D-amino acids were believed to have no function in higher organisms several years ago. Recently, D-serine was proved to be synthesized by astrocytes in vivo and be released to work as an effective coagonist at the “glycine-binding” site of the N-methyl-D-aspartate (NMDA) glutamate receptors in central nervous system. In this paper, the synthesis, metabolism and function of D-serine were reviewed briefly.

Objective To study the effects of CBL teaching mode on treatment plan making process among orthodontic postgraduates. Methods Totally 42 junior and senior orthodontic post-graduates were randomly divided into 2 groups (21 per group)named as experimental group and test group. Each group was further divided in to 3 teams involved in CBL and traditional teaching. Six cases of the same type malocclusion were selected each time;after 4 teaching cycle,test scores of two groups were analyzed with SPSS 19.0. Results were shown as mean ± standard deviation and t test andχ2 test were applied to evaluate the rationality and accuracy of treatment plan made by students. Survey questionnaire were issued to teachers and students after class and the assessment results of CBL teaching mode were summed up. Results Test scores were (88.61±8.34)in experimental group and (76.13±8.59)in control group with significant differences (t=3.16,P=0.01). Pass rate of two groups were 96.12%and 87.51%with significant differences (χ2=4.76,P=0.02). During the first teaching program, accurate rates of experimental group and control group were respectively 31.00% and 36.70% and ra-tionality were 33.31%and 33.30%. During the second teaching program,accurate rates of experimen-tal group and control group were 68.80%and 45.70%and rationality were 62.72%and 43.37%. During the third teaching program,accurate rates of experimental group and control group were 89.70% and 51.20%,and rationality were 95.00% and 66.70%. During the fourth program,accurate rates of ex-perimental group and control group were respectively 97.80% and 55.30% and rationality were 98.30% and 75.60%. Conclusions CBL teaching mode is helpful to improve the students' ability of analyzing clinical cases and making more accurate and rational treatment plan,however the increasing teaching cost and the course load are also involved.

Objective To explore the applied value of thyroid imaging reporting and data system (TI-RADS) strati?fication in diagnosing thyroid nodules in patients with different ages.Methods A total of 527 patients with thyroid nod?ules (aged 26-65) were divided into four groups:aged 26-35 group, aged 36-45 group, aged 46-55 group and aged 56-65 group. TI-RADS was used to evaluate patients in four groups. The results of TI-RADS were compared with the pathologic di?agnostic analysis. Results For the low aged groups (aged 26-35 group and aged 36-45 group), the positive predictive val?ue, the negative predictive value and accuracy rate were more than 90%. With regard to the patients aged 46-55, the positive and negative predictive values and accuracy rate were 81.5%, 87.5%, and 81.9%, respectively. The positive and negative predictive values, accuracy rate were 76.6%,88.8%and 77.9%for patients aged 56-65 group. The diagnostic rate of TI-RADS in patients with thyroid lesions was lower in aged 56-65 group than that of other groups. Conclusion TI-RADS method is affected by age. The diagnostic rate is lower in the high age group than that of the low age group.

Objective To establish the method of contact heat evoked potential(CHEP)and to explore the value of this evoked potential in pain testing of patients with cerebral infarction.Methods A total of 100 healthy volunteers and 30 patients were examined.The healthy volunteers were divided into 3 groups according to the length of their arms:(Group A:56.0～65.0 cm ;Group B :65.5～74.0 cm ;Group C :74.5～83.0 cm).A recently de- veloped heat-foil technique with a rapid temperature rising rate at 70℃/s was used to elicit pain and contact heat e- voked potentials.Contact heat was delivered via one circular thermode(diameter 27 mm,area 573 mm~2)and set at two intensity levels(49.5℃and 54.5℃)to three body sites:the thenar eminence,the dorsum of hand and proximal volar forearm.The subjects were asked to rate the pain with numerical rating scale after each stimulus and CHEP was recorded from Cz and Pz.The association between stimulus intensities and pain rating was explored,the main compo- nents of the evuked potential were watched.CHEP,sensory conduction velocity(SCV)and somatosensory evoked potentials(SEP)were performed in patients with hemi-anesthesia caused by cerebral infarction.Results The pain intensity ratings were 3.2?0.3 and 4.4?0.5 at thenar eminence,5.0?0.7 and 6.3?0.8 at the dorsum of hand and 5.3?0.6 and 7.2?0.5 at the proximal volar forearm when the temperature of 49.5℃and 54.5℃was applied, respectively;Three components,Cz/N550,Cz/P750 and Pz/P1000,were identified in the evoked potentials.Cz/ N550 and Cz/P750 appeared when the dorsum of hand and proximal volar forearm were stimulated.In contrast,Pz/ P1000 could be identified when nociceptors of thenar eminence and proximal volar fbrearm were excited.In the pa- tients with cerebral infarction,CHEP disappeared or became abnormal on one side,while SCV and SEP were normal on that side.Conclusion It was suggested that CHEP could be elicited reliably in the controls.CHEP is helpful in the assessment of analgesia in patients with cerebral infarction.

