BACKGROUND:The electrical impedance tomography (EIT) is a kind of examination that is used to non-invasively measure the change and distribution of electrical bio-impedance by reconstructing the frequency response obtained by electrical stimuli applied onto the human body. The characteristics of impedance of any tissues are of great importance to the imaging of EIT and locating and monitoring the lesion focus.OBJECTIVE: To measure the human brain impedance in the frequency range from 0.1 Hz to 1 MHz and to compare these with those of other human tissues and the rabbit brain tissues.DESIGN: An observational experiment.SETTING:The Department of Medical Electric Engineering of the Biomedical Engineering College of the Fourth Military Medical University of Chinese PLA.MATERIALS:The experiment was conducted at the Otolaryngology Laboratory, Department of Medical Electric Engineering of Biomedical Engineering College, Fourth Military Medical University of Chinese PLA from April, 2000 to June, 2000. Two brains were harvested from two cadavers of adult men who died in less than 12 hours before the brains were taken.INTERVENTIONS :The brains were divided into 15 samples and the Solartron 1255B frequency resoonse analyzer was used to measure the complex impedance of human brain in vitro with four-electrode measurement method in the frequency range from 0.1 Hz to 1 MHz.There were also impedance interface (1294)and self-made experimental measurement box.MAIN OUTCOME MEASURES:The resistivity frequency response,curves of real part and imaginary part of complex impedance as well as the equivalent circuit model of the complex impedance.RESULTS:The resistivity of human brain tissues was about 1 200 Ω·cm in the frequency range of 0.1-100 Hz.But it decreased to 650 Ω·cm in the frequency range of 100-1×106 Hz. The real part of complex impedance remained steady in the frequency range of 0.1-100 Hz and it decreased along with the increase of frequency in the range of 100-1×106 Hz. The absolute value of frequency response curves of the imaginary part of human brain's complex impedance presented a tendency of monotonic increase.CONCLUSION: The resistivity and the real part of complex impedance curve of human brain were in accordance with those of other tissues such as muscles, the liver, kidney and lungs. The frequency response curve of the imaginary part of human brain's complex impedance was different from that of other animal tissues (such as muscles, the liver and kidney) but was in accordance with that of rabbit brain tissues in vitro. The construction of the equivalent circuit model obtained was more complex than other models known.

A 48-year-old female presented with a one-week history of painful and enlarged lymph nodes in the left neck.One-week systemic treatment with antibiotics resulted in no obvious improvement.Skin examination revealed palpable lymph nodes between the left lateral cervical papillae and clavicle,which appeared as a string of beads with a little mobility and obvious tenderness.The largest diameter of enlarged lymph nodes was about 2 cm.No enlarged lymph nodes were palpable in the other body sites.Histopathologically,histiocytes of various shapes,immunoblasts and plasmacytoid monocytes markedly proliferated with different degrees of karyorrhexis.Immunohistochemistry revealed that the lesions were positive for CD3,CDS,CD68,mouse macrophage inflammatory protein,and CD20.A diagnosis of histiocytic necrotizing lymphadenitis was made.

The paper introduced the recent development of optical tweezers array.The particle manipulation system could be set up based on several methods,such as acousto-optics deflectors(AOD),diffractive optical elements(DOE),spatial light modulators(SLM),interference technique,vertical cavity surface emitting laser(VCSEL),optical fibers and micro-lens arrays as well.The principle,specification and basic structure of each method were introduced and analyzed briefly.Taking the advantage of particle trapping,optical tweezers array was very useful for manipulation of micron size particles,such as cells.Combining with microfluidics and MEMs fabrication,optical tweezer array,the ultraminiature and portable particle sorting system,would be a good choice for space biological research.

Objective To determine the origin of cord serum leptin and its relationship with neonatal anthropometry. Methods Sixty five women and their babies took part in this prospective cohort study. Blood was taken from the women just before delivery and from the umbilical cord of their babies at delivery. Serum leptin was measured by radio immunoassay. Neonatal anthropometric measurements were recorded within 48 hours after delivery. Linear regression analysis was used to explore the relationship between serum leptin concentrations and anthropometric measures and multiple regression analysis then applied to determine which variables remained independently associated with leptin. Results The leptin concentration ( ?s )in maternal serum was (19.93?7.21) ng/mL and in cord blood was (10.50?3.45) ng/mL. Cord leptin levels correlated with placental weight, neonatal birthweight, skinfold thickness and ponderal index but not with maternal leptin levels. The correlation with Placental weight and neonatal birthweight remained significant after multiple regression analysis. Conclusions Relatively big serum leptin concentration gradient between mother and umbilical vessels indicates that placenta might play an important role in leptin production. We hypothesize that leptin might play an important role during pregnancy and fetal development.

Objective Study the effect of NMDA receptor antagonist GAPA on the [Ca 2+ ]i of the bilirubin precipitated brain tissue. Methods 10 ug/g of GAPA was administrated peritoneally to Gunn rat with bilirubin induced encephalopathy, brain tissue suspensions was prepared, Fura 2/AM was loaded. the neural cytosolic Ca 2+ was measured by flurescence imaging analysis. Results The concentration of neural cytosolic Ca 2+ in bilirubin precipitated brain tissue was significantly more than that in the control group; NMDA receptor antagonist GAPA could significantly decrease the cytosolic Ca 2+ overload. Conclusion Cytosolic Ca 2+ overload was found in the bilirubin precipitated brain tissue. NMDA receptor antagonist GAPA could prevent the cytosolic Ca 2+ overload in bilirubin induced brain tissue.

