There are some problems in the teaching of medical physics course,such as low learning initiative,deficient grasp of concept,and obstacles to realize the internalization and practical application of knowledge.The PAD (presentation-assimilation-discussion) class is applied in the course,in order to improve the students' learning state.PAD class is a teaching mode proposed from a psychological point,which advocates that teaching is the first before students start to learn and has an equal treatment on students' discussions and teachers' instruction,supporting independent learning.The teaching measures include:selecting course content to reach the balance between simplification and detailed interpretation;assigning open homework based on the course;dividing the class discussion into four steps;assessing students based on the performances of homework and final examinations.The research has shown that the PAD class facilitates improving the students' initiative of study and promoting the absorption and application of knowledge.

The purpose of our present work was to study the discharge of bursting-firing neurons (BFNs) in ipsilateral or contralateral hippocampus (HPC), and its relations to the reestablishment of local epileptic networks. The experiments were performed on 140 Sprague Dawley male rats (150-250 g). Acute tetanization (60 Hz, 2 s, 0.4 -0.6 mA) of the right posterior dorsal hippocampus (ATPDH) was administered to establish rat epilepsy model. The single unit discharges and the depth electrographs were simultaneously recorded from ipsilateral or contralateral HPC. In other experimental rats, acute tetanization of the right anterior dorsal HPC (ATADH) was used. Extracellular unit discharges in the CA1 region were simultaneously recorded from bilateral anterior dorsal hippocampi. Analysis of hippocampal BFN firing patterns before or after administration of the tetanization was focused on according to their location in the HPC epileptic networks in vivo. Single unit discharges of 138 hippocampal neurons were recorded from ipsilateral and/or contralateral anterior dorsal HPC. Of the 138 neurons recorded, 19 were BFNs. 13 BFNs were tetanus-evoked and the remaining 6 were spontaneous ones. The evoked reactions of the single hippocampal neuron induced by the tetanization mainly included: (1) the firing patterns of the BFNs in ipsilateral anterior dorsal HPC were obviously modulated by the ATPDH from tonic firing into rhythmic bursting. The bursting interspike intervals (BISI) decreased. (2) There were mild modulations of the firing patterns of the BFNs in contralateral anterior dorsal HPC following post-inhibition of the firing rate of single neuron induced by the ATPDH. The interspike intervals (ISI) increased obviously. (3) Post-facilitation of rhythmic bursting-firing of the BFNs in contralateral anterior dorsal HPC was induced by ATADH; both the ISI and the IBI increased. (4) Synchronous or asynchronous rhythmic bursting-firing of the BFNs and the network epileptiform events ipsilateral or contralateral anterior dorsal HPC were elicited by the ATPDH. The results obtained suggest that bursting-firing of single BFNs is produced by the ATPDH in the anterior dorsal HPC along the longitudinal axis of the ipsilateral HPC or across the hemisphere to the opposite HPC. Rhythmic activities of the BFN may be implicated in the epileptic network reestablishment of the HPC. On the other hand, synaptic modulation of the BFN temporal series might be responsible for pathophysiological information transmission in the HPC-epileptic network.
Animals ; Electric Stimulation ; Electrophysiology ; Epilepsy, Temporal Lobe ; physiopathology ; Evoked Potentials ; Hippocampus ; physiopathology ; Male ; Nerve Net ; physiopathology ; Neurons ; physiology ; Rats ; Rats, Sprague-Dawley ; Synaptic Transmission

AIMTo investigate the neural network and cellular mechanisms of hippocampal epileptogenesis contralateral or ipsilateral to the side of acute tetanization (60 Hz, 2 s, 0.4 - 0.6 mA) of the posterior dorsal hippocampus (ATPDH).

METHODS10 trains of the ATPDH were administered into the CA1 basal dendritic region of the right hemisphere at an interval of 10 minutes.

RESULTS(1) The firing rate of CA1 single neuron in the right or the left hippocampus was inhibited respectively after the ATPDH, and the effects weakened gradually while the trains of the ATPDH increased. The inhibited firing rate and the transformed firing pattern from tonic one to clonic one were more obvious at the side contralateral to the stimulation (62.94% +/- 3.68%, 36.61% +/- 3.14%, P < 0.01). (2) Synchronous primary afterdischarges of depth EEG and single unit discharges were more commonly observed at the side ipsilateral to the ATPDH (P < 0.01). (3) Primary or secondary hippocampal network afterdischarges at high frequency were only found in CA1 region ipsilateral to the ATPDH. (4) Secondary afterdischarges of CA3 basal dendritic neural network were completely synchronized with those of subicular single neuron, which reoccurred and persisted several hours.

