 and LC3 and protein expressions of Beclin1 and LC3Ⅱ in the high glucose group were increased (P<0.01 or P<0.05). TEM showed that the number of autophagy body in high glucose group was higher than that in normal group and high glucose with bisphosphonates group. CONCLUSION: Bisphosphonates may play a role of down-regulating the expression of Beclin1 and LC3Ⅱ induced by high-glucose in BMSCs.

Morphologic Analysis of the Temporomandibular Joint Between Patients With Facial Asymmetry and Asymptomatic Subjects by 2D and 3D Evaluation: A Preliminary Study.

Signs and symptoms of temporomandibular joint (TMJ) dysfunction are commonly found in patients with facial asymmetry. Previous studies on the TMJ position have been limited to 2-dimensional (2D) radiographs, computed tomography (CT), or cone-beam computed tomography (CBCT). The purpose of this study was to compare the differences of TMJ position by using 2D CBCT and 3D model measurement methods. In addition, the differences of TMJ positions between patients with facial asymmetry and asymptomatic subjects were investigated. We prospectively recruited 5 patients (cases, mean age, 24.8 ±â€Š2.9 years) diagnosed with facial asymmetry and 5 asymptomatic subjects (controls, mean age, 26 ±â€Š1.2 years). The TMJ spaces, condylar and ramus angles were assessed by using 2D and 3D methods. The 3D models of mandible, maxilla, and teeth were reconstructed with the 3D image software. The variables in each group were assessed by t-test and the level of significance was 0.05. There was a significant difference in the horizontal condylar angle (HCA), coronal condylar angle (CCA), sagittal ramus angle (SRA), medial joint space (MJS), lateral joint space (LJS), superior joint space (SJS), and anterior joint space (AJS) measured in the 2D CBCT and in the 3D models (P < 0.05). The case group had significantly smaller SJS compared to the controls on both nondeviation side (P = 0.009) and deviation side (P = 0.004). In the case group, the nondeviation SRA was significantly larger than the deviation side (P = 0.009). There was no significant difference in the coronal condylar width (CCW) in either group. In addition, the anterior disc displacement (ADD) was more likely to occur on the deviated side in the case group. In conclusion, the 3D measurement method is more accurate and effective for clinicians to investigate the morphology of TMJ than the 2D method.

[Effects of Different Concentrations of Glucose on the Osteogenic Differentiation of Orofacial Bone Mesenchymal Stem Cells].

OBJECTIVES: To determine the effects of different concentrations of glucose on the proliferation and osteogenic differentiation of orofacial bonemesenchymal stem cells (OFMSCs). METHODS: OFMSCs were primarily cultured and identified in vitro to undergo osteogenic/adipogenic/chondrogenic differentiation. The cells were exposed to osteogenic medium containing different levels of glucose: 5.5,11,16.5,25,44 mmol/L. The cell activity and proliferation index were measured using a cell counting kit (CCK)-8 and flow cytometry. The alkaline phosphatase (ALP) activity of the cells was measured at the 4th and 7th day. Alizarin red staining was carried out at the 21st day. RT-PCR detecting osteogenesis-related gene Runx2 and Osterix mRNA expression was performed at the 4th, 7th, 14th and 21st day. RESULTS: Osteogenesis induced calcium nodes was observed with Alizarin red staining at the 21st day. Adipogenic induced red lipid droplets was observed with Oil Red O staining at the 14th day. Chondrogenic induced blue cytoplasm was observed with Alcian blue staining at the 14th day. With 5.5 to 25 mmol/L glucose,OFMSCs proliferation was promoted.But when the concentration of glucose continued to increase (from 25 to 44 mmol/L),OFMSCs proliferation significantly reduced.The ALP activity decreased with glucose in a concentration-dependent manner ( P<0.05). Osteogenesis induced Alizarin red staining and mineralization showed at the 21st day. The calcium nodes and mineralization quantity decreased with glucose in a concentration-dependent manner ( P<0.05).The cells exposed to 5.5 mmol/L glucose had a higher level of expression of Runx2 and Osterix mRNA than the others (P<0.05).The experssion of Runx2 and Osterix mRNA in all groups showed a trend of rising first, followed by an obvious down regulation. CONCLUSIONS: With certain limits,OFMSC proliferation is promoted by glucose. Osteogenic differentiation is inhibited by glucose in a concentration-dependent manner.

