[Surgical treatment for ipsilateral femoral neck and shaft fracture].

OBJECTIVE: To retrospectively analyze efficacy of single structure internal fixation and double structure internal fixation in the treatment of ipsilateral femoral shaft and neck fracture, and analyze their indications. METHODS: From June 2015 to December 2020, 21 patients with ipsilateral femoral shaft and femoral neck fracture were treated, including 14 males and 7 females, aged 23 to 69 years old with an average of(38.1±12.9) years old. According to different femoral shaft fracture sites, some patients were fixed with cephalomedullary implant for both femoral neck and the femoral shaft(single structure, InterTan or PFNA Ⅱ), some patients were fixed with cannulated screws for the femoral neck and a retrograde locking nail for the femoral shaft (dual structure), and postoperative function and complications were recorded during follow-up. In 10 cases of single-structure fixation, the femoral necks were all basicervical fractures, and the femoral shaft fractures were located in the proximal isthmus;11 cases were double-structure fixation, 9 cases in 11 were basal type of femoral neck, 2 cases in 11 were neck type, and the femoral shaft fractures were located in the isthmus and the distal isthmus. RESULTS: All patients were followed up for 12 to 27 months. No femoral head necrosis, deformity, delay or nonunion occurred in the patients with single-structure fixation, and no delayed union or nonunion occurred in femoral shaft fractures;At the final follow-up, Harris score of patients with single-structure fixation was 91.8±4.1, with 8 cases were excellent and 2 cases were good. The fractures of patients with dual-structure fixation achieved good union without femoral head necrosis, except 1 case of femoral shaft fracture had delayed union;At the final follow-up, Harris score of patients with dual-structure fixation was 92.4±5.9, 7 cases were excellent, 3 cases were good, and 1 case was fair. CONCLUSION: Good reduction and fixation is the key to the treatment of such fractures. Both the single-structure fixation and the dual-structure fixation are good methods, and it should be selected according to the locations of femoral shaft and femoral neck fractures. Single-structure fixation is a good choice for femoral shaft fractures located at the proximal isthmus and basal femoral neck fractures. For isthmus and distal femoral shaft fractures combined with ipsilateral femoral neck fractures, dual-structure fixation is recommended.

Harmine enhances GABAergic transmission onto basoamygdala projection neurons in mice.

Emerging evidence indicates that loss of inhibitory tone in amygdala with its subsequent overactivation contributes to the development of multiple mental disorders such as anxiety disorders and post-traumatic stress disorder (PTSD). Harmine is a member of natural ß-carboline alkaloids which can readily cross the blood brain barrier and displays significant antidepressant and anxiolytic effects in rodents. However, the underlying neurobiological mechanisms are largely unknown. Here, by using whole-cell patch clamp recordings in in vitro amygdala slices, we examined the effect of harmine on glutamatergic and GABAergic transmission onto basal amygdala (BA) projection neurons (PNs). Our results showed that harmine affected neither the amplitude nor the frequency of spontaneous and miniature excitatory postsynaptic currents (sEPSCs/mEPSCs) of PNs. By contrast, it markedly increased both the amplitude and frequency of the spontaneous inhibitory postsynaptic currents (sIPSCs). For mIPSCs, only an increase of their frequency but not amplitude was observed following harmine perfusion, suggesting that harmine might act through presynaptic mechanism. In parallel, a reduction of paired-pulse ratio of evoked IPSCs emerged in the presence of harmine. Furthermore, the intrinsic excitability of PNs was dramatically decreased upon harmine treatment. Together, our study suggests that harmine selectively potentiates the inhibitory but not excitatory transmission onto BA PNs, which may contribute to its antidepressant and anxiolytic influence.

The cytoplasmic nuclear shuttling of Beclin 1 in neurons with Alzheimer's disease-like injury.

