The evaluation system of PBL teaching was constructed to develop PBL teaching in combination with the characteristics of medical courses. It covered students evaluation system, teacher's evaluation, and teaching pattern system in all aspects of teaching. The present study was carried out through repeated verification in many clinical medicine curriculum and many grades of students, and standardized assessment model, a more mature evaluation system, has been fully applied. All the indices of the evaluation system were comprehensive in contents, scientific, objective, manipulated easily and with good results, which is worth promoting the application of PBL teaching in the future.

BACKGROUND: Due to the source of conspecific heart transplanted organ is limited and it becomes more and more deficient, and porcine cardiovascular system and haemodynamics are very similar to that of human being, therefore, domestic and foreign scholars have paid more attention on the heterogeneic heart transplantation from swine to human, and there are more and more basic studies about it.OBJECTIVE: To compare the zero-stress state of ascending aorta and pulmonary artery trunk between swine of different months and healthy persons, which provides necessary vascular tissue reconstruction basis for anastomosing vessel of heterogeneic heart transplantation from swine to human being.DESIGN: Open experiment.SETTING: Laboratory of Biomechanics, Yunyang Medical College.MATERIALS: This experiment was carried out at the Laboratory of Biomechanics, Yunyang Medical College from October 2001 to September 2002. Human heart specimens were chosen from 6 male adult corpses who had no visible manifestation of cardiovascular diseases, aged 18 to 30 years. Informed consents were obtained from all the relatives. Totally 42 conspecific swine, aged one month, were also chosen and divided into 7 groups, named as 1,2,3,4,5,6 and ＞ 6 months groups respectively, with 6 in each group. Swine were anesthetized at 1,2,3,4,5,6,＞ 6 months respectively and sacrificed in each group.METHODS: The corresponding ascending aorta and pulmonary artery trunk were dissected and isolated. Each arterial anterior wall was labeled in situ with coloring pen, and then artery was shifted into the oxygen-saturated Kreb's solution. Five isometric vascular rings were divided along the axial direction, then each vascular ring was cut open along the radial direction. Opening angle of each vascular ring at zerostress state was measured and recorded by computer 20 minutes later(The included angel formed through connecting the middle point of inner wall of open vascular plane and two end points of inner wall). The experiment was conducted at room temperature 20-30 ℃. All the procedures of vascular samples were performed within 24 hours after subjects died.MAIN OUTCOME MEASURES: Measuring results of opening angle of ascending aorta and pulmonary trunk at zero-stress state of swine at different months and human being.RESULTS: ①Comparison of measuring results of opening angle of ascending aorta and pulmonary trunk between swine at different months and human being: Opening angle of ascending aorta of human being increased from (100.4±12.8)°at proximal end to (152.8±18.6)°at distal end. Opening angle of swine at different months increased from about 68°at proximal end to about 130°at distal end; Opening angel of pulmonary artery trunk of human being did not changed significantly along axial direction, and opening angel of pulmonary artery trunk of swine at different months increased from about 65° at proximal end to about 125°at distal end. There was significant difference of opening angle of ascending aorta and pulmonary trunk at zero-stress state between human being and swine (P=0.028 ＜ 0.05).But the opening angle of ascending aorta of human being was similar at the second segment to at the fourth and fifth segments of swine of different ages; Opening angle of each segment of pulmonary artery trunk of human being was close to that of proximal end (first and second segments) ofpulmonary artery trunk of swine.② Comparison of measuring results of ascending aorta and pulmonary artery trunk at zero-stress state of swine at different months: Opening angle of ascending aorta and pulmonary artery trunk of swine did not changed with the increase of age (P=-0.063 ＞ 0.05).CONCLUSION: Opening angels of ascending aorta and pulmonary artery trunk at zero-stress state are close in some segments between human being and swine, suggesting that corresponding ascending aorta or pulmonary artery trunk can mutually anastomose in some segments in the heterogeneic heart transplantation from swine to human, and the effect of age is not significant in vascular reconstruction.

Objective To observe the clinical effect of compound remifentanil etomidate on gastrointestinalendoscopy and treat-ment among aged patients .Methods Divided 400 aged patients who got painless gastrointestinalendoscopy and treatment into two groups ,where one was observation group(200 aged patients) that got compound remifentanil etomidate ,while the other was control group which got fentanyl combined propofol .Compared and observed two groups on oxyhemoglobin saturation ,heart rate ,systolic-pressure ,diastolic pressure ,incidence of adverse reaction ,recovery time ,and time of leaving operating room .Results There was no obvious difference between observation group and control group on oxyhemoglobin saturation ,heart rate ,systolicpressure ,diastolic pressure before examination(P>0 .05);while there was distinct difference between examining and reviving ,which showed statisti-cal significance(P<0 .05) .The incidences of bucking ,dysphoria ,respiratory depression ,nausea and vomiting ,and dizziness in the two groups respectively were 3% 、2% 、5% 、3% 、11% and 8% 、11% 、13% 、8% 、27% ,which indicated the incidence of adverse reac-tion in observation group was obviously lower than that of control group ,where there was statistical significance (P<0 .05) .The time of recovery and the time of leaving operating room in two groups respectively were (3 .5 ± 1 .3)min、(9 .5 ± 1 .5)min and (7 .5 ± 3 .4)min、(18 .5 ± 4 .6)min ,which showed the time of observation group was lesser than that of control group ,where there was sta-tistical significance(P<0 .05) .Conclusion During the gastrointestinalendoscopy to aged patients ,compound fentanyl etomidate was safety ,less adverse reaction ,efficiency ,and strong controllability .