[Study on the Characteristics of Bone in Type-2 Diabetic Rats by Micro-CT].

OBJECTIVES: To study the characteristics of bone in type 2 diabetic rats using micro-CT. METHODS: Sixteen male Sprague Dawley(SD) rats, aged 8 week-old, were randomly divided into normal group and experimental group (n =10). Afer being fed with high-fat chow, the rats in experimental group were given low-dose streptozotocin (STZ,30 mg/kg) to induce type 2 diabetic disease. Serum glucose, insulin and tissue sections of pancreas is used to evaluate the effect of type 2 diabetic rat model. The characteristics of bone in the two groups were measured and compared by micro-CT. RESULTS: Compared with normal group (n =10), the experimental group (n =9) had the body mass and serum glucose increased significantly (P<0.05). The level of serum insulin was equivalent in two groups(P>0.05). Pancreatic tissue section staining showed in experimental group islet morphology was irregular, edge boundary was blur and islet cells were saperated with increasing fiber tissue. The bone volume of normal and experimental groups were (0.194 2±2.332)%, and (0.080 7±1.952)%, respectively. Trabecular thickness (unit:mm) were 0.052 9±0.004 5 and 0.043 6±0.002 4, respectively. Trabecular number (unit:mm⁻¹) were 3.668 8±0.134 5, and 1.851 7±0.288 8, respectively ( P<0.05), while trabecular space (unit:mm) were 0.219 6±0.072 1 and 0.496 5±0.076 4, respectively( P<0.05). Bone tissue morphology metrology test results was consistent with the results of micro-CT. CONCLUSIONS: The diabetic rat model showed declined bone volume and trabecular density, trabecular number. Micro-CT may be more intuitive in bone quality inspection to reflect the characteristics of bone microstructure morphology.

Differences in the mandibular premolar positions in Angle Class I subjects with different vertical facial types: A cone-beam computed tomography study.

OBJECTIVE: To compare the positions of the mandibular premolars in Angle Class I subjects according to vertical facial type. The results will provide a theoretical basis for predicting effective tooth movement in orthodontic treatment. METHODS: Cephalometric parameters were determined using cone-beam computed tomography in 120 Angle Class I subjects. Subjects were categorized as short, normal, and long face types according to the Frankfort mandibular angle. Parameters indicating the position of the mandibular right premolars and the mandible were also measured. RESULTS: The angle between the mandibular first premolar axis and buccal cortex, the distance between the root apex and buccal cortex, angle of vestibularization, arc of vestibularization, and root apex maximum movable distance were significantly greater in the short face type than in the long and norm face types. The angle between the mandibular second premolar axis and buccal cortex, the distance from root apex to buccal cortex, and the arc of vestibularization were significantly greater in the short face type than in the normal face type. CONCLUSIONS: There are significant differences in the mandibular premolar positions in Class I subjects according to vertical facial type.

The efficacy and safety of panitumumab in the treatment of patients with metastatic colorectal cancer: a meta-analysis from five randomized controlled trials.