The abnormal expression of the autophagy-related protein Beclin 1 has been implicated in Alzheimer's disease (AD) brains, whereas the precise involvement of Caspase-mediated Beclin 1 cleavage in AD neurons has not yet been fully clarified. In this study, we investigated the distribution of Beclin 1 fragments in neurons with AD-like injury. Our results demonstrated that Beclin 1 was expressed in neurons but not in astrocytes in both neuron-glia co-cultures and in cortical tissue slices. The full length and C-terminal fragments of human Beclin 1 was mainly expressed in cytoplasm, while the N-terminal fragment of Beclin 1 was predominantly localized in nucleus. Compared to amyloid-ß (Aß)42-1 treatment control, exposure of PC12 cells or cortical neurons to Aß1-42 resulted in cell injury, with the appearance of neuritic shortening, reduced nuclear diameter in PC12 cells, beading formation and fragmentation in cortical neurons. A partial nuclear translocation of Beclin 1 was detected in cells incubated with Aß1-42, which could be inhibited by the administration of pan-Caspase inhibitor or Caspase 3 specific inhibitor. Moreover, Beclin 1 mutation at 146/149 sites was resistant to Aß1-42-induced nuclear translocation. The nuclear translocation of Beclin 1 could also been detected in the brains of 12-month-old APPSwe/PS1dE9 transgenic mice. Our findings suggest that after Caspase 3-mediated Beclin 1 cleavage at 146/149 sites, the N-terminal fragments of Beclin 1 may partially translocate into nuclei in neurons subjected to AD-like injury.

Diagnostic Values of Serum Levels of Homocysteine and Uric Acid for Predicting Vascular Mild Cognitive Impairment in Patients with Cerebral Small Vessel Disease.

BACKGROUND This study aimed to investigate the diagnostic values of serum levels of Hcy and UA for predicting vascular mild cognitive impairment (VMCI) in patients with cerebral small vessel disease (SVD). MATERIAL AND METHODS We selected 172 cerebral SVD patients and divided them into a VMCI group and a non-VMCI group. Eighty-six healthy individuals without nervous system diseases were selected as the control group. Enzymatic cycling method was performed to detect serum Hcy and UA levels. Serum levels of folic acid (FOA) and vitamin B12 (VitB12) were detected by chemiluminescence immunoassay. Montreal cognitive assessment (MoCA) was applied to evaluate the cognitive function. The ROC curve was used to evaluate the diagnostic values of serum Hcy and UA levels for predicting VMCI. Logistic regression analysis was used to determine the possible risk factors. RESULTS Compared with the non-VMCI and control groups, serum FOA and VitB12 levels were lower and serum Hcy and UA levels were higher in the VMCI group. AUC values of serum Hcy and UA levels were 0.703 and 0.829, respectively. Serum Hcy and UA levels were negatively correlated with serum FOA and VitB12 levels, total MoCA score, and subscores on visuospatial ability and executive function, on language ability and on delayed recall, and they were positively correlated with serum cholesterol (CH) level. Serum Hcy and UA levels were indicated as risk factors for VMCI in cerebral SVD patients. CONCLUSIONS These results suggest that serum Hcy and UA levels may serve as predictive factors for VMCI in cerebral SVD patients.

Loss of Hippocampal Oligodendrocytes Contributes to the Deficit of Contextual Fear Learning in Adult Rats Experiencing Early Bisphenol A Exposure.

During early development, continuous exposure to environmental contaminants such as bisphenol A (BPA) is known to alter neuronal development, resulting in aberrant brain structure and predisposing individuals to developing neuropsychiatric disorders later in life. While the altered oligodendrocyte (OL) structure and function have been casually linked to the occurrence of numerous psychiatric diseases, it remains open whether early BPA exposure (EBE) also recruits OLs to mediate its toxicity in the brain. Here, we observed that EBE from birth to postnatal day 21 caused a substantial loss of hippocampal OLs in rat pups. The OL loss was enduring and manifested even when the affected pups spanned into their adulthood. In parallel, the expression of two key proteins in mature OLs, myelin basic protein (MBP), and monocarboxylate transporter 1 (MCT1) was markedly downregulated in adult hippocampus with a considerable reduction in the number of myelinated axons. By contrast, the myelination of individual axons remained intact. The altered hippocampal OLs were related to EBE-mediated disruption of estrogen receptor (ER) signaling in developing OLs and could be readily prevented by treatment with low level of ICI 182780, an ER antagonist. Importantly, the adult rats subject to EBE exhibited clear deficit in contextual fear memory, which highly correlated with OL loss and decreased MBP and MCT1 expression in hippocampus. The OL loss may thus represent an alternative route through which EBE has its adversity on the brain and contributes to the development of neuropsychiatric illness.