In order to provide morphological data and theoretical basis for pig-to-human hepatic xenotransplantation, the difference in morphological parameters and vessel wall structural factors between human and porcine hepatic portal vein was studied. From human subjects and pigs of varying ages, hepatic portal veins were collected, paraffin-embedded and cut into sections. The histological structures were stained with HE, and elastin, collagen and smooth muscles were stained with Weigert, Aniline blue and orange G, respectively. Morphological parameters and relative contents of structural components were determined under microscopy and by computer image analysis system, respectively. The results showed that histological structures of human and porcine hepatic portal vein wall were similar. Caliber, wall thickness, lumen and wall area in pigs increased with age, all in linear correlation to months. Morphological parameters of 6- month-old pigs were similar to those of human. In pigs, collagen content increased gradually with months, elastin content remained relatively stable, smooth muscle content reached the peak at the 3rd month, and collagen/elastin (C/E) rose gradually. The contents of collagen and elastin in porcine hepatic portal vein wall were lower, while the content of smooth muscle was higher than in human, and C/E at the 5th and 6th month was similar to that in human. It is concluded that morphological parameters and contents of structural components of porcine hepatic portal vein vary with age. At the 6 month, its caliber, wall thickness, lumen and wall area are similar to those of human. There are differences in contents of structural components between human and pigs. However, in terms of C/E, mechanic properties of pigs at the 5th and 6th month mimic those of human, hence inosculation is viable in xenotrans-plantation between pigs and human.
Collagen/*analysis ; Elastin/*analysis ; Image Processing, Computer-Assisted ; Liver Transplantation ; Muscle, Smooth, Vascular/cytology ; Portal Vein/*anatomy & histology ; Portal Vein/chemistry ; Swine ; Transplantation, Heterologous

Objective To summary the experience of microsurgery of meningioma in skull base treatment. Methods To study the clinical data of 10 cases patients of meningioma in skull base who were subjected to microsurgery by using retrospective analysis. Among the 10 patients, there were 3 cases of meningioma of the olfactory groove. There were 2 cases of sphenoid ridge meningioma, meningioma in the middle cranial fossa, meningioma in the cerebellopontine angle respectively.There was 1 case of meningioma of velarium in temporal lobe. Results In 7 cases, the meningioma was completely removed. And in another 3 cases, the meningioma got subtotal resection. During and after the operation, there were no severe complications observed or death occurrence in all the 10 cases of meningioma patients. Two months post of operation,all patients got a significant amelioration in their symptoms. A total of 9 cases were followed up. There was 1 case of IIa type meningioma recurred. Conclusion To elevate the whole shearing rate of meningioma in skull base and reduce the mortality of it,it is most important for appropriate operative route selection and well mircosugical technique application.

Objective To study the effects of electromagnetic field (EMF) exposure on osteoporosis in ovariectomized mice. Methods Sixty 8-week-old female Kunming mice were divided into four groups at random: a sham operation group (group A), an ovariectomized group (group B), an EMF and ovariectomized group (group C) and a nilestriol and ovariectomized group (group D). Bilateral ovariectomies were performed on all mice except those in group A. The mice of group C were exposured to a 15 Hz, 1.0 mT electromagnetic field. The mice of group D were given at nilestriol 1.5 mg/kg/week. The bone mineral density (BMD) of the lumbar vertebrae was measured before the mice were sacrificed at the 12th week. Blood specimens were collected every two weeks to measure the ac-tivity of alkaline phosphatase (ALP) and the concentration of bone gamma-carboxyglutamic-acid-containing proteins (BGP), calcium and estradiol in the serum. Histological sections were taken to examine and analyze the changes in bone trabeculae in the lumbar vertebrae after 6 and 12 weeks. Results EMF at 15 Hz and 1.0 mT intensity signifi-cantly increased the activity of ALP and the concentrations of BGP and calcium in the serum. In addition, the absorp-tion of bone trabeculae in the lumbar vertebrae was significantly restrained. Conclusions EMF at 15 Hz and 1.0 mT can restrain the development of osteoporosis in ovariectomized mice.