BACKGROUND: The efficacy of adding panitumumab to chemotherapy remains controversial in the treatment of metastatic colorectal cancer (mCRC). Thus, we conducted this meta-analysis to assess the efficacy and safety of this combination regimen in patients with mCRC. METHODS: The PubMed, Embase, and Web of Science databases were comprehensively searched. Eligible studies included randomized controlled trials (RCTs) that estimated the efficacy of panitumumab with or without chemotherapy in the treatment of patients with mCRC. Hazard ratio (HR), risk ratio (RR), and 95% confidence intervals (CIs) were calculated, and heterogeneity was tested using I (2) statistics. RESULTS: Four studies involving a total of 3,066 patients were included in this meta-analysis. The addition of panitumumab to chemotherapy significantly improved progression-free survival (PFS) (HR =0.84, 95% CI =0.78-0.91, P=0.000) and the objective response rate (ORR) (RR =2.18, 95% CI =1.13-4.22, P=0.021) compared to chemotherapy alone, but no effect was noted on overall survival (OS) (HR =0.97, 95% CI =0.89-1.05, P=0.402). Subgroup analysis based on KRAS gene status revealed that the combined therapy significantly improved PFS (HR =0.71, 95% CI =0.57-0.88, P=0.002) and ORR (RR =2.43, 95% CI =1.21-4.90, P=0.013) in patients with wild-type KRAS tumors. Irinotecan-based chemotherapy plus panitumumab significantly prolonged PFS in patients with mCRC (HR =0.84, 95% CI =0.76-0.94, P=0.002). The combined treatment also increased the incidence of grade 3/4 adverse events. CONCLUSION: This meta-analysis indicates that the combination of panitumumab and chemotherapy effectively improved PFS and ORR, but it did not prolong OS. However, as the number of studies in the meta-analysis was limited, more large-scale, better-designed RCTs are needed to assess the combination of panitumumab and chemotherapy.

[Influence of healing process of extraction on related growth factors in microscrew-bone interface of implanted titanium microscrews near the extraction wounds].

OBJECTIVE: To detect the expression of growth factors relating to bone reconstructions in microscrew-bone interface of implanted titanium microscrews near the extraction wounds, and to determine the influence of healing process on the growth factors. METHODS: Eight male Beagle dogs (age 18 months) were divided into experimental and control groups. Titanium microscrews were implanted near an extraction wound in the dogs in the experimental group, while the controls had implantation without extraction wounds. The dogs were sacrificed at 1, 3, 8, 12 weeks, respectively. Immunohistochemistry and in situ hybridization sections were performed to detect the expression of TGF-beta, TNF-alpha, osteocalcin (OC) protein and Cbfal mRNA. RESULTS: The experimental group had higher levels of expression of TGF-beta, TNF-alpha protein and Cbfa1 mRNA than the controls, with significant differences appearing at week one for TNF-alpha (P<0.05), week three for TGF-beta and TNF-alpha (P<0.05), and week eight for Cbfa1 mRNA (P<0.05). The expression of OC increased over time and reached peak at week eight (P<0.05). CONCLUSION: Microscrews implanted near extraction wounds can maintain stability. Severe inflammation occurs in the early stage of healing, but does not sustain. Bone remodeling remains active over the healing process. But prolonged healing phase without force loading could weaken the remodeling.

Processing environmental stimuli in paranoid schizophrenia: recognizing facial emotions and performing executive functions.

OBJECTIVE: To study the contribution of executive function to abnormal recognition of facial expressions of emotion in schizophrenia patients. METHODS: Abnormal recognition of facial expressions of emotion was assayed according to Japanese and Caucasian facial expressions of emotion (JACFEE), Wisconsin card sorting test (WCST), positive and negative symptom scale, and Hamilton anxiety and depression scale, respectively, in 88 paranoid schizophrenia patients and 75 healthy volunteers. RESULTS: Patients scored higher on the Positive and Negative Symptom Scale and the Hamilton Anxiety and Depression Scales, displayed lower JACFEE recognition accuracies and poorer WCST performances. The JACFEE recognition accuracy of contempt and disgust was negatively correlated with the negative symptom scale score while the recognition accuracy of fear was positively with the positive symptom scale score and the recognition accuracy of surprise was negatively with the general psychopathology score in patients. Moreover, the WCST could predict the JACFEE recognition accuracy of contempt, disgust, and sadness in patients, and the perseverative errors negatively predicted the recognition accuracy of sadness in healthy volunteers. The JACFEE recognition accuracy of sadness could predict the WCST categories in paranoid schizophrenia patients. CONCLUSION: Recognition accuracy of social-/moral emotions, such as contempt, disgust and sadness is related to the executive function in paranoid schizophrenia patients, especially when regarding sadness.