Delta Subunit-Containing Gamma-Aminobutyric Acid A Receptor Disinhibits Lateral Amygdala and Facilitates Fear Expression in Mice.

BACKGROUND: Maintaining gamma-aminobutyric acidergic (GABAergic) inhibition in the amygdala within a physiological range is critical for the appropriate expression of emotions such as fear and anxiety. The synaptic GABA type A receptor (GABAAR) is generally known to mediate the primary component of amygdala inhibition and prevent inappropriate expression of fear. However, little is known about the contribution of the extrasynaptic GABAAR to amygdala inhibition and fear. METHODS: By using mice expressing green fluorescent protein in interneurons (INs) and lacking the δ subunit-containing GABAAR (GABAA(δ)R), which is exclusively situated in the extrasynaptic membrane, we systematically investigated the role of GABAA(δ)R in regulating inhibition in the lateral amygdala (LA) and fear learning using the combined approaches of immunohistochemistry, electrophysiology, and behavior. RESULTS: In sharp contrast to the established role of synaptic GABAAR in mediating LA inhibition, we found that either pharmacological or physiological recruitment of GABAA(δ)R resulted in the weakening of GABAergic transmission onto projection neurons in LA while leaving the glutamatergic transmission unaltered, suggesting disinhibition by GABAA(δ)R. The disinhibition arose from IN-specific expression of GABAA(δ)R with its activation decreasing the input resistance of local INs and suppressing their activation. Genetic deletion of GABAA(δ)R attenuated its role in suppressing LA INs and disinhibiting LA. Importantly, the GABAA(δ)R facilitated long-term potentiation in sensory afferents to LA and permitted the expression of learned fear. CONCLUSIONS: Our findings suggest that GABAA(δ)R serves as a brake rather than a mediator of GABAergic inhibition in LA. The disinhibition by GABAA(δ)R may help to prevent excessive suppression of amygdala activity and thus ensure the expression of emotion.

Bisphenol A regulates the estrogen receptor alpha signaling in developing hippocampus of male rats through estrogen receptor.

Bisphenol A (BPA), one of the most common environmental endocrine disruptors, has been recognized to have wide adverse effects on the brain development and behavior. These adversities are related to its ability to bind estrogen receptor (ER) with subsequent alteration of its expression in the target areas. However, very little is known about whether BPA exposure also affects ER phosphorylation and its translocation to nucleus during postnatal development, two critical steps for its function. Here, we found that during development from postnatal day 7 (P7) to P21, the alpha subtype of ER (ERα) in the hippocampus of male rats experienced remarkable alterations in terms of its expression, phosphorylation and translocation to nucleus. Exposure to low level of BPA had bidirectional, development-dependent effects on the expression of ERα mRNA and protein, but decreased ERα phosphorylation and impaired its translocation to nucleus throughout the period investigated. Treatment with low dose of ICI 182,780 (ICI), an ER antagonist to block the binding of ER with BPA, reversed the altered ERα following BPA exposure, highlighting critical involvement of ER. Moreover, ICI treatment rescued the hippocampus-dependent behavioral deficits in the adult rats experiencing early-life BPA exposure. Overall, our results indicate that BPA interferes with the ERα signaling in the developing hippocampus in an ER-dependent manner, which may underlie its adverse behavioral and cognitive outcomes in adult animals.

Chronic stress impairs GABAergic control of amygdala through suppressing the tonic GABAA receptor currents.