CONCLUSIONIt is possible that post-inhibition bursting of single neuron and recurrent network seizures in the hippocampus contralateral to the artificial focus be the important manifestation of the formation of "epileptic networks" across from one hemisphere to another.

Animals ; Electric Stimulation ; Hippocampus ; physiology ; Male ; Neural Pathways ; physiology ; Rats ; Rats, Sprague-Dawley ; Seizures ; etiology

OBJECTIVETo evaluate the advantages, disadvantages and their indications of total nasal reconstruction with different techniques.

METHODSA series of total nasal reconstruction were treated with four methods from 1975 to 2003. These methods were tubed flap of arm,midline forehead flap with skin graft, midline forehead flap with bilateral frontotemporal flaps for repairing the donor site, and expanded forehead flap.

RESULTSAll of the patients were treated successfully. The shape and function of the reconstructed noses were satisfactory. However, the traditional forehead flap with skin graft may leave a unsightly big and black scar on the forehead. The technique of the tubed flap of arm could provide enough tissue without remaining forehead scar and be easily shaped, but it required long period, multiple procedures and body fixation for three weeks.

CONCLUSIONSMidline forehead flap with bilateral frontotemporal flaps for repairing the donor site may be good for small nose reconstruction while expanded forehead flap could reconstruct a big nose. Tubed flap of arm may be used to the patients who do not wish to leave any scar on the forehead. Forehead flap with skin graft to repair the donor sit- should generally be avoided for nose reconstruction.

Adolescent ; Adult ; Female ; Humans ; Male ; Middle Aged ; Nose ; surgery ; transplantation ; Nose Deformities, Acquired ; surgery ; Reconstructive Surgical Procedures ; methods ; Reproducibility of Results ; Retrospective Studies ; Skin Transplantation ; methods ; Surgical Flaps ; Treatment Outcome

OBJECTIVETo study the biological effects of 585 nm pulsed dye laser (FLPDL) in the treatment of congestive scar.

METHODSBy histological study, collagen VG staining and microvascular staining, we investigated the changes of collagen fibers and the density of microvessels in the congestive scars after FLPDL treatment.

RESULTSHistological and immunohistochemistry examinations showed that FLPDL achieved normal vascularity in the scar after over 3 times of treatment.

CONCLUSIONSPDL treatment can change fundamentally the physiology of wound healing if applied in the early phases.

Adolescent ; Adult ; Cicatrix ; therapy ; Female ; Humans ; Lasers, Dye ; Low-Level Light Therapy ; methods ; Male ; Middle Aged ; Reconstructive Surgical Procedures ; methods ; Treatment Outcome ; Wound Healing ; Young Adult

Objective To analyze the demographic characteristics and the death causes of the residents in Anhui province,and provide evidence for the disease prevention and control.Methods Using descriptive epidemiological analysis,the demographic characteristics and death data of the national disease surveillance points (DSPs) in Anhui province in 2013 were analyed by areas.Results The aging of the population was observed in all the areas in Anhui,which was most obvious in Jianghuai,followed by Wannan and Huaibei.The overall mortality was 627.10/100 000.The mortalities of diseases varied with sex,area and age.Among the 3 areas,the overall mortality,chronic disease mortality and injury mortality were highest in Huaibei and lowest in Wannan.The area specific difference in mortality of infectious diseases was small.Regardless of areas or the types of diseases,the mortality was higher in males than in females.Deaths caused by diseases with unknown origins were common in residents aged ＞ 65 years.The mortality of chronic diseases was higher in residents aged ＞45 years,especially in those aged 65-84 years.The mortality of injuries was higher in age groups ＞15 years and ＞45 years.The mortality of infectious diseases peaked at both young age group and old age group.The top five death causes were cerebrovascular diseases,malignant tumors,heart diseases,respiratory diseases and injuries.Regardless of sex or area,the major death causes were similar,but the ranks were slightly different.The major death causes varied in different age groups,but they were similar in same age group in different areas.The major death causes were diseases originated in perinatal period,and congenital malformations,deformations and chromosomal abnormalities in children aged ＜ 1 year.The major death causes in children aged 1-14 years were injuries,diseases originated in perinatal period,congenital malformations,deformations and chromosomal abnormalities.Injuries and malignant tumors were the first and second death causes in residents aged 15-44 years.Malignant tumors,injuries,cerebrovascular diseases and heart diseases were the major death causes in residents aged 45-64 years.The major death causes were cerebrovascular diseases,malignant tumors,heart diseases and respiratory diseases in residents aged 65-84 years and heart diseases,cerebrovascular diseases,respiratory diseases and malign tumors in residents aged ≥85 years.Conclusion The major death causes in residents in Anhui province were cerebrovascular diseases,malignant tumors and injuries.Close attention should be paid to the prevention and control of cerebrovascular diseases,malignant tumors and heart diseases in age group ≥45 years.It is necessary to strengthen the prevention and control of injuries in age group 15-44 years.Huaibei is a key area of disease prevention and control in Anhui,especially chronic disease and injury preventions.