[Genetic analysis and gene mapping of DDF1, a pleiotropic gene involving in both vegetable and reproductive growth in rice].

There are many pleiotropic genes playing key roles in regulating both vegetative growth and reproductive development in plants. A dwarf mutant of rice with deformed flowers, named as ddf1, was identified from indica rice breeding lines. Genetic analysis indicated that ddf1 was resulted from the recessive mutation of a single gene, temporarily named as DDF1. This result suggested that DDF1 is a pleiotropic gene, which controls both vegetative growth and reproductive development in rice. To map this gene, an F2 population was developed by crossing the ddf1 heterozygote with the tropical japonica rice variety DZ60. By means of bulked segregant analysis and small population-based linkage analysis using the published RM-series rice SSR markers, DDF1 was preliminarily mapped in a region between markers RM588 and RM587 on chromosome 6 with the genetic distances of 3.8 cM and 2.4 cM to the two markers, respectively. By developing new SSR markers in this interval according to the published rice genome sequence, we further mapped DDF1 in a 165 kb interval. The results will facilitate cloning of DDF1.

[Event-related potentials P300 with memory function and psychopathology in first-episode paranoid schizophrenia].

OBJECTIVE: To investigate the variability of event-related potentials P(300) and the relationship with memory function/psychopathology in patients with first-episode paranoid schizophrenia. METHODS: Thirty patients with first-episode paranoid schizophrenia (patient group) and twenty health subjects (control group) were enrolled in the study. The auditory event-related potentials P300 at the scalp electrodes Cz, Pz and Wechsler Memory Scale (WMS) were examined in both groups, Positive And Negative Syndrome Scale (PANSS) was evaluated in patient group. RESULTS: In comparison with control group, patients had longer latency of P300 [(390.6 ± 47.6)ms at Cz and (393.3 ± 50.1)ms at Pz] (P<0.01), lower amplitude of P300 [(7.7 ± 3.4) µV at Cz and (8.5 ± 3.9)µV at Pz] (P<0.05-0.01). The memory quotient (88.1 ± 10.0) scores and short-term memory, immediate memory in patient group were damaged significantly (P<0.05-0.01). In patient group, the latency of P300 was correlated positively with PANSS scores and negatively with WMS scores (P<0.05-0.01). CONCLUSION: First-episode paranoid schizophrenia has memory deficit, which can be evaluated comprehensively by P300 and WMS. The longer latency of P300 might be associated with the increased severity of first-episode paranoid schizophrenia.

[Histological study of miniscrew implanted in lower mandibles of juvenile and adult Beagle dogs].

OBJECTIVE: To examine the histological discrepancies between juvenile and adult Beagle dogs at different concrescence times after miniscrew implants. METHODS: Miniscrew implants were performed in six juvenile Beagle dogs and six adult Beagle dogs. The space between the fourth premolar root and first molar root, and the spaces in distal and mesial of M1 root were picked up for the implants of the 48 miniscrews. The lower jaw specimens including the miniscrews were harvested 3 and 12 weeks after the implants for the histological examinations and bone implant contact (BIC) calculations. RESULTS: There was no miniscrew falling off or becoming loose. The miniscrews had favorable biological consistencies with the tissues around them. The osteoblasts and osteoclasts showed active functions in the peri-bones of the minisrews. The BIC became higher when the healing time was prolonged. The juvenile Beagle dogs had lower BIC than the adults 3 weeks after the implants. But the BIC of the juvenile dogs surpassed the adults 12 weeks after the implants. CONCLUSION: The osseointegration of the miniscrews is hindered by the poorer bone quality of the juvenile Beagle dogs. But the early osseointegration deficiency can be made up by the rapid development and growth of the bones of the juvenile dogs.

EEG coherence characteristics at rest and during a three-level working memory task in normal aging and mild cognitive impairment.