BACKGROUND: Chronic stress is generally known to exacerbate the development of numerous neuropsychiatric diseases such as fear and anxiety disorders, which is at least partially due to the disinhibition of amygdala subsequent to the prolonged stress exposure. GABA receptor A (GABAAR) mediates the primary component of inhibition in brain and its activation produces two forms of inhibition: the phasic and tonic inhibition. While both of them are critically engaged in limiting the activity of amygdala, their roles in the amygdala disinhibition subsequent to chronic stress exposure are largely unknown. RESULTS: We investigated the possible alterations of phasic and tonic GABAAR currents and their roles in the amygdala disinhibition subsequent to chronic stress. We found that both chronic immobilization and unpredictable stress led to long lasting loss of tonic GABAAR currents in the projection neurons of lateral amygdala. By contrast, the phasic GABAAR currents, as measured by the spontaneous inhibitory postsynaptic currents, were virtually unaltered. The loss of tonic inhibition varied with the duration of daily stress and the total days of stress exposure. It was prevented by pretreatment with metyrapone to block corticosterone synthesis or RU 38486, a glucocorticoid receptor antagonist, suggesting the critical involvement of glucocorticoid receptor activation. Moreover, chronic treatment with corticosterone mimicked the effect of chronic stress and reduced the tonic inhibition in lateral amygdala of control mice. The loss of tonic inhibition resulted in the impaired GABAergic gating on neuronal excitability in amygdala, which was prevented by metyrapone pretreatment. CONCLUSIONS: Our study suggests that enduring loss of tonic but not phasic GABAAR currents critically contributes to the prolonged amygdala disinhibition subsequent to chronic stress. We propose that the preferential loss of tonic inhibition may account for the development of stress-related neuropsychiatric diseases.

Positive homotropic allosteric binding of silver(I) ions in multidentate azacalixpyridine macrocycles: effect on the formation and stabilization of silver nanoparticles.

We report herein the occurrence of a positive homotropic allosteric binding effect of two macrocyclic azacalixpyridines. This effect was firstly found to be crucial in the formation and stabilization of ultra-small silver nanoparticles.

Stuttering interneurons generate fast and robust inhibition onto projection neurons with low capacity of short term modulation in mouse lateral amygdala.

The stuttering interneurons (STi) represent one minor subset of interneuron population and exhibit characteristic stuttering firing upon depolarization current injection. While it has been long held that the GABAergic inhibitory transmission largely varies with the subtype identity of presynaptic interneurons, whether such a rule also applies to STi is largely unknown. Here, by paired recording of interneuron and their neighboring projection neuron in lateral amygdala, we found that relative to the fast spiking and late spiking interneurons, the STi-evoked unitary postsynaptic currents onto the projection neurons had markedly larger amplitude, shorter onset latency and faster rising and decay kinetics. The quantal content and the number of vesicles in the readily releasable pool were also larger in synapses made by STi versus other interneurons. Moreover, the short-term plasticity, as reflected by the paired pulse depression and depolarization-induced suppression of inhibition, was the least prominent in the output synapses of STi. Thus, the fast and robust inhibition together with its low capacity of short term modulation may suggest an important role for STi in preventing the overexcitation of the projection neurons and thus gating the information traffic in amygdala.

[Comparison of quasi-continuous and continuous tunable diode laser absorption spectroscopy for gas detection].

The theoretical analysis of the direct absorption spectroscopy, the continuous modulation spectroscopy and the quasi-continuous modulation spectroscopy was shown and the corresponding experiments were carried out in order to choose the adequate scheme of the laser modulation spectroscopy to satisfy different requirements of the detection. CO2 gas with different concentrations was detected under the same experimental conditions by using the three different modulation techniques with the same laser. Technical characteristics, signal features and detection limits were compared respectively. Results showed that the detection limit of the quasi-continuous modulation spectroscopy was approaching to that of the continuous modulation spectroscopy. However the linear distortion of the detection signal was obvious, because of the effects of laser energy intermittent and parasitic amplitude modulation on the line shape. Therefore the quasi-continuous modulation spectroscopy is not suitable for the pressure and flow measurements, which closely depend on the line shape. This work has provided reference for selections of the laser modulation spectroscopy.