Objective To study the role of placental leptin in intrauterine cord leptin production and its relationship with neonatal anthropometry. Methods Forty women and their babies were enrolled in this study. Placental tissue was obtained from mothers and assayed for leptin mRNA by reverse transcription/polymerase chain reaction (RT/PCR). Blood was taken from the umbilical cord of the babies at delivery. Serum leptin was measured by radio-immunoassay. Neonatal anthropometric measurements were recorded within 48 hours after delivery. Linear regression analysis was used to explore the relationship between placental leptin mRNA, serum leptin concentrations and anthropometric measures. Results Placental tissue expressed leptin mRNA at comparable or greater levels than adipose tissue. The placenta of the small for gestational age (SGA) neonates expressed leptin mRNA at significantly lower levels than that of the appropriate for gestational age (AGA) neonates (P=0.042), while the placenta of the large for gestational age (LGA) neonates expressed leptin mRNA at significantly higher levels than that of the AGA neonates (P=0.03). Placental leptin mRNA expression levels correlated with leptin concentrations in cord blood (r=0.61), newborn birth weight (r=0.60) and Ponderal Index (r=0.56). Conclusions Placenta provides a source of leptin for the growing fetus, and this placental leptin might be a growth factor in intrauterine fetal development.

The association of spontaneous intracranial hypotension with cerebral venous sinus thrombosis is rare. We report here a case of extensive cerebral venous sinus thrombosis involving three sinuses following spontaneous intracranial hypotension. The patient presented no other thrombotic risk factors except for spontaneous intracranial hypotension. This case adds to the evidence that spontaneous intracranial hypotension is a risk factor for cerebral venous sinus thrombosis.

Objective To investigate the risk factors related to persistent unconsciousness in patients with severe traumatic brain injury (sTBI) by way of building a prognosis model.Methods The clinical data of 165 sTBI patients admitted from July 2011 to November 2013 were retrospectively analyzed.The eligible patients were randomly assigned to derivation cohort (n =115) and verification cohort (n =50) by treatment order.Inclusion criteria:(1) age ＞ 15 years; (2) definitive history of head injury; (3) traumatic brain injury confirmed by head computerized tomography or brain MRI; (4) initial Glasgow coma score (GCS) was less than 8; (5) patient's light come or consciousness impairment gradually deteriorating to profound coma on the day of admission.The exclusion criteria were as follows:(1) only a brief loss of consciousness or coma after trauma (coma time ＜ 6 hours) ; (2) post-injury hysteria or dementia causes appearance like coma ; (3) unconsciousness results of status epilepticus which was induced by emotion after injury.Univariate and muhivariable logistic regression were employed to determine the independent predictors of persistent unconsciousness in the derivation cohort,and then prognosis model was established.The Hosmer-Lemeshow goodness-of-fit test and the area under the receiver operating characteristic curve were used to assess the capacity of model for discrimination and calibration.Results Logistic regression analysis was used to identify GCS score,neurological complications,diffuse axonal injury (DAI),electrolytes disturbance as the most important predictors of persistent unconsciousness.The model was well calibrated in the derivation cohort (Hosmer-Lemeshow test,x2 =4.380,P =0.496).The model showed good discrimination (area under the receiver operating characteristic curve) in the derivation cohort (0.87; 95％ CI:0.798-0.942) and in the versification cohort (0.90; 95％ CI:0.803-0.997).Conclusions The prognosis model could accurately predict the persistent unconsciousness lasting in sTBI patients despite its certain limitations,and therefore,it has significantly clinical and societal value.

ObjectiveTo monitor the treatment effect of acute leukemia by multiparmeter flow cytomtry(MPFC), MethodsThe patientswith acute leukemia all achieved complete remission after remission induction therapy.Before the chemotherapy,the bone marrow cell morphology and MPFC inspection were used for each patient. Through statistical analysis, the relationship between morphological feature andrecurrence,as well as time duration till recurrence were obersved. ResultsThe 122 specimens from 30 patients were observed.The specimens were analyzed by morphological examination of bone marrow cells,and the other 61 specimen through MPFC. There were 8 positive specimen(13.11％)through morphological examination,while 18 positive specimen(29.51％ )through MPFC. There was a significant difference between the two groupes by x2 test (x2=4.33,P＜0.05).The 18 MPFC-positive specimens were from 10 patients.In the follow-up period, there were 6 patients whose morphological examination also prompted the recurrence in 1-4 months. Three patients were failed to follow up because of 2 patients became negative and 1 patient died. ConclusionMPFC is more sensitive and able to assess the effect of acute leukemia treatment more objectively and detect the recurrence earlier than morphological examination.

Sequences analysis revealed Grass carp reovirus (GCRV) s10 was 909 nucleotides coding a 34 kDa protein denoted as VP7, which was determined to be a viral outer capsid protein (OCP). To obtain expressed OCP in vitro, a full length VP7 gene was produced by RT-PCR amplification, and the amplified fragment was cloned into T7 promoted prokaryotic expression vector pRSET. The recombinant plasmid,which was named as pR/GCRV-VP7,was then transformed into E.coli BL21 host cells. The data indicated that the expressed recombinant was in frame with the N-terminal fusion peptide. The over-expressed fusion protein was produced by inducing with IPTG, and its molecular weight was about 37kDa, which was consistent with its predicted size. In addition, the fusion protein was produced in the form of the inclusion body with their yield remaining steady at more than 60% of total bacterial protein. Moreover,the expressed protein was able to bind immunologically to anti-his-tag monoclonal antibody (mouse) and anti-GCRV serum (rabbit). This work provides a research basis for further structure and function studies of GCRV during entry into cells.