BACKGROUND: The aim was to examine and compare the characteristics of intra- and inter-hemispheric EEG coherence in patients with mild cognitive impairment (MCI) and healthy controls at rest and during a working memory (WM) task having three levels. MATERIAL/METHODS: The subjects included 35 patients with MCI according to the DSM-IV criteria (mean age: 62.3+/-6.5 years) and 34 healthy controls (mean age: 57.4+/-4.0) selected from the community. All the subjects performed a simple calculation and recall task of WM with three levels of (WM1-3) while their EEG signal was recording. Inter- and intra-hemispheric EEG coherence was analyzed during the WM loads. RESULTS: Intra- and inter-hemispheric coherence during the WM task showed a "drop-to-rise" tendency compared with that at-rest condition. There was significantly higher coherence in MCI patients than in controls during the WM task. Intra-hemispheric ortical connectivity diminished while inter-hemispheric connectivity dominated in the MCI patients during WM with increasing task difficulty. CONCLUSIONS: MCI patients and normal controls may have differences in cortical connection and MCI patients have a cortical connection disturbance during WM tasks. With increasing task difficulty the MCI patients mobilized more inter-hemispheric than intra-hemispheric cognitive resources.

[Establishment of malodor model and its effects on identifying the halitosis-related bacteria].

OBJECTIVE: To establish a salivary sediment malodor system, and to evaluate the effect of several kinds of bacteria dedicated to the halitosis formation, hence to identify halitosis-correlated bacteria. METHODS: The proportion of the supernatant and sediment, gained from centrifugal whole saliva, was adjusted to establish a salivary sediment malodor system incubated in facultative aerobic environment under 37 degrees C for 7 hours. The halitosis indexes in both gaseous phase and liquid phase were checked by direct sniffing, and volatile sulphur compounds (VSCs) and pH were determined by halimeter and glass electrode respectively between hours to evaluate the malodor formation. The suspended fluid of suspicious halitosis-correlated bacteria and non-halitosis-correlated bacteria and water control were introduced into the salivary sediment system incubated for 1 hour. The five groups were incubated in facultative aerobic environment under 37 degrees C in the residual hours. The halitosis indexes, VSCs and pH changes were recorded between hours. RESULTS: The salivary sediment malodor system can simulate the metabolism of halitosis formation to produce halitosis. The odors of the suspicious halitosis-correlated bacteria introduced groups were higher than the non-halitosis-correlated bacteria and water control group. CONCLUSION: With its simple but fundamental manipulations, incubated whole saliva is a powerful model for study of the metabolism of the oral mixed microbial flora, malodor formation, and other oral diseases-related processes.

Alpha spectral power and coherence in the patients with mild cognitive impairment during a three-level working memory task.

OBJECTIVE: The functional relationship between calculated alpha band spectral power and inter-/intra-hemispheric coherence during a three-level working memory task of patients with mild cognitive impairment (MCI) was investigated. METHODS: Subjects included 35 MCI patients according to the DSM-IV criteria (mean age: 62.3, SD: 6.5) and 34 healthy controls (mean age: 57.4, SD: 4.0) were selected from the community at large. All subjects performed a simple calculation and recall task with three levels of working memory load while electroencephalograph (EEG) signal was recorded. The spectral EEG power was computed over alpha1 (8.0-10.0 Hz) and alpha2 (10.5-13.0 Hz) frequency bands and was compared between rest stage and working memory processing stage by two-way ANOVA. Post hoc testing analyzed the differences between each two levels of working memory load during task processing. The inter-hemisphere EEG coherence of frontal (F3-F4), central (C3-C4), parietal (P3-P4), temporal (T5-T6) as well as occipital (O1-O2) was compared between MCI patients and normal controls. The EEG signals from F3-C3, F4-C4, C3-P3, C4-P4, P3-O1, P4-O2, T5-C3, T6-C4, T5-P3 and T6-P4 electrode pairs resulted from the intra-hemispheric action for alpha1 and alpha2 frequency bands. RESULT: There was significantly higher EEG power from MCI patients than from normal controls both at rest and during working memory processing. Significant differences existed between rest condition and three-level working memory tasks (P<0.001). The inter- and intra-hemispheric coherence during working memory tasks showed a "drop to rise" tendency compared to that at rest condition. There was significantly higher coherence in MCI patients than in the controls. When task difficulties increased, the cortical connectivity of intra-hemispheric diminished while the inter-hemispheric connectivity dominantly maintained the cognitive processing in MCI patients. CONCLUSION: The results of the present study indicate that the alpha frequency band may be the characteristic band in distinguishing MCI patients from normal controls during working memory tasks. MCI patients exhibit greater inter-hemispheric connectivity than intra-hemispheric connectivity when memory demands increase. MCI patients mobilize a compensatory mechanism to maintain the processing effectiveness while the processing efficiency is reduced.