OBJECTIVETo investigate the dynamic changes of neurofilaments (NFs) proteins in spinal cords of hens with phenylmethylsulfonyl fluoride (PMSF) pretreatment for exploring the mechanism of tri-o-cresyl phosphate (TOCP)-induced delayed neuropathy (OPIDN).

METHODAdult Roman hens were randomly divided into three groups, control, TOCP and PMSF + TOCP. Birds in PMSF + TOCP set were pretreated with PMSF, 24 hours later, hens in both TOCP group and PMSF + TOCP group were administrated with TOCP at a single dosage of 750 mg/kg. Then all animals were sacrificed on the corresponding time-points of 1, 5, 10, and 21 days respectively after dosing of 750 mg/kg TOCP. The spinal cords were dissected, homogenized, and centrifuged at 100,000 x g. The levels of high molecular neurofilament (NF-H), medium molecular neurofilament (NF-M) and low molecular neurofilament (NF-L) in both pellet and supernatant fractions of spinal cords were determined by SDS-PAGE and Western-blotting.

RESULTSThe hens in TOCP group showed paralysis gait at the end of 21-day experimental period. The levels of NFs proteins in spinal cords changed obviously. Compared with control, the NFs in pellet showed a dramatic decrease on day 10 and then followed by a recovery. In the supernatant, the NFs proteins showed similar changes, which decreased significantly on day 10 and almost recovered control on day 21. Such as, NF-L, NF-M and NF-H decreased by 51%, 86% and 38% on day 10. The OPIDN signs were not observed in PMSF + TOCP group, and imbalances of NFs were obviously alleviated. Compared with control, only NF-M in pellet increased by 21% (P < 0.05) on day 21, others remained no changes; The levels of NF-H and NF-M in supernatant respectively increased by 19% and 35% on day 21, others were no significant statistical differences.

CONCLUSIONTOCP may induce imbalance of NFs levels in progress of OPIDN, and PMSF pretreatment may protect animals from OPIDN by reducing above changes, which may explain that TOCP-induced imbalance of NFs may be connected with the occurrence and development of OPIDN.

Animals ; Chickens ; Female ; Neurofilament Proteins ; drug effects ; Phenylmethylsulfonyl Fluoride ; pharmacology ; Protein Subunits ; drug effects ; Spinal Cord ; drug effects ; metabolism ; pathology ; Tritolyl Phosphates ; toxicity

BACKGROUNDPatients with myelodysplastic syndrome (MDS) display a very diverse pattern. In this study, we investigated prognostic factors and survival rate in adult patients with MDS refractory anaemia (MDS-RA) diagnosed according to French-American-British classification and evaluated the International Prognostic Scoring System (IPSS) for Chinese patients.

METHODSA multi-center study on diagnosis of MDS-RA was conducted to characterize the clinical features of Chinese MDS patients. The morphological criteria for the diagnosis of MDS-RA were first standardized. Clinical data of 307 MDS-RA patients collected from Shanghai, Suzhou and Beijing from 1995 to 2006 were analyzed using Kaplan-Meier curve, log rank and Cox regression model.