Objective To evoke cerebral potentials by stimulating nociceptive fibers with contact heat evoked potentials stimulator (CHEPS)and estimate the nerve conduction velocities of peripheral nerve fibers mediating these responses.Methods Subjects were set in supine position.A heat-foil technology with a rapid rising speed at 70 ℃/s was used to elicit pain and contact heat evoked potentials(CHEP).Contact heat was delivered via one circular thermode (diameter 27 mm,area 573 mm~2).Thermal stimuli were sent at two intensity levels (49.5 ℃ and 54.5 ℃) to three body sites:thenar eminence,the dorsum of hand and proximal volar forarm.Contact heat evoked potentials were recorded from Cz and Pz.A systemic effect between stimulus intensities and pain rating were observed,the main components of this evoked potential were observed.Nerve conduction velocity was calculated from latency difference of CHEP and center to center distance of distal and proximal stimulus arrays.Results The pain intensity rating was 3.2?0.3 and 4.4?0.5 when thenar eminence was stimulated at the temperature of 49.5 ℃ and 54.5 ℃ respectively;the rating was 6.3?0.8 and 7.2?0.5 when the dorsum of hand and proximal volar forarm were stimulated at the temperature of 54.5 ℃ respectively.Three components,Cz/N550,Cz/P750 and Pz/P1000,were found in the evoked potentials.Nerve conduction velocities of the fibers were (12.9?7.5) and (1.7?0.4) m/s respectively,which were corresponding to those of A8 fiber and C fiber.Conclusions CHEPs can be elicited reliably and stably.Velocities of peripheral nerve fibers demonstrate that A8 fiber and C fiber mediate the response.

Blood Gas Analysis ; Continuous Positive Airway Pressure ; instrumentation ; Humans ; Infant ; Infant, Newborn ; Pneumonia ; blood ; physiopathology ; therapy ; Respiration

Objective To valuate the effect of Ro20-1724 on ketamine-induced apoptosis in hippocampal neurons of neonatal rats.Methods Hippocampal neurons from newborn Sprague-Dawley rats were obtained and cultured in vitro.The primary hippocampal neurons were randomly divided into 4 groups (n =24 each) using a random number table:control group (group C),ketamine group (group K),solvent control group (group E),and Ro20-1724 group (R group).The neurons were incubated for 72 h in the normal culture medium in group C.The neurons were incubated for 72 h in the culture medium containing ketamine 150 μmol/L in group K.In E and R groups,after the neurons were incubated for 30 min in the culture medium containing ketamine 150 μmol/L,the culture medium was then replaced,0.01％ ethanol (final concentration) and 1 × 10-3 μmol/L Ro20-1724 (final concentration) were added to the culture medium,respectively,and the neurons were then incubated for 72 h.After 72 h incubation,the cell viability was detected by MTT assay,the cell apoptosis was detected by flow cytometry,the expression of Bcl-2 mRNA and Bax mRNA was determined by RT-PCR,and synaptophysin Ⅰ expression was detected by Western blot.The apoptosis rate was calculated.Results Compared with group C,the survival rate was significantly decreased,the apoptosis rate was increased,the expression of Bcl-2 mRNA and synaptophysin Ⅰ was down-regnlated,and Bax mRNA expression was up-regulated in K and E groups (P ＜ 0.05 or 0.01).Compared with group K,the survival rate was significantly increased,the apoptosis rate was decreased,the expression of Bcl-2 mRNA and synaptophysin Ⅰ was up-regulated,and Bax mRNA expression was downregulated in R group (P ＜ 0.05 or 0.01).Conclusion Ro20-1724 can inhibit ketamine-induced apoptosis in hippocampal neurons of neonatal rats and correction of Bcl-2/Bax imbalance is involved in the mechanism.