Objective To study the effects of an electromagnetic field (EMF) on the expression of fibro-blast growth factor (FGF-2) and it' s receptor (FGFR-2) mRNA in rat bone marrow mesenchymal stem cells (BMSCs) in vitro. Methods Rat BMSCs were isolated and cultured in vitro. The subcultured cells were divided into different groups to be EMF stimulated at 1.0 mT. The expression of FGF-2 and FGFR-2 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). Results Different frequencies and durations of 1.0 mT EMF exposure induced FGF-2 and FGFR-2 mRNA expression in comparison to blank controls. The expression of FGF-2 mRNA reached a peak after stimulation at 15 Hz for 10 min, 50 Hz for 60 min and 75 Hz for 30 min. And the expression of FGFR-2 mRNA reached a peak after 30 minutes at all frequencies. At 1.0 mT with 30 min exposure, the expression of FGF-2 mRNA peaked after 50 Hz stimulation, and the expression of FGFR-2 mRNA peaked after stimulation at 75 Hz. Conclusions Moderate EMF stimulation can significantly increase the expression of FGF-2 and FGFR-2 mRNA in rat BMSCs in vitro.

Objective To study the expressions of aggrecan (Agc) Ⅰ and Ⅱ collagen and Sox9 by bone mar-row mesenchymal stem cells exposed to electromagnetic fields (EMFs) and it's mechanisms involved. Methods Bone marrow mesenchymal stem cells were isolated from Sprague-Dawley rats and cultured in vitro. The third passage cells were harvested and exposed to 15 Hz 1 mT EMFs for 8 h/d. The semi-quantitative reverse transcription-polyme-rase chain reaction (RT-PCR) technique was used to measure parathyroid hormon receptor related peptide (PTHrp) ,Agc Ⅰ and Ⅱ collagen and Sox9 mRNA. Western blotting was used to measure type Ⅱ collagen expression. After the inhibitor of protein kinase A (PKA) H-89 and the inhibitor of protein kinase C (PKC) Go-6976 ( 12 μm) were added, the effects of EMFs on Agc Ⅰ and Ⅱ collagen and Sox9 mRNA expressions were measured again by using RT-PCR, and Western blotting technique. Results The EMFs induced significant increase of mRNA expressions of PTHrp, Agc Ⅰ and Ⅱ collagen and Sox9 in comparison to the controls, and promoted type Ⅱ collagen protein expres-sion. The Agc Ⅰ and Ⅱ collagen expressions decreased after PKA pathway inhibitor H-89 and PKC inhibitor Go-6976 were added, but the mRNA expression of Sox9 was not affected. Conclusion This study shows 15Hz 1mT EMFs can promote mRNA expressions of Agc Ⅰ and Ⅱ collagan and Sox9 of cbondrogenesis differentiation markers in bone marrow mesenchymal stem cells. The effect is correlated with PKA and PKC pathways.

The aim of this study was to detect the relationship between age and biomechanical properties in porcine common bile duct (CBD). The CBDs of 50 Hubei white pigs aged 3-12 months were obtained. The experiment of pressure-diameter was conducted on the biomechanical experiment stand for soft tissues, and then the elastic modulus and compliance were calculated. The materials were transversely extracted, refrigerated, and sliced up before HE staining. The diameter and wall thickness of the CBD were measured by a computer image analysis system. The results showed that there was statistically significant difference in regard to the compliance of the porcine CBDs of different months (F = 59.69, P = 0.00). The compliance of the porcine CBD increased gradually with monthly age. However, after the pigs being aged 10 months, the compliance decreased gradually with monthly age. The compliance of the CBD of pigs aged 7-10 months was not significantly different (P > 0.05), but the compliance of the CBDs of pigs' aged 3-6 months and 11-12 months was significantly lower than that of pigs aged 7-10 months (P < 0.01). The changes in elastic modulus of porcine CBD with age were opposed to the changes in compliance. The results of the present study suggests that the in biomechanical properties of pigs' CBDs change with their ages, and the CBDs of pigs aged 7-10 months have good compliance. Thus, for the pig-to-human liver xenotransplantation, the livers of pigs aged 7-10 months, being chosen as donators, may be more conducive to matching.
Age Factors ; Aging ; physiology ; Animals ; Biomechanical Phenomena ; Biophysical Phenomena ; Common Bile Duct ; anatomy & histology ; physiology ; Compliance ; physiology ; Elastic Modulus ; physiology ; Swine ; Transplantation, Heterologous

ObjectiveTo perform pharmacology problem-based learning (PBL) and evaluate its effects.MethodsPBL was performed for the clinical medicine class of grade 2007 and the satisfactory degree of students to teaching effects was observed with questionnaire. Results The students thought that PBL teaching had substantial contents and proper schedule and increased learning interest. Students' participating degree, mutual communication and controlling discussion procedure were fine,which reached the expected learning objective. ConclusionsThe effects of PBL teaching were excellent and most of our students could accept it.