RESULTSThe median age of 307 MDS-RA cases was 52 years. The frequency of 2 or 3 lineage cytopenias was 85.6%. Abnormal karyotype occurred in 35.7% of 235 patients. There were 165 cases (70.2%) in the good IPSS cytogenetic subgroup, 44 cases (18.7%) intermediate and 26 cases (11.1%) poor. IPSS showed 20 (8.5%) categorized as low risk, 195 cases (83.0%) as intermediate-I risk and 20 cases (8.5%) as intermediate-II risk. The 1-, 2-, 3-, 4- and 5-year survival rates were 90.8%, 85.7%, 82.9%, 74.9% and 71.2% respectively. Fifteen cases (4.9%) transformed to acute myeloid leukaemia (median time 15.9 months, range 3 - 102 months). Lower white blood cell count (< 1.5 x 10(9)/L), platelet count (< 30 x 10(9)/L) and cytogenetic abnormalities were independent prognostic factors by multivariate analysis, but age (= 65 years), IPSS cytogenetic subgroup and IPSS risk subgroup were not independent prognostic factors associated with survival time.

CONCLUSIONSChinese patients were younger, and had lower incidence of cytogenetic abnormalities, more severe cytopenias but a more favourable prognosis than Western patients. The major prognostic factors were lower white blood cell count, lower platelet count and fewer abnormal karyotypes. The international prognostic scoring system risk group was not an independent prognostic factor for Chinese myelodysplastic syndrome patients with refractory anaemia patients.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Anemia, Refractory ; etiology ; mortality ; Asian Continental Ancestry Group ; Child ; China ; Female ; Humans ; Male ; Middle Aged ; Myelodysplastic Syndromes ; complications ; mortality ; Prognosis

OBJECTIVETo examine risk factors of chronic obstructive pulmonary disease (COPD) deaths in Chinese military elderly men.

METHODSA cohort analytic study was carried out in Xi'an, China. A total of 1268 retired military males aged 55 or older were examined in 1987 and followed for 18 years. Main outcome measures were all causes and COPD deaths.

RESULTSThe total person-years of follow-up from 1987 until June 2005 was 18 766.28. The mean follow-up time was 14.35 years; A total of 491 had died, with 748 alive and 29 lost of follow-up. COPD was the second cause of death in all deaths (16.90%). Results Univariate analysis of Cox model showed that age, number of smoking cigarettes per day, duration of smoking, negative affairs and existing COPD were risk factors of COPD deaths and the relative risks [95% confidence intervals (CI)] were 1.13 (1.09-1.17), 1.04 (1.02-1.06), 1.03 (1.01-1.04), 1.81 (2.85-6.77) and 4.39 (2.85-6.77) respectively. Data from Multivariate analysis of Cox model showed that age, number of smoking cigarettes per day and existing COPD were risk factors of COPD death with relative risks [95% confidence intervals (CI)] as 1.10 (1.06-1.15), 1.03 (1.01-1.06) and 3.07 (1.90-4.98) respectively. The risks for deaths increased significantly with increasing amount and duration of smoking resulting from all causes and COPD. Compared with current smokers, former smokers had lower risks of total mortality(excess risk reduction of 66.67%).

CONCLUSIONCOPD was the second cause among all deaths in this cohort. Age, number of smoking cigarettes per day and existing COPD were the risk factors of COPD deaths which called for further survey to examine the relationship between quitting smoking and COPD deaths in this cohort.

Age Factors ; Aged ; China ; epidemiology ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Military Personnel ; Pulmonary Disease, Chronic Obstructive ; mortality ; Risk Factors ; Smoking ; adverse effects

OBJECTIVETo establish an optimized primary drug screen model of neuronal differentiation using P19 embryonal carcinoma cells.

METHODSThe final concentration of retinoid acid (RA), days of suspension culture, manner of adherent culture, suitable cell density and adherent culture medium were tested, respectively. Two stages of neuronal differentiation were examined based on morphological changes and immunocytochemistry analysis of neuronal specific protein β-tubulin III.

RESULTSOn d 8 of differentiation culture, neuron-like cells were observed with final concentration of 1 μmol/L RA. Neuron-like network was formed on d 16 of neuronal differentiation. β-tubulin III was positively stained on both stages, indicating P19 cells were differentiated into neurons.

CONCLUSIONThe model using RA to induce P19 embryonic carcinoma cells to differentiate into neuron-like cells has been successfully established, which may provide a rapid, phenotypic cell-based platform for primary screening of neurogenesis-promoting drugs.

Animals ; Cell Culture Techniques ; Cell Differentiation ; drug effects ; physiology ; Cell Line ; Embryonal Carcinoma Stem Cells ; cytology ; drug effects ; Mice ; Neurogenesis ; drug effects ; Neurons ; cytology ; metabolism ; Phenotype ; Tretinoin ; pharmacology ; Tubulin ; metabolism