[Multi-harmonic analysis of quasi-continuous-wave laser modulation absorption spectroscopy].

Numerous harmonic components such as multiple frequency, sum frequency and difference frequency of multiple modulation signals were found in quasi-continuous-wave (QCW) diode laser modulation absorption spectroscopy. Then, the authors analyzed these harmonic components' existence in terms of non-linear interactions of laser and gas absorption line. And the signals' characteristics were studied experimentally. The results shows that there are some sum frequency and difference frequency components that have larger amplitudes compared to the second harmonic wavelength modulation spectroscopy signal (2f-WMS) commonly used in tunable diode laser spectroscopy (TDLAS), and it may improve the detection sensitivity of QCW modulation spectroscopy.

[Observational study of ozone production efficiency at the Shangdianzi regional background station].

Ambient O3, NOx, NOy, and CO were measured at the Shangdianzi regional background station from 26 March to 9 October 2008, and VOCs samples were taken and analyzed. This paper uses the data to obtain the ozone production efficiency (OPE) at Shangdianzi and studies the relationship of OPE with NO, and VOCs. In addition, the potential impact from the dry deposition of NOx oxidation products on the calculated OPE was estimated and tentatively corrected. Based on this study, the daily OPE varied in the range of 0.2-21.1, with an average of 4.9 +/- 3.6. An overall OPE average of 4.3 +/- 1.5 can be obtained. The dependence of OPE on the NO, concentration can be described using an empirical parabolic function. If the concentration of NOx is lower than 14 x 10(-9), OPE increases with NO,; while if the concentration of NOx is higher than 14 x 10(-9), OPE decreases with NOx. The correlation analysis indicates that the concentrations of aromatics and OVOCs are positively correlated to OPE. Dry deposition of HNO3 and other NO, oxidation products may significantly impact the calculated OPE values, leading to overestimate. It is possible to correct such overestimate using the NOy/CO ratios obtained at an urban site and at Shangdianzi. However, this correction is less rigorous and the corrected OPE data remain to be validated. The uncorrected data can be viewed as the upper limit of the real OPE.

[Concentrations and acidity contributions of acetate and formate in precipitation at 14 stations of China].

To investigate the concentrations of organic acids in precipitation in China and their contributions to the total acidity of precipitation, samples were taken at 14 stations of regional representativeness in 2007 and analyzed for acetate and formate using ion chromatography. In this paper, data of acetate and formate in precipitation at 14 stations are presented, wet depositions of these organic acids are calculated, and contributions of them to the total free acidity (TFA) of precipitation are estimated. Based on the measurements, the mean concentrations of formate at different stations were in the range of 0.96-3.43 micromol/L, and those of acetate in the range of 0-5.13 micromol/L, close to the levels at remote sites in other countries and at the lower ends of concentration ranges from previous measurements in China. Comparisons indicate that the concentrations of the organic acids at remote sites are lower than those at sites in the vicinity of urban areas. The annual wet depositions of formate and acetate were estimated to be in the ranges of 0.38-4.18 mmol/(m2 x a) and 0.06-5.87 mmol/(m2 x a), respectively, with larger depositions in southern China and smaller depositions in northern China. The relative contributions of the two organic acids to the TFA of precipitation were estimated to be in the range of 0.02%-51.6%, with an overall average of 2.95%. This suggests that although acid rain in China is mainly caused by emissions of sulfur and nitrogen oxides, organic acids can significantly contribute to the acidification of precipitation in some regions and during some periods, hence need to be included in observational studies of acid rain.

[GC x GC measurements of atmospheric aromatic compounds near a busy high-speed road in Beijing].