Inter- and intra-hemispheric EEG coherence in patients with mild cognitive impairment at rest and during working memory task.

OBJECTIVE: To assess functional relationship by calculating inter- and intra-hemispheric electroencephalography (EEG) coherence at rest and during a working memory task of patients with mild cognitive impairment (MCI). METHODS: The sample consisted of 69 subjects: 35 patients (n=17 males, n=18 females; 52-71 years old) and 34 normal controls (n=17 males, n=17 females; 51~63 years old). Mini-mental state examination (MMSE) of two groups revealed that the scores of MCI patients did not differ significantly from those of normal controls (P>0.05). In EEG recording, subjects were performed at rest and during working memory task. EEG signals from F3-F4, C3-C4, P3-P4, T5-T6 and O1-O2 electrode pairs are resulted from the inter-hemispheric action, and EEG signals from F3-C3, F4-C4, C3-P3, C4-P4, P3-O1, P4-O2, T5-C3, T6-C4, T5-P3 and T6-P4 electrode pairs are resulted from the intra-hemispheric action for delta (1.0-3.5 Hz), theta (4.0-7.5 Hz), alpha-1 (8.0-10.0 Hz), alpha-2 (10.5-13.0 Hz), beta-1 (13.5-18.0 Hz) and beta-2 (18.5-30.0 Hz) frequency bands. The influence of inter- and intra-hemispheric coherence on EEG activity with eyes closed was examined using fast Fourier transformation from the 16 sampled channels. RESULTS: During working memory tasks, the inter- and intra-hemispheric EEG coherences in all bands were significantly higher in the MCI group in comparison with those in the control group (P<0.05). However, there was no significant difference in inter- and intra-hemispheric EEG coherences between two groups at rest. CONCLUSION: Experimental results comprise evidence that MCI patients have higher degree of functional connectivity between hemispheres and in hemispheres during working condition. It suggests that MCI may be associated with compensatory processes during working memory tasks between hemispheres and in hemispheres. Moreover, failure of normal cortical connections may exist in MCI patients.

Hemodynamic changes in depressive patients.

OBJECTIVE: This study is aimed at exploring the relationship between hemodynamic changes and depressive and anxious symptom in depression patients. METHODS: The cardiac function indices including the left stroke index (LSI), ejection fraction (EF), heart rate (HR), diastolic pressure mean (DPM), systolic pressure mean (SPM), left ventricle end-diastolic volume (LVDV), effective circulating volume (ECV), resistance total mean (RTM) and blood flow smooth degree (BFSD) were determined in 65 patients with major depressive disorders and 31 healthy normal controls. The clinical symptoms were assessed with Hamilton depression scale (HAMD) and Hamilton anxiety scale (HAMA). RESULTS: In patients with depression without anxiety, LSI, EF, LVDV, DPM, SPM, ECV, BFSD were significantly lower than those in controls, while RTM was higher than that in controls. Patients with comorbidity of depression and anxiety showed decreased LVDV, ECV, BFSD, and increased HR in comparison with the controls. The anxiety/somatization factor score positively correlated with LSI, EF, LVDV, but negatively correlated with RTM. There was negative correlation between retardation factor score and DPM, SPM, LVDV. CONCLUSION: The study indicated that there are noticeable changes in left ventricle preload and afterload, blood pressure, peripheral resistance, and microcirculation in depressive patients, and that the accompanying anxiety makes the changes more complicated.