Objective To investigate the effects of RO20-1724 on repetitive ketamine administration-induced learning and memory impairment in immature rats.Methods Forty-eight 21-day-old SD rats of both sexes weighing 45-55 g were randomly divided into 4 groups (n =12 each):control group(group C); ketamine group (group K); ketamine + RO20-1724 group (group K+ R) and ketamine + vehicle (ethanol) group (group K+ A).Ketamine 70 mg/kg was injected intraperitoneally (IP) once a day for 7 consecutive days in groups K,K+ R and K+ A.RO20-1724 0.5 mg/kg and equal volume of ethanol were injected IP at 30 min after IP ketamine once a day for 7 consecutive day in groups K + R and K + A respectively.Morris water maze test was used to assess learning and memory ability.The escape latency and the number of times of passing the safe zone were recorded.The animals were killed after water maze test and their brains removed for microscopic examination of hippocampus and determination of p-CREB protein expression in hippocampus (by Western blot).Results Repetitive ketamine administration significantly prolonged the escape latency,decreased the number of times of passing the safe zone and down-regulated the expression of p-CREB protein in hippocampus on the 3rd and 4th day in group K as compared with group C.RO20-1724 significantly attenuated the above changes induced by repetitive ketamine administration in group K + R as compared with group K.Electron microscopic examination showed that RO20-1724 significantly ameliorated repetitive ketamine administration-induced hippocampal neuronal damage.Conclusion RO20-1724 can ameliorate cognitive dysfunction induced by repetitive ketamine administration.Up-regulation of cAMP /CREB signaling pathway is involved in the mechanism.

Objective To investigate the clinical significance of brain-derived neurotrophic factor (BDNF) from peripheral serum in patients of vascular cognitive impairment (VCI).Methods Forty VCI subjects (including 10 mild cognitive impairment vascular(MCI-V) and 30 vascular dementia(VD)),and the control group for the same period in 40 healthy persons.Enzyme-linked immunosorbant assay (ELISA) was used to measure the serum levels of BDNF,statistical analysis was performed.Results The peripheral serum levels of BDNF in VCI (0.175 ±0.056) ng/L were lower than those of control group (0.211 ±0.061) ng/L,and there were significant differences (t =-2.752,P ＜ 0.05).The levels of BDNF showed no significant difference between MCI and VD ((0.195 ± 0.067) ng/L vs.(0.168 ± 0.052) ng/L,t =1.310,P ＞ 0.05).But they were both significantly lower than the control group (F =4.590,P =0.013).No significant differences were observed in the levels of BDNF between subcortical small vessel dementia (0.178 ± 0.057) ng/L and big vascular dementia (0.154 ± 0.042) ng/L (t =1.278,P =0.212).Conclusion BDNF participate in pathophysiology of VCI,and the serum levels of BDNF may be a candidate marker for clinical diagnosis of VCI.But serum levels of BDNF could not reflect the severity or the type of the VCI.

Objective To make a comparative assessment on both the therapeutic effects and side effects between percutaenous lauromacrogol injection therapy(PLIT) and percutaenous ethanol injection therapy(PEIT) for simple hepatic or renal cyst.Methods In group A,55 patients with simple hepatic or renal cysts underwent ultrasound-guided aspiration and successive PLIT.The intra-operative side effects were investigated and the therapeutic effects assessment by using ultrasonography was conducted 3 months after the treatment.In group B,60 patients with simple hepatic or renal cysts had received ultrasound-guided aspiration and PEIT sometime before.The intra-operative side effects and therapeutic effects on the thirdmonth ultrasonography were independently reviewed according to their case records.Results In group A,3 patients(5.5 ％) expressed slight discomfort but not pain while receiving lauromacrogol injection.Follow-up ultrasound examination at the end of third month demonstrated the cysts in 43 patients completely regressed,while cysts in rest 12 patients shrank over 50 ％ in size,showing the overall response rate(ORR) and completely cure rate(CCR) were 100％ (55/55) and 78.2％ (43/55) for PLIT respectively.In group B,12 patients(20％) suffered from slight to moderate irritating pain or drunk performance.The third-month ultrasound examination disclosed that cysts in 47 patients completely vanished,and cysts in the other 13patients shrank more than a half,indicating the ORR and CCR were 100％ (60/60) and 78.3 ％ (47/60) for PEIT respectively.Conclusions Although their therapeutic efficacy are perfectly similar,PLIT is much more superior to PEIT in term of less and minor side effects.