Comprehensive two-dimensional gas chromatography (GC x GC) is a powerful instrumental tool often used to analyze complex mixtures. An optimized GC x GC method had been applied to the quantitative analysis of aromatic compounds in air samples collected near a busy high-speed road in Beijing during the 2007 National Holidays. In the resulting GC x GC chromatograms, aromatic species were resolved from other compound classes and were grouped in a manner that facilitated identification and integration, showing more information of aromatic compounds compared to traditional one-dimensional GC. Totally more than 30 aromatic species were identified and quantified. The average concentrations of monocyclic aromatic compounds ranged from 0.75 x 10(-9) to 24.64 x 10(-9) C, with toluene having the highest concentration, followed by m, p-xylene and ethylbenzene. The average concentrations of the measured polycyclic aromatic compounds ranged from 0.03 x 10(-9) to 2.28 x 10(-9) C, with naphthalene having the highest concentration, followed by 2-methyl-naphthalene and 4-methyl-1, 1'-biphenyl. The four-ring and higher polycyclic aromatic compounds were not detectable in the gaseous samples. The levels of aromatic compounds were significantly influenced by meteorological parameters. Benzene and toluene were poorly correlated with higher aromatic compounds though the latter compounds were highly correlated among each other, suggesting that both were significantly influenced by sources other than vehicle exhaust and gasoline evaporation.

[Distribution of cerebral vascular hemodynamic indexes].

OBJECTIVE: To describe the distribution of cerebral vascular hemodynamic indexes (CVHI). METHODS: A number of 25,355 age 35 and over were selected in the Northeast China by cluster sampling. CVHI were checked during baseline survey and were followed to see the occurrence of stroke. Distribution of CVHI among non-stroke population, individuals prior to the onset of stroke and patients with stroke were described. RESULTS: The CVHI accumulative score, V(mean), V(max) and V(min) were dramatically decreasing, but RV, Zcv, WV and DR were significantly increasing as age increased. V(max), RV and CP were significantly higher in males but WV was lower than that of females. The CVHI accumulative score, V(min) and RV were 95.0, 10.23 and 75.8 in non-stroke population, 51.25, 6.71 and 122.72 pre stroke group, and 55.0, 6.78 and 115.89 in patients with stroke respectively. There were significant differences among three groups after controlling of age and sex (P < 0.01). CONCLUSION: Variance of CVHI was closely related to age, and there appeared a significant abnormal of CVHI before and after stroke.

[A cohort study on cerebral vascular hemodynamics accumulative score and risks of stroke].

OBJECTIVE: To estimate relative risk (RR) of cerebral vascular hemodynamics indexes (CVHI) accumulative score as well as some other risk factors of stroke. METHODS: A cohort study was carried out in 25 355 participants aged 35 and over in Northeast of China from 1994 to 2001. In the baseline survey, exposure rates of hypertension, diabetes, family history of stroke and hypertension, etc. were collected and CVHI was examined. CVHI accumulative score was synthesized according to contribution of single index. During the 7-year following up, 228 stroke cases were identified and stroke coming on was defined as the endpoint of observation. Uni-variable and multiple variables analysis were carried out for estimating RR of CVHI and other risk factors of stroke. RESULTS: Uni-variables analysis indicated that RR (95% confidence interval, CI) of Hypertension, heart diseases, diabetes, family history of hypertension and stroke, overweight or obesity, alcohol intake, cigarette smoking and CVHI < 75 scores were 3.23 (2.48 - 4.20), 2.53 (1.92 - 3.33), 2.38 (1.55 - 3.64), 1.32 (1.02 - 1.72), 1.82 (1.37 - 2.41), 1.62 (1.25 - 2.11), 1.48 (1.07 - 2.04), 1.76 (1.34 - 2.31) and 7.30 (5.43 - 9.80) respectively. Cox regression analysis showed that CVHI below 75 points, family history of stroke, cigarette smoking, heart disease, hypertension, age and sex were the factors being selected in equation. There was a significant dosage response between the decrease of CVHI score and the increase of stroke risk. RR of stroke reached 12.55 when CVHI below 75 points and history of hypertension appeared in the same individuals. CONCLUSION: Abnormality of CVHI score seemed to be the most important and independent factor among stroke risk factors. Decrease of CVHI score might serve as a marker of high risk and play important role in stroke, especially coexistence with hypertension.